EPA-600/2-76-250
November 1976
Environmental Protection Technology Series
USE OF CLIMATIC DATA IN
ESTIMATING STORAGE DAYS FOR
SOILS TREATMENT SYSTEMS
Robert S. Kerr Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Ada, Oklahoma 74820
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate instrumentation, equipment, and methodology to repair or prevent
environmental degradation from point and non-point sources of pollution. This
work provides the new or improved technology required for the control and
treatment of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service. Springfield, Virginia 22161.
-------
EPA-600/2-76-250
November 1976
USE OF CLIMATIC DATA IN ESTIMATING STORAGE DAYS FOR
SOILS TREATMENT SYSTEMS
By
Dick M. Whiting
National Climatic Center
Environmental .Data Service
National Oceanic and Atmospheric Administration
Asheville, North Carolina 28801
Interagency Agreement
EPA-IAG-D5-F694
Project Officer
Richard E. Thomas
Wastewater Management Branch
Robert S. Kerr Environmental Research Laboratory
Ada, Oklahoma 74820
ROBERT S. KERR ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U. S. ENVIRONMENTAL PROTECTION AGENCY
ADA, OKLAHOMA 74820
-------
DISCLAIMER
This report has been reviewed by the Robert S. Kerr Environmental Research
Laboratory, U.S. Environmental Protection Agency, and approved for publication.
Approval does not signify that the contents necessarily reflect the views and
policies of the U.S. Environmental Protection Agency, nor does mention of trade
names or commercial products constitute endorsement or recommendation for use.
ii
-------
ABSTRACT
The number of days each year that Soils Treatment Systems may be inopera-
tive because of unfavorable weather conditions can be estimated from
analysis of daily climatological data. In cold regions each winter
season (Nov.-Apr.) is examined for a 20- to 25-year period. Each day is
defined as favorable, partly favorable or unfavorable using a set of
thresholds for temperature, precipitation and snow depth. A daily
accounting procedure adjusts the increase or decrease in storage on the
basis of the type of day and the drawdown rate. The maximum storage
days each year are summarized in a final table which also presents the
mean, the standard deviation, the unbiased third moment about the mean,
the coefficient of skewness and storage days for recurrence intervals of
5, 10, 25 & 50 years.
A separate program is used for stations in wet regions where the primary
constraint to land application is saturated soil. The daily mean tempera-
ture and precipitation are examined for a 20- to 25-year period using
the modified Palmer program. This program estimates the condition of
both the underlying and surface soil layers in an attempt to identify
periods when saturation occurs and runoff would result from additional
precipitation or application. The longest consecutive period of un-
favorable days each year is summarized in a table that also shows
estimated storage days at the 5, 10, 25 & 50th percentiles.
Chronological listings of the actual data and computations for the
entire period of record can also be furnished. Thresholds of most of
the parameters can be changed to suit individual systems. The program
can also be modified to examine the condition of the surface layer
during the growing season as an estimate of irrigation needs.
This report is submitted in fulfillment of Interagency Agreement EPA-
IAG-D5-F694 by the National Climatic Center, Asheville, North Carolina.
Work was completed on June 30, 1976.
111
-------
TABLE OF CONTENTS
Page
DISCLAIMER ii
ABSTRACT iii
CONVERSION TABLES vi
ACKNOWLEDGEMENTS vii
Sections
I CONCLUSIONS 1
II RECOMMENDATIONS 3
III INTRODUCTION A
IV ESTIMATING STORAGE CAPACITY IN COLD REGIONS 7
V ESTIMATING STORAGE CAPACITY IN WET REGIONS 10
VI DISCUSSION 13
VII REFERENCES 15
VIII APPENDIXES 18
A. The Computer Programs 19
B. Supplemental Information 49
C. Requests for Services 89
-------
CONVERSION TABLES
ENGLISH TO METRIC UNITS
Length:
Speed:
1 inch (in.) =25.4 millimeter (mm.)
= 2.54 centimeter (cm.)
1 foot (ft.) = 30.48 centimeter (cm.)
= 0.3048 meter (m.)
1 yard (yd.) = 91.44 centimeter (cm.)
= 0.9144 meter (m.)
1 statute mile (stat. mi.) = 1609.344 meter (m.)
= 1.609344 kilometer (km.)
1 mile per hour (mi. hr."1, mph) = 0.868391 knot (kt.)
= 0.44704 m. sec."1
= 1.609344 km. hr.~l
Density, Specific Volume:
1 pound per cubic foot (lb.ft.~3) = 0.0160185 grams
per cubic centimeter (g.cm.~3)
Pressure:
1 standard atmosphere (14.7 Ibs. in.~2) = 760 millimeters of
mercury (mm.Hg.)
1 millibar (mb.) = 0.750062 millimeters of mercury (mm.Hg.)
Temperature:
Celsius (C) = 5/9 (F-32) where F is temperature in degrees
Fahrenheit
Absolute (A) or Kelvin (K) = C + 273.16
-------
ACKNOWLEDGEMENTS
The support and assistance of many individuals within the several divi-
sions of the National Climatic Center (NCC) is acknowledged with sincere
thanks. The writer is grateful to Mr. Frank Quinlan, Chief, Climatological
Analysis Division and to Dr. Nathaniel Guttman, Chief, Statistical
Climatology Branch, NCC, for their suggestions and words of encouragement.
Others in the Center who provided special assistance include: Mrs. Irma
Lewis, Chief, Data Translation Branch, Mr. Ray Barr, Chief, Programming
Section, Mr. Coy Johnson, Programmer, Mrs. June Radford and Miss Dottie
Goodman, Statistical Climatology Branch, and personnel in the Audiovisual
Services and Photographic Laboratory of the National Climatic Center.
Appreciation is also extended to the Robert S. Kerr Environmental Research
Laboratory, Ada, Oklahoma for its support of this project, and especially
to Mr. Richard E. Thomas, Project Officer.
Special recognition is extended to Dr. J. R. Mather, Wayne C. Palmer and
others for their work in developing many of the techniques used in these
programs. The concept of assessing the water balance in the general
manner described was developed by the late C. W. Thornthwaite.
vii
-------
SECTION I
CONCLUSIONS
Engineers, planners, and designers of Soils Treatment Systems may need
an estimate of the number of days when land application would be un-
desirable due to certain weather conditions. If storage must be planned
during extended periods when application would result in surface runoff,
the programs developed can be used to estimate the duration of such con-
ditions. In addition, the modified Palmer program (EPA-2) might be
useful in estimating irrigation needs during the growing season.
The programs developed by the National Climatic Center, through support
of the Environmental Protection Agency, provide estimates of storage
requirements using 20 to 30 years of daily climatological data. Two of
them (EPA-1 and EPA-3) are designed for use at stations in cold regions,
while another (EPA-2) is best suited to those in wet regions. The EPA-3
program is similar to EPA-1 but examines daily maximum and minimum
temperatures instead of the daily mean temperature. In this program an
unfavorable (UNF) day is defined as one with precipitation of one-half
inch or more, snow depth one inch or more, or a maximum temperature less
than 40°F. A favorable (FAV) day is one with less than one-half inch
precipitation, snow depth less than one inch, a maximum temperature of
40°F or more and a minimum temperature of 25°F or more. Partly favorable
(L) days have less than one-half inch precipitation, less than one inch
of snow on the ground, maximum temperatures of 40°F or more, but with
minimum temperatures less than 25°F. On FAV days the decrease in storage
is equal to the daily flow (Q) minus the drawdown rate CDD). On 'L'
days, the increase (gain) in storage is equal to Q-(DD/2), while on UNF
days the increase in storage is equal to Q.
A final summary of EPA-3 includes the yearly storage values from which
the mean, standard deviation and other statistics are derived. Finally,
the estimated storage days are computed by the Pearson Type III method
for recurrence intervals of 5, 10, 25 and 50 years.
The programs represent a rather simple approach to a complex problem.
They deal almost exclusively with climatological factors rather than
biologic or hydrologic ones. In spite of the great variability in
soils, climate and waste characteristics, reasonable estimates of storage
requirements due to climate can be obtained from daily climatological
records.
-------
Estimates derived from these programs should be examined carefully to
determine if adjustments are necessary because of local conditions. No
program can account for all possible variables such as the quality and
concentration of the effluent, depth to water table, soil type and
condition, loading rates and others.
Hill [1] points out that the Thornthwaite method for estimating evapo-
transpiration from the mean daily temperature and length of day is
generally conceded to be a poor estimator for daily amounts. However,
it appears that in identifying wet spells neither evapotranspiration nor
the available water capacity of the soil significantly affects the
results; that is, when rainy spells occur, the amount of rainfall is
sufficient to saturate the soil regardless of its assigned capacity.
Estimates from EPA-2 based on 25 years of record for stations in wet
regions do not always fit a smooth pattern. Estimates range from 11 to
35 days in Louisiana, 12 to 33 days in Mississippi and 21 to 165 days in
Oregon. The greatest number of storage days due to saturated soil
occurs along the coast of Washington and Oregon.
A modification of EPA-2 examines the runoff and the condition of the
surface and underlying soil in defining unfavorable days. Additional
modification might be advisable in order to classify days as unfavorable
unless the computed soil moisture is lower than the proposed loading
rate. There are times when runoff is not indicated yet the underlying
layer (SU) is saturated and the surface layer (SS) is within a few
hundredths of an inch of being saturated. The program can be altered to
class such days as unfavorable. This feature is identified on the
listing by a percent following the EPA-2 indicator; for example, EPA-
2(10%) denotes a set of data processed using not only the runoff feature
in defining unfavorable days, but includes those days when the sum of
the surface (SS) and underlying (SU) layers is within the indicated
percent (10) of saturation. Of course, saturation is defined as the
assigned available water capacity (AWC) for that location. This feature
has the effect of extending the wet spells between a series of days with
runoff. It can also be useful in estimating irrigation needs during the
growing season since the moisture in the surface layer is indicative of
the amount available in the root zone. It should also prove useful in
estimating, along with other factors, the maximum loading rate during
certain times of the year.
Finally, the variability in the amount of storage needed from year-to-
year can be significant at some stations. For example, standard devia-
tions of 15 to 20 are common at stations having a mean of 45 storage
days. The yearly storage values can be used as input to the Gumbel
extreme value analysis which gives estimates of storage days for return
periods up to 100 years with confidence bands of + 34%.
-------
SECTION II
RECOMMENDATIONS
The programs defined as P03B75:NCC-EPA-1 or EPA-3 generally should be
considered at sites where the normal January temperature is colder than
40°F (4.4°C), while SOILMT:NCC-EPA-2 should be used in areas where the
normal annual precipitation is 50.00 inches (1266 mm) or more. The
selection of these arbitrary thresholds was made after processing a
number of stations on both programs. The transition zones are not
clearly defined and the 40°F temperature and the 50 inches of precipitation
are only rough approximations. It may be desirable in some cases to
process the data both ways, especially in the Pacific Northwest.
Each program was developed to accept variable thresholds which can be
changed to account for differences in soils, systems, etc.; however, the
basic programs remain intact. Sharp differences in temperature, pre-
cipitation, and soil can occur over very short distances, hence each
site should be examined on an individual basis. Consultation with
hydrologists, geologists, soil scientists, and other specialists is
highly recommended.
-------
SECTION III
INTRODUCTION
A need was expressed in 1974 by the Robert S. Kerr Environmental Research
Laboratory, Environmental Protection Agency, to find a way of using
climatic data to estimate storage days for Soils Treatment Systems.
Some thought was given to using soil temperature and soil moisture
measurements, but this was not possible because of the paucity of data.
The programs developed at the National Climatic Center (NCC) require
serially complete, long-term digitized data. This type of daily clima-
tological data is available for many locations in the NCC's tape library.
Once the data base had been selected, it was necessary to determine just
what constituted climatic constraints to land application. It soon
became apparent that a constraint for one system and location often was
not a constraint elsewhere. In addition, while cold and snow might be
definite constraints in some regions, prolonged rainy spells would be
the major deterrent in others. Add to these variables the different
types of soils, systems, types of effluents, etc. and one can sense the
misgivings with which this project was started.
There were one or two hopeful signs. First, if the user can specify the
types of weather unfavorable for a particular operation, those days can
be identified. Second, Palmer's program [2] to identify droughts might
be modified to define days when the soil was saturated and runoff would
occur. The development of these programs provided a method of estimating
storage days in cold and in wet regions. Only experience and observation
will reveal how well these programs work. No field tests or controlled
studies have been made; however, continued alterations are being made to
the programs.
Each program can accept variable input, i.e. different thresholds, in
order to be of maximum use. The basic programs remain standard, while
the adjustment factors can be changed to account for the variations in
soils, systems and climate. As a first approximation these programs are
being used with a set of threshold values which are applicable for
wastewater irrigation systems. Thresholds applicable for high-rate
infiltration systems and overland-flow systems will be developed later.
The U. S. Army Corps of Engineers has done a vast amount of research in
connection with soil trafficability. Much of their investigative work
[3] is geared toward developing programs that can predict the state of
-------
the soil at a given time and place. Other efforts have been centered on
the prediction of stream flow and with the hydrologic quality of soils
[4]. Nothing in the literature examined dealt with the problem of
identifying the frequency or duration of periods when the ground was
saturated, although a number of studies [5-12] examined the water balance
during the growing season.
The soil type and its condition more than any other factors generally
determine the amount of runoff. The Soil Conservation Service (SCS) has
completed surveys in many areas and has published detailed information
for various soil series that may be obtained at local SCS offices [13].
Although the available water capacity (AWC) may not be a major factor
in the programs discussed, it is an important soil property for other
reasons. It is often given in reports as estimated amounts of water, in
inches per inch of soil for specific soil layers. The following adjective
ratings refer to the sum total of available water from the surface to
bedrock, or to a depth of 60 inches.
Very Low < 3 Inches
Low 3 to 6 Inches
Medium 6 to 9 Inches
High 9 to 12 Inches
Very High > 12 Inches
The four major hydrologic soil groups, as described by the Soil Conserva-
tion Service, are presented here for information.
A. (Low runoff potential). Soils having high infiltration rates
even when thoroughly wetted. These consist chiefly of deep, well to
excessively drained sands or gravels. These soils have a high rate of
water transmission in that water readily passes through them.
B. Soils having moderate infiltration rates when thoroughly wetted.
These consist chiefly of moderately deep to deep, moderately well to
well drained soils with moderately fine to moderately coarse textures.
These soils have a moderate rate of water transmission.
C. Soils having slow infiltration rates when thoroughly wetted.
These consist chiefly of soils with a layer that impedes downward
movement of water or soils with moderately fine to fine texture. These
soils have a slow rate of water transmission.
D. (High runoff potential). Soils having very slow infiltration
rates when thoroughly wetted. These consist chiefly of clay soils with
a high swelling potential, soils with a permanent high water table,
soils with a claypan or clay layer at or near the surface, and shallow
soils over nearly impervious material. These soils have a very slow
rate of water transmission.
-------
The programs developed at the NCC appear to follow actual physical
processes rather well, at least as far as climatology is concerned. The
depletion rate in EPA-2 was introduced to offset a unique condition in
Palmer's original program. It can best be explained by saying that his
weekly and monthly accounting systems had no provision to carry-over
runoff. In the daily accounting, it became necessary to gradually
deplete the excess defined as runoff. Since only a percentage of the
surplus water runs off on any day [13], it was necessary to assign some
estimated amount to account for gravitational water that is made avail-
able as runoff in the following days. The amount lost each day depends
on, among other things, soil type, structure, and depth of the soil
layer.
It became clear that any attempt to introduce all of the variables
affecting storage was either not possible, or not justified on the
grounds of time and money. An empirical approach seemed to offer a
reasonable escape from this dilemma. Stations with different soil
groups (clay, loam, and sand) were processed using assigned depletion
rates (.50, .75, and 1.00 inch per day, respectively). The. only guide
used in selecting these numbers came from experience and observation.
For example, if the indicated amounts fall on saturated soil it will
very likely take at least one day for that particular soil to dry enough
so that application is possible. The programs discussed in this report
use limited input data in an attempt to attain certain objectives. Most
of the development discussed in the report focuses on irrigation-type
systems whose operation is influenced much more by precipitation than by
either overland-flow systems or high-rate infiltration systems.
One of the obvious limitations in this report is in the area of hydrology.
None of the programs discussed in this report provide information dealing
with the intensity, duration or amount of precipitation from individual
storms. The Office of Hydrology, National Weather Service has prepared
precipitation frequency analyses for all locations in the United States
[14, 15, 16]. Publications are available with generalized charts from
which the magnitude of 10-year 24-hour and 25-year 24-hour precipitation
amounts can be obtained for any location. Information about the areal
variability of rainfall, recurrence intervals, as well as information on
evaporation should be requested from that office. Other offices to be
contacted for related information include the U. S. Geological Survey,
the U. S. Army Corps of Engineers and the U. S. Department of Agriculture's
Soil Conservation Service.
-------
SECTION IV
ESTIMATING STORAGE CAPACITY IN COLD REGIONS
If a Soils Treatment System is designed to operate during the winter
months in regions where the normal January temperature is colder than
about 40°F (4.4°C), storage needs can be estimated by converting days
defined as unfavorable into days of storage using either the EPA-1 or
EPA-3 program. Temperature, snow depth, and precipitation are examined
each day during the months of November through April for a period of 20
to 25 years. The exact period depends on the completeness and length of
the digital record for the particular station.
The EPA-1 program [17] defines each day as favorable or unfavorable for
operation on the basis of the assigned thresholds. While these thresholds
can be varied, almost all stations processed on EPA-1 were assigned
thresholds of: mean daily temperature 32°F, 1.00 inch or more of snow
cover and 0.50 inch of precipitation as the threshold between favorable
and unfavorable days. The maximum storage capacity each winter is
estimated by a daily accounting system, where one day's flow is added to
storage on days classed as unfavorable, while on favorable days the
accumulated storage is reduced by one-half the daily flow. This amount
can be changed from station-to-station to match the expected drawdown
rate. The maximum storage estimated during each winter season is
printed out at the end of the season. A final summary is presented
showing the estimated storage days for each of the winter seasons along
with percentiles at the .05, .10, .25, and .50 levels. A detailed
chronological listing of the daily input can also be furnished that
gives one an opportunity to examine the accounting process from d^ay-to-
day. Cumulative degree days to base 32°F are also listed. A freezing
index is computed for each season and is defined as the difference, in
degree days, between the highest and lowest values on a cumulative
curve. This index can be considered a measure of the intensity of the
cold period as explained in an earlier publication [17]. In the event
the system is to be shut down completely during the winter, the duration
of the freezing period is usually a better measure of storage needs than
the estimate obtained from the favorable-unfavorable day computations.
When a high percentage of the annual precipitation falls in the form of
rain or drizzle and the mean daily temperature seldom falls below 32°F
(0°C) during the winter months, EPA-1 may not give reasonable estimates
of storage. Olympia, Washington is an example of such a station. The
-------
problem arises partly from the fact that precipitation can occur almost
every day for weeks between the months of November and April. The
amounts are often less than 0.50 inch, while at the same time the mean
daily temperatures are above 32°F. Although such days are defined as
favorable by EPA-1, it is obvious from a review of the daily listings
that land application would be undesirable during much of this time
because of saturated soil and EPA-2 should be used.
The built-in flexibility of each program is considered one of the principal
features since it permits each user to determine the thresholds for his
particular situation. One modification to EPA-1 eliminated the snow
depth and precipitation constraints entirely. This was done to use the
long-term experience at an existing high-rate infiltration system to get
an estimate of the temperature threshold for high-rate infiltration
systems. If a waste treatment system in a cold region has been operating
for many years without being seriously hampered by weather conditions,
it follows that similar systems should be able to operate in a similar
climate. The mean daily temperature threshold was reduced to a point
where the lowest storage estimate at the control station was reduced to
a minimum as a best approximation of a reasonable threshold value.
The station selected for this special processing was Lake George, New
York, which has operated on a 12-month basis for 40 years despite its
relatively cold climate. Spier Falls, New York, about 15 miles to the
south, was selected as the weather station with the most suitable climato-
logical record. The temperature threshold was lowered from 32° to 10° F,
and each day below this threshold was considered unfavorable. Storage
days were estimated using the same daily accounting system as before.
These values ranged from 21 days during the most unfavorable season, to
one day during the most favorable season.
With this background for the Lake George area, runs were then made using
the same 10°F threshold for La Crosse, Wisconsin, and Greenville, Maine,
again without regard to snow depth or precipitation. Table 1 gives the
results of these runs, along with comparative values based on standard
thresholds.
Another modification suggested by Parmalee [18] and Griffes [19] resulted
in the development of the EPA-3 program. The proposed changes to EPA-1
included the use of the daily maximum and minimum temperatures instead
of the daily mean temperature as the criteria for an unfavorable day.
In addition, the daily accounting system was changed slightly and the
summary table includes several additional statistics. The storage gain
on UNF days is equal to the daily flow (Q). On L days, the gain is
equal to the daily flow (Q) minus one-half the assigned drawdown rate,
while on FAV days the decrease in storage is equal to the daily flow
minus the drawdown rate (DD). The summary table shows the mean number
of storage days, the standard deviation of the samples, the unbiased third
moment about the mean and the coefficient of skewness. Finally, storage
days are computed using the Pearson Type III method. Detailed information
about the EPA-3 program can be found in Appendix A.
-------
Program: P03B75-NCC-EPA-1 (Modified)
Spier Falls, N.
Mean Jan. Temp.
(a)
21.0
14.0
18.0
10.0
8.5
3.0
9.5
7.0
8.0
3.0
5.0
2.5
4.0
4.5
6.0
3.0
5.5
3.5
3.5
4.5
2.0
1.0
YEAR
1969
1962
1960
1967
1970
1958
1963
1961
1964
1968
1966
1971
1955
1965
1954
1959
1956
1951
1958
1953
1950
1952
Y.
20.4 F
(b)
132.5
121.5
107.0
108.5
137.0
125.0
116.0
110.5
107.5
131.5
104.5
138.5
130.0
96.0
92.5
114.5
93.5
129.5
104.5
73.0
97.5
73.0
Greenville, Maine
Max
10%
21
17
139
135
Mean Jan. Temp.
(a)
25.0
30.0
29.5
20.0
30.5
20.5
30.5
13.5
13.5
24.0
10.5
12.0
15.5
18.0
18.5
12.5
13.0
6.5
8.5
15.5
6.0
7.0
9.0
31
30
YEAR
1970
1958
1971
1964
1960
1962
1967
1968
1955
1961
1949
1966
1963
1969
1956
1951
1954
1965
1959
1953
1950
1952
1957
12.5 F
(b)
164.5
149.5
172.0
152.0
152.0
158.0
122.0
176.0
160.5
146.5
147.0
153.5
145.5
150.0
139.0
156.5
146.0
164.5
157.5
136.0
132.5
131.5
152.5
176
169
La Crosse, Wis.
Mean Jan. Temp.
(a)
13.5
18.5
19.0
20.5
20.0
8.0
7.5
12.5
15.0
12.5
15.0
13.0
12.0
6.0
11.5
8.0
5.0
17.0
12.0
3.0
7.5
13.0
10.0
7.0
11.0
21
19
YEAR
1964
1950
1958
1970
1962
1955
1949
1961
1971
1968
1969
1948
1951
1966
1956
1954
1959
1965
1972
1952
1957
1963
1960
1953
1967
16.1 F
(b)
123.5
133.5
123.0
119.5
98.0
133.0
113.5
119.0
120.5
109.5
108.5
104.0
119.0
107.0
98.0
112.5
115.5
80.0
97.0
111.5
95.5
90.0
70.0
84.5
76.0
134
127
Table 1 Estimated annual storage days based on
(a) mean daily temperature < 10° F, and
(b) standard thresholds of 5 32° F, snow depth > 1.00 inch and
precipitation > 0.50 inch
-------
SECTION V
ESTIMATING STORAGE CAPACITY IN WET REGIONS
The principal climatic constraint to land application at locations along
the Gulf States and the Pacific Northwest Coastal Region is prolonged
wet spells, rather than cold or snow. Program EPA-2 examines daily
climatological data during a 20 to 25 year period in an attempt to
identify days when the soil is saturated. If land application is undesir-
able during periods when surface runoff could occur, the longest consecutive
period defined as "wet" would be an estimation of storage needs. Palmer
[2] developed a program that examines weekly (and monthly) temperature
and precipitation in order to estimate the duration and magnitude of
abnormal moisture deficiency. His analysis yields successive index
values on weekly (or monthly) periods for State Climatic Divisions and
is currently used to identify meteorological drought.
In the original program, positive index values indicate that the moisture
supply from current or antecedent rainfall exceeded the amount required
to sustain the evapotranspiration, runoff and moisture storage which
could be considered as normal and appropriate for the climate of the
area. High positive values mean that fields are too wet to work, or
that rains have actually caused flooding. Rains in excess of the
estimated water use produce positive values of recharge until the soils
reach field capacity. Excess water then shows up as runoff. His
classification system is given in Table 2.
TABLE 2
Drought Classification
by Palmer
Index Degree
_> 4.00 Extremely wet
3.00 to 3.99 Very wet
2.00 to 2.99 Moderately wet
1.00 to 1.99 Slightly wet
.50 to .99 Incipient wet spell
.49 to -.49 Near normal
-.50 to -.99 Incipient drought
-1.00 to -1.99 Mild drought
-2.00 to -2.99 Moderate drought
-3.00 to -3.99 Severe drought
_< -4.00 Extreme drought
10
-------
The underlying concept of Palmer's work is that the amount of precipi-
tation required for the near-normal operation of the agricultural
economy of an area during some stated period is dependent on the average
climate of the area and on the prevailing meteorological conditions,
both during and preceding the period in question. Although his goal was
to identify droughts, he found it necessary to identify the entire range
of conditions from dry to wet, as shown above. His program appears to
work well in identifying droughts and thus became an obvious choice in
an attempt to identify prolonged wet spells.
A soil's ability to hold water is dependent upon the thickness of its
various horizons, its texture, bulk density, percentage of coarse
fragments and the organic content in the profile. The available water
capacity (AWC) is commonly defined as the amount of water available to
plant roots from the surface to bedrock, or to the unconsolidated non-
conforming material such as sand or gravel, or to an arbitrary depth in
the case of deep soils [13].
The effect of changing the AWC in the EPA-2 program does not change the
number of storage days significantly. This apparently is caused by
several factors, perhaps the most obvious is that when wet spells occur,
the rainfall is more than sufficient to saturate the soil regardless of
its assigned AWC. The surface layer of the soil is assumed to be
roughly equivalent to the plow layer. At field capacity it is expected
to hold one inch of the available moisture. This is the layer onto
which the rain falls and from which evaporation takes place. Therefore,
in the moisture accounting it is assumed that evapotranspiration takes
place at the potential rate from this surface layer until all the
available moisture in the layer has been removed. Only then can moisture
be removed from the underlying layer of soil. Likewise, it is assumed
that there is no recharge to the underlying portion of the root zone
until the surface layer has been brought to field capacity. The available
capacity of the soil in the lower layer depends on the depth of the
effective root zone and on the soil characteristics in the area under
study. It is further assumed that the loss from the underlying layer
depends on initial moisture content as well as on the computed potential
evapotranspiration (PE) and the available water capacity (AWC) of the
soil system.
The distribution of the estimated annual storage days for 25 years from
EPA-2 may be a good indicator of how the program is working. One knows
from experience that soils are neither always wet nor always dry.
Furthermore, the occurrence of extremely long wet periods is a rarity in
most places. The summary of the annual values for 25 years should
reveal an almost predictable distribution in terms of range and maximum
values. To be more explicit, a large number of years with no storage
days, or of estimates over 100 days due to saturated soil, would be
suspect almost everywhere except deserts and swamps.
11
-------
Palmer's original program dealt specifically with weekly and monthly
time periods and although he considered the antecedent conditions, it
was not necessary for him to be concerned with the amount of runoff. In
the daily accounting, the assigned depletion rate serves to approximate
the actual drying rate of the soil. It is essential to the program, but
it can be changed to suit different conditions. This artificial method
of gradually reducing the excess daily runoff Is simply a means of
accounting for the long-term effect of extremely heavy rainfall. It is a
way of describing the continuing restrictive factors of daily amounts
over and above that which would just cause saturation. The program
defines a day as unfavorable whenever the amount of moisture in the
surface soil (SS), plus that in the underlying soil (SU) and the accumulated
daily runoff depleted by a constant (SRO) is equal to or greater than
the assigned AWC.
About 75 stations have been processed on the original EPA-2 program that
defines a day with runoff as unfavorable. Examination of the daily
listings for a number of stations revealed some interesting conditions.
Days following those with runoff frequently showed a moisture content in
the surface layer very close to saturation. Since the surface layer had
not dried out enough to accept the intended amount of application, these
days should also be classed as unfavorable and the string of storage
days continued. The program was modified to check the amount of moisture
in the surface (SS) layer as well as the runoff and to class either
condition as unfavorable. The amount of moisture in the surface layer
at saturation is always 1.00 inch, with the remainder of the AWC assigned
to the underlying layer (SU). Thus, if one selects 0.10 inch as the
daily application rate it may be necessary to consider days with SS
equal to or greater than 0.90 inch as unfavorable along with those when
saturation is indicated. When this feature is used, the program indicator
is followed by the percent of SS being considered. For example, in the
case stated above, the indicator would be EPA-2(10%); if the application
rate was 0.20 inch, the indicator would be EPA-2(20%), etc. This simply
says the amount of moisture needed before the surface layer is saturated
is the difference between the amount of moisture in that layer and 1.00
inch. This feature may also be useful to planners in estimating irrigation
requirements in some areas. Additional changes would have to be made to
include a check on the amount of moisture in both SS and SU. The general
concept would be to establish minimum moisture needs and then analyze
the daily data in terms of the frequency, duration and even total moisture
deficit by months, or other time periods.
Examination of the daily listings from EPA-2 shows that most of the wet
periods occur during the winter months when evapotranspiration is
lowest. The heavy rains of summer do not often result in significant
wet spells for a number of reasons. The soil is more likely to be at
less than capacity and therefore, in need of recharge. Also, evapo-
transpiration rates are highest during the growing season. Detailed
information about the EPA-2 program is given in Appendix A.
12
-------
SECTION VI
DISCUSSION
Daily weather reports from the principal observing stations usually
include measurements of a number of elements, such as temperature,
precipitation, snowfall, snow depth, winds, relative humidity, sunshine,
sky cover, etc. These observations have been reported regularly from a
network of about 300 stations in the United States for many years, but
have been placed on magnetic tape only since about 1948. This network
is staffed by meteorologists and most of the stations are located at
airports.
Another important source of weather reports is the cooperative network
of approximately 10,000 to 12,000 stations. These stations are operated
by dedicated volunteers from all walks of life who are making a sig-
nificant contribution to climatology. Daily reports from this network
generally consist of temperature, precipitation, snowfall, snow depth
and remarks about unusual weather events. Some networks report only
precipitation and river stages, while others include soil temperature
and soil moisture measurements. State universities and other interested
organizations have made a special effort to place these climatological
observations on magnetic tape prior to 1948. Several hundred stations
now have digitized record as far back as 1895, or earlier.
In general, observing networks have been established primarily to
provide specific weather information to a particular segment of the
economy. Some are multi-purpose, of course, and most overlap to some
degree. Aviation, hydrology and agriculture are a few examples that
need unique and different measurements of the environment. Weather
forecasting probably has the broadest base of all in its use of weather
observations on a current, or real-time basis. The operational use of
weather data is only part of the total picture. Most weather records
forwarded to the NCC are edited, sorted and placed in magnetic tape
files for future processing. While statistical analysis of climatological
data can be very useful, it also has limitations.
One of the first steps in applying climatological data to a specific
problem is to insure the presence of an adequate base in digital form
(magnetic tape). Consideration should be given to the quality, complete-
ness and length of record, as well as having a large number of stations
well distributed throughout the country. The tape decks meeting the
above criteria at the NCC are TD-30 and TD-486.
13
-------
Inventories should be reviewed for completeness before the data can be
processed by the programs discussed in this report. If the requested
record is inadequate, a substitute station must be used, since a sig-
nificant number of missing elements or days can bias the results. This
means that climatological data from stations 50 to 75 miles from the
proposed site may sometimes be used. While each program furnishes
selected information about weather conditions at a station during the
past quarter of a century, the lack of refinement is obvious. Thresholds
to be assigned should be determined by specialists on the site since
numerous factors complicate the relationship between rainfall, temperature
and wet periods.
Although there is reason to believe that the output from these programs
can provide realistic estimates of storage requirements, the limitations
are so great in some areas that any measure of confidence may be misleading.
At best, these programs offer a simple approximation of storage based on
the examination of a few elements. Palmer, and others, developed the
basic computer program that provides a realistic picture of moisture
excesses and deficiencies many years ago. As more complete and longer
records become available, more refined methods of estimating storage
will be developed. Future studies will undoubtedly include such elements
as solar radiation, wind, moisture and temperature measurements at
selected levels above and below the ground, evaporation, precipitation,
and others. The present practice at some observing sites of recording
certain weather elements only during the growing season should be expanded
to include all months. In any case, it is hoped that some of the material
presented in this report will stimulate others to examine the data base
and respond with improved methods and techniques for estimating storage
days.
Finally, daily observations from the cooperative stations reflect weather
conditions that existed during the previous 24-hour period. These
periods do not coincide with calendar days, since most cooperative
observers take their observations in the morning (7 a.m.), or in the
evening (5 p.m.). It is entirely possible for one or more of the reported
values to have occurred on the previous day. Since there is no real
solution to this dilemma, except by having all stations report on a
midnight-to-midnight basis, it is the practice in most climatological
data processing programs to ignore differences in the hours of observation.
For example, it is impossible to tell from the digital records, or
indeed, even from some of the original records from the 7 a.m. and 5
p.m. reporting stations, on which date the reported rain actually fell.
-------
SECTION VII
REFERENCES
1. Hill, Jerry D., "The Use of a 2-Layer Model to Estimate Soil Moisture
Conditions in Kentucky," Monthly Weather Review, Vol. 102, No. 10,
October 1974, 5 P-
2. Palmer, Wayne C.,'"Meteorological Drought," Research Paper No. 45,
U. S. Department of Commerce, Weather Bureau, Washington, D. C.,
February 1965, 58 p.
3. "Report of Conference on Soil Trafficability Prediction," U. S. Army
Engineer Waterways Experiment Station, Corps of Engineers,
Vicksburg, Mississippi, November 1966, 125 p.
4. Smith, M. H. and M. P. Meyer, "Automation of a Model for Predicting
Soil Moisture and Soil Strength" (SMSP Model), Miscellaneous Paper
M-73-1, U. S. Army Engineer Waterways Experiment Station, Mobility
and Environmental Systems Laboratory, Vicksburg, Mississippi,
January 1973, 120 p.
5. Thornthwaite, C. W. and J. R. Mather, "The Water Balance," Publications
in Climatology, Vol. VIII, Number 1, Drexel Institute of Technology,
Laboratory of Climatology, Centerton, N. J., 1955, 104 p.
6. Mather, John R., "The Climatic Water Balance," Publications in Climatology,
Volume XIV, Number 3, C. W. Thornthwaite Associates, Laboratory of
Climatology, Centerton, N. J., 1961, pp. 249-264.
7. Barger, G. L., Robert Shaw, and R. F. Dale, "Chances of Receiving Selected
Amounts of Precipitation in the North Central Region of the U. S.,"
Agricultural and Home Economics Experiment Station, Iowa State
University of Science and Technology, Ames, Iowa, July 1959, 277 p.
8. Barger, G. L., Robert Shaw, and R. F. Dale, "The Gamma Distribution from
2- and 3-Week Precipitation Totals in the North Central Region of
the U. S.," Agricultural and Home Economics Experiment Station, Iowa
State University of Science and Technology, Ames, Iowa, Dec. 1959,
183 p.
9. Barger, Gerald L., "Weather Planning for Direct Seeding of Southeastern
Pines," reprinted from "Direct Seeding in the South," 1959, 12 p.
15
-------
References - cont'd
10. Pengra, Ray F., "Seasonal Variations of Soil Moisture in South Dakota,"
Agricultural Economics Pamphlet No. 99, Agricultural Experiment
Station, S. D. State College, Brookings, S. D., February 1959.
11. Pierce, L. T., "A Practical Method of Determining Evapotranspiration from
Temperature and Rainfall," paper presented at the American Society
of Agricultural Engineers, Chicago, 111., December 1956, 6 p.
12. van Bavel, C. H. M. , "Agricultural Drought in North Carolina," Technical
Bulletin No. 122, North Carolina Agricultural Experiment Station,
North Carolina State College, Raleigh, N. C., June 1956, 35 p.
13. "Guide for Sediment Control on Construction Sites," U. S. Department of
Agriculture, Soil Conservation Service, Raleigh, N. C., March 1973,
122 p.
14. "Precipitation-Frequency Atlas of the Western United States," NOAA-Atlas-2,
U. S. Department of Commerce, National Oceanic and Atmospheric
Administration, National Weather Service, Hydrology, Silver Spring,
Maryland. Volumes I-XI, 1973, 50 p.
15. Technical Paper #40, Hydrology, National Weather Service, National Oceanic
and Atmospheric Administration, Silver Spring, Maryland, May 1961,
115 p.
16. Technical Paper #49, Hydrology, National Weather Service, National Oceanic
and Atmospheric Administration, Silver Spring, Maryland, May 1964,
29 p.
17. "Use of Climatic Data in Design of Soils Treatment Systems," U. S. Environ-
mental Protection Agency Office of Research and Development,
EPA-660/2-75-018, Corvallis, Oregon, June 1975, 67 p.
18. Parmalee, Donald M., Consultant, Alloway, New Jersey, Camp Edge Road,
personal correspondence, 1975.
19. Griffes, Douglas A., Metcalf & Eddy Engineers, Palo Alto, California,
personal correspondence, 1976
20. Thorn, H. C. S., "New Distributions of Extreme Winds in the United States."
In: "Journal of the Structural Division, Proceedings of the American
Society of Civil Engineers," Vol. 94, No. ST 7, July 1968, 12 p.
21. "Glossary of Meteorology," edited by Ralph E. Huschke, American Meteoro-
logical Society, Boston, Massachusetts, 1959, 638 p.
22. Holzworth, George C., "A Climatological Analysis of Pasquill Stability
Categories based on 'STAR1 summaries," Environmental Protection
Agency, Environmental Sciences Research Laboratory, Research Triangle
Park, North Carolina, April 1976, 51 p.
16
-------
References (cont'd)
23. "Evaluation of Land Application Systems," U. S. Environmental Protection
Agency, Technical Bulletin, EPA-430/9-75-001, Office of Water Program
Operations, Washington, D. C., March 1975, 182 p.
24. "Factors Involved in Land Application of Agricultural and Municipal
Wastes," U. S. Department of Agriculture, Agricultural Research
Service, Beltsville, Maryland, July 1974, 200 p.
25. Pound, Charles E. and Ronald W. Crites, Metcalf and Eddy Engineers,
"Design Seminar for Land Treatment of Municipal Wastewater
Effluents," Design Factors, Part I, Palo Alto, California, April 1975.
26. Sorber, C. A., "Protection of Public Health," Proceedings of the Conference
on Land Disposal of Municipal Effluents and Sludges," Rutgers Uni-
versity, New Brunswick, N. J., March 1973.
27. Cry, George W., "Effects of Tropical Cyclone Rainfall on the Distribution
of Precipitation Over the Eastern and Southern United States,"
Environmental Science Services Administration, U. S. Department of
Commerce, Washington, D. C., June 1967, 195 p.
28. "Environmental Guide for the U. S. Gulf Coast," National Oceanic and
Atmospheric Administration, Environmental Data Service, National
Climatic Center, Asheville, North Carolina, November 1972, 177 p.
29. "Environmental Guide for Seven U. S. Ports and Harbor Approaches," National
Oceanic and Atmospheric Administration, Environmental Data Service,
National Climatic Center, Asheville, North Carolina, February 1972,
166 p.
30. W. B. Langbein, "Water Yield and Reservoir Storage in the United States,"
Geological Survey Circular 409, U. S. Department of the Interior,
Geological Survey, 1959.
31. A. F. Meyer, "Evaporation from Lakes and Reservoirs," Minnesota Resources
Commission, St. Paul, Minn., 1942.
32. R. E. Horton, "Evaporation Maps of the United States," Transactions
Amercian Geophysical Union, Vol. 24, Part 2, April 1943, pp. 750-751.
33. "Water-Loss Investigations: Vol. 1 — Lake Hefner Studies," Geological
Survey Professional Paper No. 269, U. S. Geological Survey, 1954.
34. "Water-Loss Investigations: Lake Mead Studies," Geological Survey
Professional Paper No. 298, U. S. Geological Survey, 1958.
35. M. A. Kohler, T; J. Nordenson, and W. E. Fox, "Evaporation from Pans and
Lakes," Research Paper No. 38, U. S. Weather Bureau, 1955.
17
-------
SECTION VIII
APPENDIXES
Page
A. The Computer Programs 19
B. Supplemental Information 49
C. Requests for Services 89
18
-------
APPENDIX A
THE COMPUTER PROGRAMS
List of Figures and Tables
Figure 1
Table 3
Figure 2
Figure 3
Figure 4
Figure 5
Figures 6-8
Figure 9
Figure 10
Figure 11
Figure 12
Figures 13-18
Page
Estimated maximum annual storage days from 21
EPA-1 program
Selected information for stations, 22
EPA-1 program
Comparison between maximum annual storage days 28
estimated from EPA-1 and EPA-2 programs
Explanation of symbols used in the listings 29
from EPA-2
Flow diagram for the modified Palmer program 30
(EPA-2)
Daily listing from EPA-2 for Greenwood, MS, 33
Aug.-Oct., 1958, with summary table
Daily listing from EPA-2 for Olympia, WA, 34
Oct.1949-Mar.1950, with summary table
Storage days estimated from EPA-2 program 37
Summary tables showing annual estimated storage 38
days for four stations (EPA-2)
Outline of the procedure used in developing the 39
summary table for EPA-3 shown in Figure 12
Summary of 26 winter seasons at Lander, WY from the 40
EPA-3 program (see Figures 13-18 for the daily
listings)
Listing of daily data from EPA-3, Lander, WY,
Nov. 1948-Apr. 1949
41
19
-------
Figure I8a Estimated maximum annual storage days for return 4-7
periods to 100 years (Gumbel)
Table 4 Estimated storage days for indicated return 48
periods from the EPA-3 program
20
-------
I '
THE ESTIMATED STORAGE DAYS
ARE BASED ONLY ON CLIMATIC
FACTORS; THEREFORE. USERS
SHOULD EXERCISE CAUTION IN
USING THIS MAP. COORDINATION
WITH ENGINEERS. SOIL SPECIAL
ISTS AND OTHER CONSULTANTS
IS RECOMMENDED FOR A THOR
OUGH AND DETAILED ANALYSIS
OF THE PROPOSED SITE.
SHADING DENOTES REGIONS WHERt
THE PRINCIPAL CLIMATIC CONSTRAINT
TO LAND APPLICATION IS PROLONGED
WET SPELLS. SEE MODIFIED PALMER
PROGRAM FOR ESTIMATED DAYS OF
STORAGE FOR STATIONS IN THIS AREA
PUEKTO BICO /WD VIRC1H ISLAKDS
Fig. 1 Estimated maximum annual storage days from EPA—1 program
-------
STATION
BIRMINGHAM. AL
MADISON, AL
MOBILE. AL
MUSCLE SHOALS. AL
ONEONTA, AL
ST. BERNARD, AL
SCOTTSBORO. AL
SELMA, AL
THOMASVILLE. AL
ASH FORK, AZ
GANADO. AZ
CORNING, AR
DUMAS, AR
FAYEmviLLE, AR
GILBERT, AR
LITTLE ROCK, AR
NASHVILLE EXP STN, AR
NEWPORT, AR
WALDRON, AR
CEDARVILLE. CA
LOS ANGELES, CA
bALINAb.GA
SAN FRANCISCO. CA
SANTA CRUZ.CA
SUSANVILLE, CA
TAHOE CITY, CA
BOULDER, CO
DENVER. CO
DUSANGO, CO
FORT COLLINS, CO
LAMAR, CO
STRATTON, CO
TRINIDAD, CO
UJ
N
Ul
UJ
si
E Q
o °
z £
3 S
008
018
004
014
012
016
012
004
006
025
110
023
Oil
029
021
018
014
020
016
066
001
001
001
001
060
123
052
082
110
105
065
088
065
UJ
g
fe _
I i
gj Q
012
019
005
018
017
018
016
005
008
024
074
022
013
018
02 o
016
012
016
012
071
004
004
005
006
059
164
049
056
099
067
046
066
047
*
0
X uT
— Ul
Rl 3
Uj tD
UJ *—
£
0061
0075
0019
0089
0085
0100
0095
0037
0041
0115
0633
0150
0075
0145
0154
0091
0087
0094
0080
0437
0001
0001
0001
0001
0418
0758
0346
0563
0642
0587
0531
0571
0450
s!
S 0
< g
s iH
Z Ul
Ul (C
-J u.
013
C20
004
016
014
020
017
C04
007
045
114
024
C14
033
025
020
017
023
017
075
001
001
001
001
068
130
056
100
112
122
069
094
093
3
x w
ii
Ul u,
?. n:
51
015
021
006
021
020
021
020
006
009
040
078
022
021
031
023
019
015
022
013
072
004
004
007
007
061
169
058
065
116
071
053
102
065
>
tc.
3 <
< £
|S
44.2
41.2
51.2
41.3
41.9
40.9
41.1
49.1
47.4
36.8
27.5
37.7
43.7
37.1
37.3
39.5
41.9
40.2
40.8
29.6
54.5
50.0
48.3
48.3
29.9
28.2
33.0
29.9
25.9
26.8
29.3
29.7
31.0
o
i|
0 <
z 9
oc
o
241
215
298
230
219
204
210
262
242
155
129
207
223
181
179
23R
219
215
199
131
350
262
35o
279
121
075
148
150
106
140
160
153
156
0>
cc
Ul
24
22
20
25
24
20
25
23
20
22
21
2o
22
27
20
25
23
21
25
20
25
20
25
24
22
22
24
24
22
23
22
23
22
BRIDGEPORT, CT
083 064 0410 084
068
30.2
135 23
WILMINGTON. DE
062
053 0312
081
061
32.0 191
25
APALACHICOLA. FL
AVON PARK, FL
DAYTONA BEACH, FL
FT. MYERS* FL
HOMESTEAD, FL
JACKSONVILLE. FL
TAMPA, FL
WEST PALM BEACH, FL
001
001
001
001
001
002
001
001
003
002
003
003
003
003
004
004
0006
0001
0001
0001
0001
0006
OOO1
0001
002
coi
001
001
001
003
001
001
003
005
005
005
006
004
005
004
53.7
62.9
58.4
63.5
65.3
54.6
60.4
65.5
322
344
326
365
344
313
349
365
24
27
17
24
24
19
21
21
Table 3 Selected information for stations, EPA-1 program
22
-------
STATION
ATHENSi GA
AUGUSTA, GA
ATLANTA, GA
BLAIRSVILLE EXP STAtGA
MACON. GA
BOISE. ID
CAMBRIDGE- ID
LEWISTON. ID
POCATELLO, 10
CAIRO.IL
CHICAGO.IL/MIOWAY
HOOPES10N.1L
MOLINE11L
MT.VERNON.IL
PANA , IL
PEORIA.IL
BERNE. IN
COLUMBJS, IN
CRAWFORDSVILLE. IN
EVANSVILLE. IN
SOUTH BEND, IN
BELLE PLAINE. IA
DES MOINFS, IA
HAMPTON, IA
KEOSAUQUA. IA
LOGAN. IA
SHENANDOAH, IA
DODGE CITY, KS
GOODLAND, KS
HAYS, KS
HEALY, KS
HERINGTON, KS
INDEPENDENCE, KS
JUNCTION CITY, K
BOWLING GREEN, KY
LEXINGTON, KY
PADUCAH, KY
ARCADIA, LA
LAFAYETTE, LA
LAKE PROVIDENCE, LA
LEESVILLE, LA
MONROE' LA
SHREVEPORT, LA
WINNFIELD, LA
LENGTH OF FREEZE
PERIOD (10 M
008
004
012
035
004
085
115
050
116
022
093
095
110
076
076
095
OB9
077
090
060
104
128
128
140
091
114
101
066
093
090
073
084
034
059
032
073
041
007
003
007
004
006
005
005
ESTIMATED STORAGE
DAYS (10 «)
010
005
on
031
005
077
101
048
109
028
081
072
092
042
061
083
074
061
073
045
101
113
106
126
084
105
077
048
066
064
062
052
026
049
039
048
037
012
004
012
005
009
006
006
FREEZE INDEX (10 K)
(BASE 32°F)
0044
0026
0055
0154
0030
0476
1256
0505
1252
0179
0954
0746
1106
0342
0519
0906
0661
0472
0714
0343
0926
1387
1416
1788
OB75
1152
0822
0381
0614
0593
0463
0445
0224
0396
0217
0310
0228
0060
0015
0061
0036
0051
0047
0043
LENGTH OF MAXIMUM
FREEZE PERIOD (DAY!
010
005
014
053
004
094
122
063
125
035
129
119
135
080
086
129
101
087
101
084
132
135
136
146
119
128
119
094
121
129
094
092
041
069
036
084
047
009
004
Oil
005
006
006
005
ESTIMATED MAXIMUM
STORAGE DAYS
016
007
016
048
007
087
120
059
125
034
086
076
095
046
065
088
086
062
086
049
109
126
111
136
090
107
095
053
073
065
067
064
032
058
040
052
038
012
005
016
006
010
009
008
NORMAL JANUARY
TEMPERATURE
44.5
45.8
42.4
37.8
47.8
29.0
22.5
31.2
23.2
36.3
24.3
26.2
21.5
32.1
28.9
23.8
27.1
30.1
27.2
32.6
24.0
19.8
19.4
16.3
24.4
2U.6
23.8
30.8
27.6
27.8
29.9
29.1
33.9
28.7
35.6
32.9
36.0
45.6
51.9
46.0
49.7
46.7
47.2
48.4
GROWING SEASON
(DAYS)
221
219
236
172
240
159
117
179
142
230
192
170
174
191
186
181
160
167
163
216
165
155
175
144
168
162
167
184
157
167
164
185
196
175
204
198
209
246
275
252
243
253
272
240
•>
S
9
24
23
24
25
23
24
24
25
25
25
25
25
25
24
25
25
25
25
25
25
25
25
25
23
27
25
25
23
23
23
23
23
23
23
'25
25
25
22
25
25
21
25
25
21
Table 3 .Selected information for stations, EPA—1 program
23
-------
STATION
BAR HARBOR* ME
EASTPORT, ME
GREENVILLE. ME
BALTIMORE. MO
ADAWS. MA
8OSTON» MA
HAVERHILL. MA
WORCESTER. MA
Ul
IM
Ul
LENGTH OF FR
PERIOD (10 «)
111
124
158
028
126
084
U94
122
S
s
ESTIMATED SP
DAYS (1 OK)
126
122
169
053
117
080
102
118
*
0
»
FREEZE INDEX
(BASE 32°FI
0976
Iijl2
2268
01«3
1266
0418
0640
0953
11
X a
LENGTH OF MA
FREEZE PERIOI
120
127
159
033
132
089
112
133
|
x _
ESTIMATED MA
STORAGE DAYS
140
130
172
055
123
081
104
126
„
5
II
23.7
22.6
12.5
36.1
21.0
29.2
26.8
23.6
o
His
I1
g
156
174
110
200
127
217
181
148
YEARS
23
23
23
22
25
25
25
25
MUSKEGON, MI
124
116
1040
127
119 24.0
161
23
INTERNATIONAL FALLS.MN
MINNEAPOLIS. MN
PARK »APIDS. MN
ABERDEEN. MS
CLARKSDALE. MS
COLUMBIA, MS
MERIDIAN, MS
PONTOTOC, MS
STONFVILLE ExP STA, Ms
ST. LOUIS. MO
SALISBURY. MO
SPRINGFIELD. MO
TAPKIO. MO
WARSAW. MO
WEST PLAINS. MO
BILLING.5. MT
BOZEMAN. MI
D1LLON» MT
GREAT FALLS. MT
MILES CITY, MT
M1S500LA, MI
GRAND ISLAND, ME
IMPERIAL. NE
SCOITSBLUFF, NE
VALENTINE. NF
ADAVEN. NV
ELKO. NV
ELY, NV
LOVELOC<. NV
RENO, NV
161
141
159
008
017
003
006
010
Oil
075
082
040
098
043
038
128
134
138
12B
134
133
121
093
117
12B
085
124 -
133
083
058
168
143
155
Oil
nl6
006
008
014
013
044
054
039
084
037
033
100
144
128
091
123
121
098
082
075
104
086
117
120
061
050
3506
2174
3186
0051
OOB3
0020
0033
0077
0077
0367
0470
0274
0869
0296
0232
1342
1348
1647
1557
2 '456
1309
1173
0765
0»()4
1401
0425
1230
1362
0459
0374
164
146
164
013
020
004
Oil
013
012
085
090
047
119
050
040
139
137
139
132
13B
137
132
121
134
136
096
125
134
087
064
172
143
159
013
021
009
015
019
017
051
071
043
090
038
035
102
152
132
102
140
128
103
092
081
119
102
124
137
080
067
01.9
12.2
05.0
44.7
43.1
50.4
46.9
43.2
44.2
31.3
27.8
32.9
24.0
32.5
33.8
21.9
20.8
20.2
20.5
15.4
20.8
22.3
26.9
24.9
20.4
30.6
23.2
23.6
28.9
31.9
095
166
122
228
236
239
246
223
229
206
186
201
170
IBS
17R
132
107
099
135
150
095
151
150
135
146
119
089
126
135
141
23
23
24
24
25
24
24
24
23
25
25
25
22
23
25
25
23
25
25
25
25
25
25
25
25
24
25
25
25
25
Table 3 Selected information for stations, EPA—1 program
24
-------
STATION
LEBANON. NH
ATLANTIC CITY. Nj
NEWARK. NJ
TRENTON. NJ
ALRUOUEROUE, NM
ARTESIA.NM
CIMARRON, NM
CLAYTON. NM
CLOVIS. NM
SANTA FE.NM
BUFFALO. NY
ELVIRA. NY
POUGHKEEPS1E, NY
ROCHESTER. NY
SPIE" FALLS. NY
SYRACUSE, NY
NY
CANTON. NC
CHARLOTTE. NC
ELUAStTH CITY. NC
FAYETTEVILLE. NC
GREENSBORO. NC
HICKORY, NC
LAUR1N6URG. NC
MAYSVILLE. NC
RALF1GH, NC
SALISBURY. NC
ViELDON. NC
WILMINGTON, NC
WILSON. NC
BISMARCK, ND
DEVILS LAKE. HO
WILLISTON. NO
AKRON CANTON, OH
COLUMBJS, OH
1AYTON, OH
FINDLAY, OH
ADA, OK
BAPTLESV1LLE. OK
HOBART. OK
MADILL. OK
OKLAHOMA CITY. OK
PAULS VALLEY. OK
POTEAU. OK
LENGTH OF FREEZE
PERIOD (10 *>
136
040
070
064
034
013
074
049
018
095
119
120
089
124
125
117
127
023
010
010
008
016
013
006
009
on
010
015
004
OOP
146
158
144
103
084
084
106
017
022
020
013
022
013
016
ESTIMATED STORAGE
DAYS 110%)
135
032
054
053
024
013
034
035
015
065
103
104
086
115
135
115
126
r>35
nil
013
010
024
020
008
Oil
rU7
014
017
007
^11
140
156
141
087
071
069
08B
013
02O
018
010
018
014
012
FREEZE INDEX HOW
(BASESS°F)
1569
0138
0302
02BO
0159
0160
0296
0235
0149
0493
0948
1021
0760
0970
1405
0975
1467
0171
0052
0036
0045
0086
0070
0028
0040
POM
0061
0082
0023
OP44
3103
3533
2975
0761
0578
r>599
0772
0035
0170
0169
0069
0166
0091
0082
LENGTH OF'MAXIMUM
FREEZE PERIOD (DAYSI
137
045
082
U83
P57
013
O99
056
O18
095
126
125
108
125
138
125
132
052
010
Oil
013
023
020
009
013
021
016
021
006
Oil
148
165
147
109
087
092
130
020
025
026
018
026
016
018
ESTIMATED MAXIMUM
STORAGE DAYS
147
036
059
056
026
013
074
042
020
065
108
113
092
121
139
118
128
041
014
016
012
030
025
012
012
021
015
029
007
015
144
168
146
092
076
071
095
014
020
020
012
020
016
014
NORMAL JANUARY
TEMPERATURE
18.1
32.7
31.4
32.1
35.2
40.8
32.2
33.1
37.2
29.8
23.7
25.0
26.5
24.0
20.4
23.6
18.8
38.0
42.1
42.3
43.0
38.7
39.1
43.9
45.0
40.5
40.9
40.5
46.4
42.5
08.2
04.2
08.3
26.3
28.4
28.1
25.8
40.9
35.4
37.3
42.1
36.8
39.7
41.1
GROWING SEASON
(DAYS)
120
225
219
218
196
220
150
166
198
165
179
156
177
176
150
168
151
195
239
226
222
211
210
212
241
237
205
193
262
222
136
127
132
173
196"
165
160
220
210
210
227
223
207
212
YEARS
25
25
25
25
24
21
25
25
22
17
25
25
25
23
23
25
25
25
25
25
25
25
24
25
23
25
25
23
25
24
24
24
24
25
25
25
25
22
23
23
23
22
23
23
Table Z Selected information for stations^ EPA—1 program
25
-------
Is
STATION
BURNS* OR
EUGENE* OR
KLAMATH FALLS. OR
MEDFORO. OR
PFNDLE10N. OR
PORTLAND. OR
RFDMONDi OR
ROSEBURG. OR
oALEM. OR
ERIEi PA
PHILADEPHIA. p«
PITTSBURGH. PA
STATE COLLEGE. PA
wILLIAMoPORT* Prt
STH OF FREE;
00(10%)
z £
as
108
010
087
018
037
014
044
006
012
113
068
069
104
U93
MATED STOR,
5 (10 K)
p >•
82
102
026
089
020
042
027
049
OlO
023
098
057
049
094
088
EZE INDEX IK
[BASE 32°F)
UJ
CC
u.
0774
0119
O400
0085
0526
0094
0379
0056
0101
0741
0322
0421
0709
0726
STH OF MAXI!
EZEPERIODd
Z Ul
as
122
027
103
025
062
023
C75
008
028
114
083
085
113
098
MATED MAXII
4AGE DAYS
P O
5 K
119
032
091
022
052
037
071
015
029
109
J64
053
106
095
MAL JANUAR'
PERATURE
§3
ul
t-
25.2
39.4
29.7
36.6
32.0
38.1
30.2
40.9
38.8
25.1
32.3
28.1
27.0
27.2
WNG SEASON
(DAYS)
0
O
111
199
126
184
196
211
075
219
192
200
190
187
166
164
M
Ul
25
25
25
25
25
25
23
28
25
23
25
25
25
25
PROVIDENCE* RI
089 076
Ob26
090
080
26.4
197
24
CHARLESTON. SC
COLUMBIA, SC
CONWAY. SC
FLORFNCE, sc
RAINBOd LAKE. SC
ABERDEEN. 3D
BOOKINGS. SR
PIERRE. SD
CITY. SD
CHATTANOOGA. TN
CROSSVILLF. TN
KINGSPORT.TN
KWXVILLF. TN
MEMPHlo. TN
NASHVILLE. TN
CORPUS CHRIST I . TX
. TX
EL P\SO. TX
LU9BOCK. TX
LUFKIN. TX
* INLAND. TX
WJCHIFrt FALLS. fX
BLANRJNG, UT
HANKSVILLE. UT
LOGAN, UT
MILK3RD. UT
NPPHI. UT
SALT LAKF CITY, 'IT
003
005
004
005
007
OO4
145
144
136
128
01?
054
022
021
019
022
021
001
038
005
005
016
004
006
016
098
082
130
112
092
098
004
006
006
008
012
005
138
131
126
099
020
052
024
022
017
028
023
003
027
008
005
014
005
007
015
091
073
109
090
075
089
ooi a
0025
0024
0024
0041
OP21
2690
2365
2205
1291
0097
0322
0146
0125
0108
0150
0205
0003
0195
0052
004fl
OH8
0034
0058
0090
0623
0934
0931
1007
0675
07*5
004
005
005
006
009
004
148
147
142
136
020
085
022
035
022
032
031
003
051
007
006
018
006
007
018
109
090
131
129
109
107
006
007
008
009
012
006
142
136
136
1OO
02?
055
028
031
025
031
027
005
032
010
006
020
006
010
017
110
089
113
101
089
115
48.6
45.4
46.5
45.6
42.1
47.4
09.5
12.0
15.6
21.9
40.2
34.5
36.4
40.6
40.5
38.3
36.0
56.3
33.8
45.4
43.6
39.1
48.8
43.6
41.5
27.7
26.1
24.0
25.7
26.0
2B.O
294
252
240
241
210
252
137
137
155
150
229
176
190
220
23.7
224
191
306
185
239
243
204
231
232
216
143
156
165
128
137
202
24
25
26
25
25
25
25
24
25
25
25
20
27
25
25
25
25
21
24
25
24
24
24
24
24
25
24
21
25
23
25
Table 3 Selected information for stations, EPA—1 program
26
-------
5
3
3
STATION
BURLINGTON.
VT
3LACK5FONE» VA
HOT SPRINGS. VA
NORFOLK. VA
WASHINGTON.OC/NATIONAL
LONCjVlEW, WA
OLYMPIA.WA
SEATTLE. WA
SPOKANE. WA
SUNNYSIDE. WA
VANCOUVER* WA
WALLA WALLA, WA
WFNATCHFE* WA
3LUESTONE DAM,
CHARLESTON* WV
MORGANTOWN. WV
ASHLAND, WI
EAU CLAIRE. WI
GRFEN BAY, WI
LAC^OSSr, WI
MADISON, WI
RHINFLANDER, wi
wi
AFTON, »/Y
CASPAR, h/Y
GILLFTTE, *Y
ROCK SPRINGS, WY
WHFATLAND, WY
U
Ul
- s
si
3 £
138
016
080
013
039
021
034
022
105
058
028
036
093
065
065
072
147
144
140
139
134
146
145
149
136
134
145
C99
0 f
K 0
< c
15
w Q
134
025
066
015
034
029
035
033
100
05O
028
042
087
052
044
06n
148
141
135
127
119
149
145
144
095
108
136
058
x £
1 2
M <
Ul •
Ul
IT
u.
1800
OlOO
0338
0059
0122
ol04
0227
0081
0953
0536
0192
0476
0849
0322
0272
0486
2353
2339
1932
1925
1700
2344
2289
2163
1140
1229
1718
0536
II
Ss
* B
Z Ul
ul (C
-1 U.
143
026
101
017
062
028
034
034
124
102
933
054
110
084
084
085
149
148
148
146
146
147
150
159
138
125
151
127
I"
is
™ "
P O
vt (-
Ul Ut
136
031
067
022
047
049
045
036
106
059
034
051
122
058
049
070
149
147
139
134
125
156
148
156
101
113
142
066
ii
< £
II
16.8
38.3
31.6
40.5
35.6
38.2
37.2
38.2
25.4
30.5
38.4
33.4
26.6
31.1
34.5
31.5
12.1
11.7
15.4
16.1
16.8
12.3
11.3
14.3
23.2
21.7
19.2
28.9
z
o i
I-
oc
148
181
135
219
200
182
344
233
169
158
233
202
188
150
193
165
109
151
161
161
177
085
125
018
130
129
060
102
1C
Ul
25
24
22
25
25
24
23
25
25
25
23
25
22
25
25
25
22
24
25
25
25
21
21
25
25
22
25
25
Table 3 Selected information for stations, EPA—1 program
27
-------
to
00
Station
Alabama
Hobile
Selma
Thomaaville
Arkansas
Dumas
Little Rock
California
Los Angeles
San Francisco
Florida
Avon Park
Daytona Beach
Tampa
Georgia
Augusta
Kacon
Louisiana
Lafayette
Lake Providence
Leesville
Monroe
Shreveport
Wlnnfield
Mississippi
Aberdeen
Clarksdale
Columbia
Meridian
Pontotoc
Stoneville
Normal
January
Temp. (*F)
51
49
45
44
40
55
48
63
58
60
46
48
52
46
50
47
47
48
45
43
50
47
43
44
Normal
Annual
Precip. (in.)
67
52
56
50
49
12
20
55
50
49
43
44
57
53
54
50
45
55
53
49
61
52
55
50
EPA-1
6
6
9
21
19
4
7
5
5
5
7
7
5
16
6
10
9
8
13
21
9
15
19
17
EPA-2
15
20
25
19
12
5
13
13
8
16
10
12
12
19
35
12
11
16
24
18
33
14
20
17
General
Period
1949-73
1949-73
1953-74
1951-71
1949-72
1952-69
1949-72
1945-72
1955-73
1953-73
1949-72
1949-72
1948-73
1951-72
1950-73
1949-72
1949-72
1950-73
1951-72
1949-72
1947-73
1948-73
1949-71
1951-72
Normal Normal
January Annual
Station Temp. (°F) Freclp. (In.)
North Carolina
Charlotte
Raleigh
Ueldon
Wilmington
Oregon
Eugene
Bedford
Roseburg
Salem
South Carolina
Charleston
Columbia
Conway
Tennessee
Crosaville
Texas
Anarillo
Corpus Christ!
Dallas
El Paso
Wichita Falls
Washington
Longvleu
Olympia
Vancouver
Walla Valla
* This station
42
41
41
46
39
37
41
39
49
45
47
35
36
56
45
44
42
38
37
38
33
shows
42
43
43
54
43
21
34
41
52
46
52
57
20
29
36
8
27
46
51
40
16
145 storage days whe
EfA-1 EPA-2
14
21
29
7
32
22
15
29
55
27
5
10
6
17
49
45
34
51
12
14
11
11
35
21
22
36
24
15
9
24
11
13
15
0
8
60
65*
31
14
General
Period
1949-73
1949-73
1926-50
1949-73
1948-73
1948-72
1935-64
1948-73
1948-73
1949-73
1945-73
1953-73
1949-71
1951-72
1948-72
1948-72
1950-72
1948-73
1949-73
1924-50
1950-73
Fig. 2 Comparison between maximum annual storage days estimated from EPA—1 and EPA—2 programs
-------
LIST OF SYMBOLS
STA: Station
YR: Year (20 to 30 years of record)
MO: Month 01 » January, 02 = February, etc.
DA: 01 - 31
MN: Daily minimum temperature (°F)
MX: Daily maximum temperature (°F)
T: Daily mean temperature (°F)
P: Daily precipitation (inches), Trace - 0.00
SP: Available moisture in the soil at the start of a day. Saturation is assumed when SP = AWC (available
water capacity)
SS: Amount of available moisture in the surface soil at the end of a day.
SU: Amount of available moisture in the underlying soil at the end of a day.
PE: Daily potential evapotranspiration (Thornthwaite)
PL: Daily potential moisture loss
PR: Potential recharge; at the start of a day this is the number of inches required to bring the soil to
field capacity
R: Daily recharge; net gain in the surface and underlying soil
L: Daily moisture loss from the surface and underlying soil
ET: Daily evapotranspiration
DR: Depletion rate
RO: Daily runoff
ARO: Accumulated runoff. This is the sum of the previous days SRO and the current days runoff;
ARO = SRO'+RO
SRO: Accumulated daily runoff minus the depletion rate; SRO = ARO - DR
AWC: Available water capacity of the soil. At saturation, AWC = SS +• SU
UNF: "X" denotes an unfavorable day for land application because of possible surface runoff
(If SRO + SS + SU is equal to or greater than the available water capacity, the day is unfavorable)
Note: Symbols with a prime ( ') indicate conditions at the start of a day. Subscripts s and u indicate
"surface" and "underlying", respectively.
Constants which must be supplied for the station being analyzed are:
I, the heat index
b, a coefficient which depends on the heat index
g, the tangent of the station's latitude
W, the available water capacity of the soil minus 1.0 inch in inches
, Daily solar declination, in radians
To start the analysis two values must be assigned: SS' in inches (to hundrcths) of soil moisture available
in the surface soil at the start, and SU', in inches (to hundreths) of soil moisture available in the under-
lying soil at the start.
Fig. 3 Explanation of symbols used in the listings from EPA—2
29
-------
START
(Precipitation)
S'=SS'=SU'
SP=S'
SS'and SU' are developed duly
1.0- SP
(Potential Recharge)
(Mean Temperature °F
T < 32
PE = 0
(Potential Evaporation
I
32 < T < 80
-T > 80-
I
PE - antllog [k + b log (T-32)]kd, where
k - log .021 + b log 5.56 - b log I, and
. . 1 [,„ -1/1-C -g tan »)2 , „.,,]
kd ' T757 "n g tan i + -0157
PE - [sin
- .166] - .76]kd. where
Step A
= SS'-
PE
Fig. 4 Flow diagram for the modified Palmer program (EPA—2)
30
-------
ET - P + I, + L,,
(Evapotrarapintion)
Fig. 4 Flow diagram for modified Palmer program (EPA—2) cont'd.
31
-------
1
f
R = KS + KU
(Recharge)
L=
(Loss)
(Runoff)
RO > 0 •
• RO < 0•
ARO' = SRO' + RO
SRO = ARO' - DR
Step F = SRO + SS + SU
£
F > AWC-
F < AWC
I UNFAVORABLE
1
( FAVORABLE J
Return to Start
The original Palmer program that computes the drought severity indices continues
from this point and runs about as long as the portion shown here. Most of the
constants for EPA—2 are stored on a separate tape at NCC; however, some values
must be extracted from the earlier Palmer tabulations. This means that although
there are no restrictions on the use or dissemination of the programs, a consider-
able amount of time and effort are required to collect the necessary material. In
addition, a 20 to 25-year period of record can be processed at the Center for less
than the cost of the program. Finally, the daily data must be purchased along with
the program for each station of interest.
Fig. 4 Flow diagram for modified Palmer program (EPA—2) cont'd.
32
-------
STATION DATfc MN MX
ss
su
PE
ET
RJ
SRO
UNF
223627 58 828 60 89 74.5
223627 58 829 63 90 76.5
223627 58 830 65 90 77.5
223627 SB 831 70 94 82,0
223627 SB 9 1 71 94 P2.S
223627 58 9 2 69 95 82. 0
223627 58 9 3 70 93 81.5
223627 58 4 70 89 79.5
223627 $8 5 71 BH 78.0
223627 98 6 69 93 81.0
223627 58 7 70 92 81.0
223627 58 8 67 90 78.5
223627 58 9 9 61 89 75.0
223627 58 910 63 92 77.5
223627 58 911 70 79 74.5
223627 58 912 68 79 73.5
223627 58 913 66 79 72.5
223627 58 914 65 84 74.5
223627 58 915 72 88 80.0
223627 58 916 72 90 81.0
223627 58 917 69 79 74.0
223627 58 918 67 79 73.0
223627 58 919 69 83 76.0
223677 58 920 72 76 74.0
223627 58 921 71 79 75.0
223627 58 922 69 84 76.5
223627 58 923 70 86 78.0
223627 58 924 73 88 80.5
283627 56 925 74 92 83.0
223627 58 926 73 92 82.5
223627 58 927 64 80 72.0
223627 58 928 55 75 65.0
223627 58 929 51 80 65.5
223627 58 930 56 76 66.0
223627 5810 1 51 69 60.0
223627 5810 2 48 70 59.0
223027 5810 3 53 63 58.0
223627 5810 4 57 75 66.0
223627 5810 5 57 78 67.5
223677 5810 6 54 84 69,0
223627 5810 7 60 81 70.5
223627 5810 8 64 84 74,0
223627 5810 9 6V -86 77.5
223627 581010 58 76 67.0
223627 581011 53 72 62.5
223627 581012 52 77 64.5
223627 581013 49 81 65.0
223627 581014 51 79 65.0
223627 581015 55 79 67.0
223627 581016 60 80 70.0
223627 581017 59 81 70.0
223627 581018 57 82 69.5
223627 581019 52 77 64.5
223627 581020 45 80 62.5
223627 581021 47 82 64.5
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.24
1.56
0.00
0.00
0.00
0.48
1.07
0.75
0.00
2.67
B.07
2.48
0.00
0.16
0.00
0.00
0.00
0.00
0.00
0.00
2.17
0.32
0.00
0.12
0.00
0.00
0.00
0.00
0,00
0.06
0.00
0.00
0.00
0.00
0.00
0,00
0.00
0.00
0.00
0.00
0.00
0.00
».07 0.00
2.92 O.UO
7.43 0.00
2.75 0.00
7.66 0.00
2.56 0.00
7.47 0.00
2.39 0.00
7.32 0.00
7.25 0.00
2.17 0.00
2.10 0.00
2.04 0.00
1.99 0.07
7.06 1.00
3.47 0,86
3.39 0.73
3.20 0.58
3.05 0.87
3.14 1.00
4.22 1.00
4.83 0.87
4.IS9 1.00
6.00 1.00
6.00 1.00
6.00 0.04
5.84 0.84
5. «4 0.65
5.65 0,45
5.45 0.25
5.75 0,13
5,13 0.04
5.04 0.00
4.96 1.00
6.00 1.00
6.00 O.V4
5.94 1.00
4.00 0.91
5.91 0.81
5.81 0.71
5.71 0.60
5.60 0.46
5.46 0.37
5.37 0.28
5.28 0.21
5.21 0,13
5.13 0.04
5.04 0.00
4.97 0.00
4.99 0.00
4.81 0.00
4.72 0.00
4.64 0.00
4.58 0.00
4.53 0.00
2,92
2.83
2.75
2.66
2.56
2.47
2.39
2.32
2.25
2.17
2.10
2.04
1.99
1.99
2.47
2.47
2.47
2.47
2.47
3.22
3.83
3.83
5.00
5.00
5.00
5.00
5.00
5.00
6,00
5.00
5.00
5.00
4.96
5.00
5.00
5.00
5.00
5.00
5.00
5.00
5.00
5,00
5.00
5.00
5.00
5.00
5.00
4.97
4.89
4.81
4.72
4,64
4.58
4.53
4.47
0.15
0.17
0.17
0.21
0.21
0.21
0.20
0.19
0,17
0.20
0.2C
0.18
0.15
0.17
0.15
0.14
0.13
0.15
0.19
0.19
0.14
0.13
0.15
0.14
0.15
0.16
0.17
0.19
0.20
0.20
O.U
0.0*
0.09
0.09
0.06
0.06
0.05
0.09
0.10
0.10
0.11
0.13
0.16
0.09
0.07
0.08
0.08
0.08
0.09
0.11
0.11
0.10
0.08
0.07
0.08
0.15
0.08
0.08
0.10
0.09
0.09
0.08
0.07
0.07
0.07
0.07
0.06
0.05
0.06
0.10
0.14
0.13
0.19
0.19
0.19
0.14
0.13
0.15
0.14
0.15
0.16
0.17
0.19
0.20
0.20
0.12
0.09
O.OB
0.07
0.06
0.06
0.05
0.09
0.10
0.10
0.11
0.13
0.16
0.09
0.07
0.08
0.08
0.08
0.08
0.09
0.09
0.08
0.06
0.05
0.06
2.93
3.08
3.17
9.25
3.34
3.44
3.53
3.61
3.68
3.75
3.83
3.90
3.9ft
4.01
3.94
2.53
2.67
2.80
2.95
2.6f
1.78
1.17
1.31
0.00
0.00
0.00
0.16
0.1»
0.35
0.55
0.75
0.87
0.96
1.04
0.00
0.00
O.OA
0.00
0.09
0.14
0.29
0.40
0.54
0.63
0.72
0.79
0.87
0.9A
1.03
1.11
1.19
1,2*
1.36
1.42
1.47
0.00
0,00
0,00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.07
0.07
0.00
0.00
0.00
0.29
0.29
0.29
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0,00
0.00
0.00
0.00
0,00
0.00
0.00
0.00
0,00
0.00
o.oo
0.00
0.00
0,00
0.00
0.00
0.00
o.oo
o.oo
0.00
0.15
0.08
0.00
0.10
0.09
0.09
0.08
0.07
0.07
0.07
0.07
0.06
0.05
0.00
0.00
0.14
0.13
0.15
0.00
0.00
0.00
0.13
0.00
0.00
0.00
0.16
0.01
0.19
0.20
0.20
0.12
0.09
0.08
0.00
0.00
0.06
0,00
0.09
0.10
0.10
0.11
0.13
0.10
0.09
0.07
0.08
6.08
0.08
0.08
0.09
0.09
0.08
0.06
0.05
0.06
0,15
0.08
0.08
0.10
0.09
0.09
0,08
0,07
0,07
0,07
0.07
0,06
0.05
0.17
0,15
0.14
0,13
0,15
0,19
0.19
0.14
0,13
0,15
0,14
0.15
0.16
0.17
0.19
0.20
0.20
0,12
0.09
0.08
0.09
0.06
0.06
0,05
0.09
0.10
0.10
0.11
0.13
0,16
0.09
0.07
0.08
0.08
0,08
0,08
0,09
0.09
0.08
0.06
0,05
0.06
0.00
0.00
0.00
u.oo
0.00
0.00
0.00
0,00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0,00
0,00
0,00
0,00
0.00
0.00
0,00
1.21
7,93
2.33
0.00
0.00
0,00
0,00
0,00
0.00
0.00
0.00
1.04
0.26
0,00
0,01
0,00
0,00
0.00
0,00
0,00
0,00
0,00
0,00
0.00
0.00
0,00
0,00
0,00
0,00
0,00
0,00
0,00
0.00
0.00
0.00
0.00
0.00
0.00
o.oo
o.oo
0.00
o.oo
0.00
o.oo
o.oo
o.oo
0.00
0.00
o.oo
0,00
0.00
0.00
o.oo
0.00
o.oo
0.46
7.64
9.22
8.47
7.72
6,97
6,22
5.47
4.72
3.97
3.22
3.52
3.02
8.27
1.53
0,78
0.03
0.00
0.00
0,00
0,00
0,00
0.00
0.00
o.oo
o.oo
o.oo
0,00
0,00
o.oo
o.oo
o.oo
0.00
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
016
STATION 223627 GREENWOOD, MS
AHCi 6.0 DEPLETION RATE'O.TS
HEG.DATE END.fUTE «0*YS
490102 490110 9
'00105 S00113 9
111213 511222 10
521230 330102 4
530429 530506 8
54^428 540505 8
750321 55032d 9
560201 560212 12
57H12 571124 13
J80919 581004 16
590417 590421 5
600301 600305 5
611208 611219 12
621224 621229 6
631213 631224 12
440422 640427 6
6502C8 650212 5
660209 660216 8
(•71214 671221 8
680103 680114 12
691229 700102 5
700105 700111 7
710508 710514 7
720101 720107 7
730314 730375 12
MAX PER TOTAL PERIOD OF RECORD
580919 581004 16
PfcRCENTILES
0.05
0.10
0.25
0.50
1AYS
14.7
12.1
11.5
8.0
Fig. 5 Daily listing from EPA—2 for Greenwood, MS, Aug. — Oct. 1958, with summary table
-------
STATION DATE UN MX
SP SS
su
PE
PR
ET
RO SRO
UNF
UJ
-P-
456114 4910 4 46 55 50.5
456114 4910 5 44 60 52.0
456114 4910 6 40 32 46.0
456114 4910 7 37 61 49.0
456114 4910 8 32 55 43.5
456114 4910 9 46 60 53.0
456114 491010 42 57 49.5
496114 491011 49 60 52.5
456114 491012 36 63 49.5
456114 491013 32 58 45.0
456114 491014 29 66 47.5
496114 491015 39 61 50.0
456114 491016 32 58 45.0
456114 491017 27 53 40.0
456114 491018 27 50 38.5
456114 491019 22 52 37.0
456114 491020 23 55 39.0
456114 491021 29 58 43.5
496114 491022 29 53 41.0
49A114 491023 39 49 42.0
456114 491024 37 60 48.5
456114 491025 36 51 43.5
496114 491026 43 53 48.0
456114 491027 47 5? 52.0
456114 491028 45 60 52.5
496114 491029 40 57 48.5
456114 491030 36 63 49.5
456114 491031 36 74 55.0
456114 4911 1 35 65 50.0
456114 4911 2 34 72 53.0
45&114 4911 3 3} 71 92.0
496114 4911 4 38 74 96.0
496114 4911 5 35 64 49.5
456114 4911 6 36 92 44.0
496114 4911 7 38 55 46.5
494114 4911 8 49 51 48.0
456114 4911 9 40 48 44.0
456114 491110 42 50 46.0
456114 491111 46 53 49.5
456114 491112 45 49 47.0
456114 491113 46 58 52.0
456114 491114 45 56 50.5
456114 491115 40 54 47.0
456114 491116 40 64 52.0
456114 491117 37 55 46.0
456114 491118 45 55 50.0
456114 491119 46 91 48.9
496114 491120 38 96 47.0
496114 491121 36 90 43.0
456114 491122 37 51 44.0
456114 491123 48 92 50.0
456114 491124 50 60 55.0
456114 491125 48 59 53.5
456114 491126 50 58 54.0
456114 491127 43 56 49.5
0.68 1.96 0.73 3.85
0.18 4.58 0.84 3.89
0.34
0.00
0.01
0.43
0.19
0.31
o.oo
0.00
0.00
0.04
0.00
0.02
0.00
0.00
0.00
0.00
0.00
0.00
0.02
0.01
0.25
1.24
1.36
.69 1.00 3.99
.99 0.95 3.99
.94 0.92 3.99
.92 1.00 4.28
.28 1.00 4.42
.42 1.00 4.66
.66 0.95 4.66
.61 0.91 4.66
.97 0.86 4.66
.53 0.85 4.66
.51 0.81 4.66
.48 0.81 4.66
,47 0'.79 4.66
.46 0.78 4.66
.44 0.76 4.66
.43 0.73 4.66
.40 0,71 4.66
.37 0.68 4.66
.34 0.66 4.66
.12 0.63 4.66
.30 0.84 4.66
.50 1.00 .69
.69 1.00 .99
0.01 7.99 0.96 .99
0,00 7.95 0.92 .99
0.00 7.90 0.85 .99
0.00 7.84 0.80 .99
0.00 7.79 0.74 6.99
0.00 7.73 0.69 6.99
0.00 7.68 0.62 6.99
0.00 7.61 0.57 6.99
0,00 7.56 0,54 6.99
0.19 7.53 0.70 6,99
0.25 7.68 0.91 6.99
0.14 7.89 1.00 7.00
0.38 8,00 1.00 7.35
1.16 8,15 1,00 8.46
2.89 9.46 1.00 11.00
0.11 12.00 1.00 11.00
0,19 12,00 1.00 11.00
0.00 12,00 0.96 11.00
0.00 11.46 0.91 11.00
0,04 11.91 0.92 11.00
0,04 11.92 0.91 11.00
0,00 11.91 0,87 11.00
0,00 11.87 0.83 11.00
0.05 11.83 0.86 11.00
0,88 11.86 1,00 11.00
0,63 12.00 1.00 11.00
0,36 12.00 1.00 11.00
0,46 15.00 1,00 11.00
2.50 12.00 1.00 11.00
1,00 12.00 1.00 11.00
0.06
0.06
0.04
0.05
0.03
0.07
0.05
0.06
0.05
0.04
0.05
0.05
0.04
0.02
0'.02
0.01
0.02
0.03
0.02
0.03
0.05
0.03
0.04
0.06
0.06
0.05
0.05
0.07
0.05
0.06
0.05
0.07
0.05
0.03
0.04
0.04
0.03
0.04
0.05
0.04
0.05
0.05
0.04
0.05
0.03
0.05
0,04
0,04
0,03
0.03
0.04
0.06
0.05
0.05
0.04
0.06 8.04
0.06 7.42
0.04 7.31
0.05 7.01
0.01 7.06
0.07 7.08
0.05
0.06
0.09
0.04
0.05
0.05
0.04
0,02
0.02
0.01
0.02
0.03
0.02
0.03
0.05
0.03
0.04
0.06
0.06
0.05
0.05
0.07
0.05
0.06
0.05
0.07
0.05
0.03
0.04
0.04
0.03
.72
.58
.34
.39
.43
.47
.49
.52
.53
.54
.56
.57
.60
.61
.66
.68
.70
.50
.31
.01
.05
.10
.16
.21
.27
.32
.39
.44
.47
.32
.11
0.04 4. On
0.05 3.65
0,04 2.54
0.05 0.00
0,05 0.00
0.04 0,00
0.05 0.04
0.03 0.09
0.05 0.08
0.04 0.09
0.04 0.13
0.03 0.17
0.03 0.14
0.04 0.00
0.06 0.00
0,05 0.00
0.05 0,00
0.04 0.00
0.62
0.12
0.12
0,00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0,00
0.00
0.00
0.00
0.00
0.00
o.oo
o.oo
0.00
0.00
0.00
0.21
0.21
0.21
0.00
0.00
o.oo
0,00
0.00
0.00
0.00
o.oo
o.oo
0.15
0.21
0.21
0.21
0.21
0.21
0.21
0,21
0,00
0.00
0.01
o.oo
0.00
0.00
0.02
0.02
0.02
0.02
0.02
0.02
0.02
0.00
0.00
0.00
0.05
0.02
a. oo
0.00
0.00
0.05
0.04
0.05
0.01
0.04
0.00
0.02
0.01
0.02
0.03
0.02
0.03
0.03
0.02
o.oo
0.00
0.00
0.04
0.05
0.07
0.05
0.06
0.05
0.07
0.05
0.03
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.04
0.05
0.00
0.01
0.04
0.04
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0,06
0.06
0.04
0,05
0.03
0.07
0,05
0,06
0,05
0.04
0.05
0,05
0,04
0.02
0,02
0,01
0,02
0,03
0.02
0.03
0,05
0,03
0,04
0,06
0,06
0,05
0.05
0.07
0.05
0.06
0.05
0.07
0,05
0,03
0,04
0.04
0,03
0.04
0.05
0,04
0,05
0,05
0,04
0,05
0,03
0.05
0.04
0,04
0.03
0.03
0.04
0,06
0.05
0,05
0,04
0.00
0.00
0.00
0,00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0,00
0.00
0.00
0,00
0,00
0,00
0,00
0,00
0,00
0.00
0.00
0,00
0.00
0.00
0,00
0.00
0.00
0,00
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
0,31
0,06
0.14
0.00
0,00
0.00
0.00
0,00
0.00
0.00
0.71
0.59
0,30
0.41
2,45
0.96
0.00
0,00
0,00
0,00
0,00
o.oo
0.00
o.oo
o.oo
0.00
o.oo
0.00
0.00
0.00
o.oo
o.oo
o.oo
o.oo
0,00
o.oo
0,00
o.oo
o.oo
0.00
o.oo
o.oo
0.00
o.oo
0.00
o.oo
o.oo
o.oo
o.oo
o.oo
o.oo
o.oo
0.00
o.oo
0.00
0.00
0.00
o.oo
o.oo
o.oo
o.oo
o.oo
0.00
o.oo
o.oo
0.00
0.00
o.oo
o.oo
1.70
1.90
X
X
X
003
X
X
X
X
X
X
STATION 45611* OLYMPIAD HA
AHC.12.0 DEPLETION RATE.0.75
8E6.DATE
491229
301119
S10109
920111
'30106
540113
351111
560210
5T0114
981217
591209
60011}
611212
621119
431112
641206
451223
661127
670313
681213
690103
701226
711202
720222
730101
MAX FOR
491225
END.DATE
500221
501209
510125
520126
530207
540130
551202
560309
570211
581230
591220
600129
611229
621205
631124
650110
660114
661220
670326
681224
690212
710130
720101
720313
730120
TOTAL PERIOD
500228
• DAYS
65
21
17
9
33
H
21
29
29
14
12
17
18
17
13
36
23
24
14
12
41
36
31
21
20
OF RECORD
65
PERCENTILES
0.05
0.10
0.25
0.50
DAYS
57.8
38.0
30.0
21.0
Fig. 6 Daily listing from EPA-2 for Olympia, WA, Oct. 1949 - Nov. 1949, with summary table
-------
STATION DATE MN MX
$p ss
su
PE
PL
ET
RQ $RO
UNF
Ut
496114 491128 41
496U4 491129 40
454114 491130 42
456114 4912 1 47
45*1 U 4912 2 33
4)6114 4912 3 30
496114 4912 4 29
494114 4912 S 39
4J6114 4912 6 29
496114 4912 7 26
456114 4912 8 2!
496114 4912 9 27
496U4 491210 24
496114 491211 26
496114 491212 32
496114 491213 36
496114 491214 37
496114 491215 36
4S61U 491216 32
454114 491217 32
496114 491218 26
496114 491219 17
456114 491220 22
496114 491221 36
456114 491222 42
456114 491223 40
456114 491224 33
456114 491225 37
456114 491226 39
456114 491227 42
456114 491228 46
496114 491229 31
496114 491230 31
496114 491231 30
496114 50 1 1 20
496114 50 1 2 6
456114 50 1 3 5
456114 SO 1 4 23
456114 50 1 5 24
456114 50 1 6 34
456114 90 1 7 32
456U4 50 1 8 30
456114 50 1 9 28
456114 50 110 31
496114 50 111 27
456114 50 112 18
496114 50 113 12
456114 50 114 6
456114 50 115 18
456114 50 116 16
456114 50 117 8
456114 50 118 13
456114 90 119 24
456114 50 120 38
456114 50 121 42
52 46.5
47 43.5
51 46.5
53 50.0
49 41.0
41 35.5
51 40.0
48 41.5
45 37.0
46 36.0
44 34.5
46 36.5
43 33.5
34 30.0
3fl 35.0
43 39.5
47 42.0
43 39.5
40 36.0
44 38,0
37 31.5
34 25.5
37 29.5
44 40.0
49 45.5
47 43.5
49 41.0
49 43.0
43 41.0
48 45.0
92 49.0
51 41.0
36 33.5
42 36.0
33 26.5
25 15.5
28 16.5
32 27.5
37 30.5
37 35.5
36 34.0
34 32.0
37 32,9
39 35.0
36 31.5
32 25.0
19 15,5
21 13.5
25 21.5
36 26.0
26 17.0
26 19.5
41 32.5
46 42.0
48 45.0
0.54
0.34
0,18
0.72
0,44
0.01
0.02
0.46
0.00
0,00
0.02
0,00
0.00
0.05
0,19
0.06
0.00
0.07
0,20
0,69
0,24
0.00
0,13
0.13
0.31
1.27
0,00
0,66
0.78
2.94
0.20
0,42
0.54
0.18
0,10
0.06
0,11
0.00
0.04
0.86
0,46
0,04
0.26
0.76
0.09
0.11
1.21
0.07
0.19
0.01
0.00
0.38
1.89
1.07
0.73
12.00
12.00
12. 00
12.00
12.00
it. 00
12.00
12.00
12.00
11.99
11.98
12.00
11.9V
11.99
12.00
12.00
12.00
11.98
12.00
12.00
12,00
12.00
12.00
12.00
12.00
12,00
12.00
11.98
12.00
12.00
12.00
12.00
12. 00
12.00
12.00
12.00
12.00
12.00
12.00
12.00
12.00
12,00
12.00
12.00
12.00
12.00
12.00
12.00
12.00
12.00
12.00
12.00
12.00
12.00
12,00
1.00
1.00
1.00
1.00
1.00
1.00
I'.OO
r.oo
0,99
0.98
1.00
0.99
0.99
1.00
1.00
1.00
0.98
1.00
1,00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
0.98
1.00
1.00
I'.OO
1,00
1.00
1.00
1.00
1,00
1.00
1.00
1.00
1.00
1.00
1.00
r.oo
1.00
r.oo
1.00
I'.OO
1.00
r.oo
r.oo
r.oo
1.00
1.00
r.oo
1.00
1.00
11,00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11,00
11.00
11.00
11,00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
11,00
11.00
11.00
11.00
11.00
11.00
11.00
11.00
0.03
0.03
0.03
0.04
0.02
0.01
0.02
0.02
0.01
0.01
0.00
0.01
0.00
0.00
0.01
0.02
0.02
0.02
0.01
0.01
0.00
0.00
0.00
0.02
0.03
0.02
0.02
0.02
0.02
0.03
0.04
0.02
0.00
0.01
0.00
0.00
0.00
0.00
o'.oo
0.01
0.00
0.00
0.00
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.02
0.03
0.03
0.03
0.03
0.04
0.02
0.01
0,02
0.02
0.01
0,01
0.00
0.01
0.00
0.00
0.01
0.02
0.02
0.02
0.01
0,01
0,00
0,00
0,00
0.02
0.03
0.02
0,02
0,02
0,02
0.03
0.04
0.02
0.00
0.01
0,00
0.00
0.00
0.00
0.00
0.01
0.00
0.00
0.00
0,01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.02
0.03
o.oo
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
0.00
0,01
0.02
0.00
0.01
0.01
0,00
0.00
0.00
0.02
0.00
0,00
0.00
0.00
o.oo
0.00
o.oo
0.00
0.00
0.02
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
'0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
0.02
0.02
0.02
0.02
0.02
0.02
0,02
0.02
0,00
0,00
0.02
0,00
0,00
0,00
0,00
0,00
0.00
o.oo
0,00
0.00
o.oo
0.00
0.00
0.00
0,00
0.00
0.00
0,00
0,00
0,00
o.oo
0.00
0.00
0.00
0,00
0.00
0.00
0.00
0.00
0.00
0,00
0,00
0,00
0,00
0.00
0.00
0.00
o.oo
0.00
0.00
o.oo
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0,00
0.00
0.01
0.01
0.00
0.01
0.00
0.00
0.00
0.00
0,02
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.02
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0,00
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.03
0.03
0.03
0.04
0.02
0.01
0.02
0.02
0.01
0.01
0.00
0.01
o.oo
o.oo
0,01
0.02
0.02
0.02
0.01
0.01
0.00
0.00
o.oo
0.02
0.03
0.02
0.02
0.02
0,02
0.03
0.04
0.02
0,00
0.01
o.oo
o.oo
o.oo
0.00
0.00
0.01
o.oo
0.00
0.00
0.01
0.00
0.00
0,00
o.oo
o.oo
0.00
o.oo
0.00
0.00
0.02
0.03
0,91
0.31
0.1J
0.68
0.42
o.oo
0.00
0,44
0.00
0.00
0.00
0.00
0.00
0,04
0.18
0,04
0,00
0.03
0.19
0.68
0.24
0.00
0.13
0.11
0,28
1,25
0,00
0,62
0.76
2.91
0.16
0.40
0,54
0,17
0,10
0,06
0.11
0.00
0.04
0.85
0,46
0.04
0.26
0.75
0.09
0,11
1.21
0,07
0.19
0.01
0,00
0.38
1.89
1.05
0.70
1,66
1.22
0,62
0.59
0.22
0.00
0,00
0,00
0.00
o.oo
o.oo
0,00
0,00
0,00
0.00
0,00
o.oo
0.00
0,00
0,00
o.oo
o.oo
o.oo
0,00
o.oo
0.90
0,00
o.oo
0,01
2.17
1.58
1.24
1.02
0,45
0,00
0,00
0,00
0,00
0.00
0.10
0,00
0,00
0,00
0.00
0,00
0,00
0,46
0,00
0.00
o.oo
0,00
o.oo
1.1*
1.44
1,39
X
X
X
X
X
X
X
X
014
X
X
X
003
X
X
X
X
X
X
X
X
X
009
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Fig. 7 Daily listing from EPA-2 for Olympia, WA, Nov. 1949 - Jan. 1950
-------
STATION DATE HN MX
SP SS
su
PE
ET
RO SRD
UNF
OJ
456114 50
496114 90
456114 90
456 1U 50
496114 90
45*114 90
456114 50
456114 50
4561U 50
456114 50
456114 50
456114 50
456114 50
456114 50
456114 50
456114 50
456114 50
456114 50
456114 90
456114 50
456114 50
456114 50
456114 50
456114 50
456114 50
456U4 50
456114 50
456114 50
456114 90
496114 90
456114 90
496114 90
496114 90
456114 90
456114 50
456114 90
496114 90
496114 90
456114 50
496114 90
496114 90
496114 90
456114 90
496114 90
496114 90
496114 90
456114 50
456114 90
496114 90
496114 90
496114 90
496114 90
496114 90
496114 90
496114 90
122
123
124
125
126
127
126
129
130
131
2 2
2 3
2 4
2 5
2 6
2 7
2 8
2 9
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
3 1
3 2
3 3
3 4
3 5
3 6
3 7
3 8
3 9
310
311
312
313
314
313
316
317
318
36 45 40.5 0.37 11.00 1.00 11.00
23 37 30.0 0.17 12.00 1.00 11.00
12 27 19.5 0.02 It. 00 I'.OO 11.00
2 31 16.5 0.06 11.00 I'.OO 11.00
28 37 32.5 0.20 11.00 I'.OO 11.00
22 30 26.0 0.00 12.00 1.00 11.00
8 31 19. 0.02 11.00 I'.OO 11.00
5 26 15. 0.00 12.00 I'.OO 11.00
6 27 16. 0.00 12.00 I'.OO 11.00
1 18 9. 0.03 12.00 1.00 11.00
4 36 20. 0.00 12.00 1.00 11.00
1 28 14. 0.08 12.00 I'.OO 11.00
27 40 >3. 0.15 12.00 1.00 11.00
33 43 18.0 0.91 12.00 1.00 11.00
33 42 37.5 0.55 12.00 I'.OO 11.00
34 44 39.0 0.22 It. 00 I'.OO 11.00
34 46 40.0 0.92 12.00 1.00 11.00
34 46 40.0 0.14 12.00 '.00 11.00
33 43 38.0 0.20 12.00 .00 11.00
37 44 40.5 0.11 12.00 '.00 11.00
38 46 42.0 0.95 12.00 .00 11.00
44 53 48.5 0.28 12.00 .00 11.00
42 52 47.0 0.07 It. 00 1,00 11.00
44 33 48.5 0.19 12.00 1.00 11.00
39 93 44.0 0.09 12.00 1.00 11.00
39 92 43.5 0.04 12.00 I'.OO 11,00
37 57 47.0 0.19 12.00 1.00 11.00
33 46 39.5 0.03 12.00 I'.OO 11.00
35 48 41,5 0.06 12.00 1.00 11.00
37 46 41.5 0.06 11.00 1.00 11.00
40 52 46.0 0.13 12.00 1.00 11.00
39 50 44.5 2.37 12.00 1.00 11.00
40 50 45.0 0.50 12.00 1.00 11.00
40 56 48.0 1.37 12.00 I'.OO 11.00
36 53 44.5 0.93 12.00 1.00 11.00
28 51 39.5 0.00 12.00 0.98 11.00
26 52 39.0 0.00 11.98 0.96 1UOO
27 57 42.0 0.00 11.96 0.93 11.00
39 50 44.5 0.62 11.93 1,00 11.00
48 53 51.5 2.00 12.00 1.00 11.00
41 49 45.0 1.12 12,00 1.00 11.00
38 49 43.5 0.25 It. 00 1.00 11.00
31 48 39.5 0.01 12.00 0.99 11.00
26 45 39,9 0.00 11,99 0.98 11.00
34 48 41.0 0.11 11.98 1.00 11.00
32 44 38,0 0.22 11.00 1.00 11.00
30 45 37,9 0.14 12.00 1,00 11.00
26 47 36.9 0.04 12.00 1,00 11.00
33 45 39.0 0.02 12.00 1.00 11.00
39 47 41.0 0.09 12.00 I'.OO 11.00
37 48 42.9 0.00 12.00 0.97 11.00
36 49 42.9 0.28 11.97 I'.OO 11.00
43 90 46.9 0.97 12.00 I'.OO 11.00
40 93 46.9 0.75 12.00 I'.OO 11.00
40 47 4>. 5 0.90 12.00 1,00 11.00
0.02
0.00
0.00
0.00
0.00
0.00
O'.OO
O'.OO
0.00
0.00
O'.OO
0.00
0.00
0.01
0.01
0.02
0.02
0.02
0.01
0.02
0.03
0.04
0.04
0.05
0.03
0.03
0.04
0.02
0.03
0.03
0'.04
0.03
0.04
0.05
0'.04
0.02
0.02
0.03
0.04
0.06
0.04
0.03
O'.OZ
0.01
0.03
0.02
0.01
0.01
0.02
0.03
O'.OS
0'.03
0.05
O'.OS
0.04
0.02
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0,00
0.01
0.01
0.02
0.02
0.02
0.01
0.02
0.03
0,04
0.04
0.05
0.03
0.03
0.04
0.0?
0.03
0.03
0.04
0.03
0.04
0,05
0.04
0.02
0.02
0.03
0,04
0.06
0.04
0.03
0.02
0.01
0.03
0.02
0.01
0.01
0.02
0.03
0.03
0.03
0.05
0.05
0.04
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
o.oo
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
0.00
0.00
0.00
0.02
0.04
0.07
o.oo
0.00
0.00
0.00
0.01
0.02
0.00
0.00
o.oo
0.00
0.00
o.oo
0.03
0.00
0.00
0.00
o.oo
0.00
o.oo
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
0.00
o.oo
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
o.oo
o.oo
0.00
0.00
0.00
o.oo
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.02
0,02
0.03
0.00
0.00
0.00
0.00
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.03
o.oo
0.00
0.00
0.00
0.02
o.oo
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
o.oo
0.00
0,00
0.01
0.01
0,02
0.02
0.02
0.01
0.02
0.03
0.04
0.04
0.05
0.03
0,03
0,04
0.02
0.03
0,03
0.04
0.03
0,04
0.05
0,04
0.02
0,02
0.03
0,04
0,06
0.04
0.03
0,02
0,01
0.03
0.02
0,01
0.01
0.02
0,03
0.03
0.03
0.05
0.05
0,04
0.35
0.17
0.02
0.06
0.20
0.00
0.02
0.00
0.00
0.03
0.00
0.08
0.15
0.50
0.54
0.20
0.90
0.12
0.19
0.09
0.92
0.24
0.03
0.10
0.02
0.01
0.15
0.01
0.03
O'.OS
0.09
2.34
0.46
1.32
0.49
0.00
o.oo
O'.OO
0.52
1.94
1.08
0.22
0.00
O'.OO
0.07
0.20
0.13
0.03
0.00
0.02
0.00
0'.22
0.92
0.70
0.86
0.99
0.41
0.00
0.00
0.00
0.00
o.oo
o.oo
0.00
0.00
o.oo
o.oo
o.oo
o.oo
o.oo
o.oo
0.15
o.oo
0.00
0.00
0.17
o.oo
o.oo
0.00
0.00
o.oo
o.oo
o.oo
o.oo
0.00
o.oo
1.59
1.30
1.87
1.62
0.87
0.12
0.00
0.00
1.19
1.92
0.99
0.24
o.oo
0.00
o.oo
o.oo
o.oo
o.oo
o.oo
o.oo
0.00
0.17
0.13
0.24
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
069
X
X
X
X
X
009
X
X
X
X
X
X
006
X
X
X
X
Fig. 8 Daily listing from EPA-2 for Olympia, WA, Jan. 1950 - Mar. 1950
-------
STATION
ALABAMA
BAY MINETTE.AL
BREWTON,AL
CLANTON.AL
MOB1LE»AL
SELMA.AL
THOMASVILLE,AL
ARKANSAS
DUMAS,AR
LITTLE ROCK.AR
CALIFORNIA
LOS ANGELEo.CA
SAN FRANCISCO,CA
FLORIDA
AVON PARK,FL
BELLE GLADE,FL
DAYTONA BEACH,FL
TAMPA,FL
GEORGIA
AUGUSTA,GA
MACON.GA
SAVANNAH,GA
LOUISIANA
HOUMA,LA
LAFAYETTE,LA
LAKE PROVIDENCE,LA
LEEi>VILLE«LA
MONROE,LA
NEW ORLEANS,LA
ST. JOSEPH,LA
SCHRIEVER.LA
SHREVEPORT.LA
WINNFIELD.LA
MISSISSIPPI
ABERDEEN,MS
BILOXI>MS
CANTON,MS
CLARKSDALEtMS
COLUMBIA,MS
1
6
6
6
6
6
6
6
6
7
7
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
,6
6
6
6
£
2
1949-73
1949-73
1949-73
1949-73
1949-73
1953-74
1951-71
1949-72
1952-69
1949-72
1945-72
1951-73
1955-73
1953-73
1949-72
1949-72
1949-72
1950-73
1948-73
1951-72
1950-73
1949-72
1954-73
1956-73
1948-73
1949-72
1950-73
1951-72
1951-73
1948-73
1949-72
1947-73
oc
o
a
MAR
MAY
DEC
APR
DEC
DEC
APR
MAY
FEB
JAN
JUN
OCT
SEP
JUL
FEB
JAN
SEP
MAY
JAN
DEC
APR
DEC
MAY
DEC
MAR
JAN
MAY
DEC
SEP
DEC
DEC
FEB
62
70
61
55
61
61
58
68
69
69
68
52
64
60
71
64
50
59
59
67
53
61
59
61
48
68
53
61
57
61
72
61
X
13
17
24
15
20
25
19
12
5
13
13
11
8
16
10
12
17
17
12
19
35
12
16
12
16
11
16
24
14
16
18
33
£
13
16
20
14
18
23
19
12
5
13
12
10
8
15
10
11
16
16
12
18
31
12
16
11
15
11
16
23
13
15
16
27
g
13
11
11
11
11
13
14
12
3
11
9
8
8
9
9
9
11
11
10
14
16
12
9
11
13
9
14
13
10
11
11
16
£
9
8
9
10
a
10
10
9
1
5
7
8
6
6
6
7
7
8
8
12
8
8
7
9
8
7
11
9
8
8
10
10
£
7
7
7
7
6
8
7
7
J
4
4
6
4
3
4
5
4
6
6
7
6
7
6
6
7
6
6
7
7
6
8
8
STATION
MISSISSIPPI
GREENWOOD. MS
JACKSON «MS
MERIDIAN, MS
PONTOTOC»MS
POPLARVILLEfMS
STONEVILLE«MS
VICKSBURG.MS
NORTH CAROLINA
CHARLOTTE, NC
RALEIGH.NC
WELOON»NC
WILMINGTON, NC
OREGON
EUGENE »OR
MEDFORD.OR
ROSEBURG.OR
SALEM, OR
SOUTH CAROLINA
CHARLESTON, SC
COLUMBIA, SC
CONWAYtSC
TENNESSEE
CROSSV1LLE,TN
TEXAS
ABILENE ,TX
AMAR1LLO.TX
BROWNSVILLE, TX
CORPUS CHRISTI ,TX
DALLAS, TX
HOUSTON, TX
WICHITA FALLS, TX
WASHINGTON
LONGVIEW.WA
OLYMPIA.WA
SEAITLE,WA
SEOUIM
VANCOUVER tWA
WALLA WALLA, WA
3
6
6
6
6
6
6
6
6
6
6
6
12
12
12
12
6
6
6
6
6
6
6
6
6
6
6
12
12
7
12
12
7
"
1949-73
1943-61
1948-73
1949-71
1945-73
1951-72
1942-62
1949-73
1949-73
1926-50
1949-73
1948-73
1948-72
1935-64
1948-73
1948-73
1949-73
1945-73
1953-73
1950-70
1949-71
1954-72
1951-72
1948-72
1948-72
1950-72
1948-73
1949-73
1949-73
1948-73
1924-50
1950-73
X
SEP
DEC
FEB
DEC
DEC
APR
DEC
JAN
JAN
JAN
JUL
JAN
DEC
JAN
DEC
JUN
JAN
JAN
JAN
JAN
FEB
SEP
SEP
APR
OCT
APR
DEC
DEC
DEC
MAR
JAN
JAN
58
61
61
67
61
58
61
73
63
30
50
49
64
50
49
73
63
70
66
61
60
67
67
66
49
57
49
49
49
56
50
69
i
16
12
14
20
25
17
17
12
14
11
11
35
21
22
36
24
15
9
24
6
11
12
13
15
14
8
60
65
47
6
31
14
S
15
12
13
19
22
17
17
12
13
11
10
34
19
20
34
21
14
9
24
6-
10
11
11
15
13
8
53
58
40
5
28
14
g
12
10
11
14
13
15
14
11
12
10
9
31
11
18
25
11
9
9
22
6
8
6
5
12
9
6
35
38
24
3
19
10
S
12
8
8
12
8
12
10
8
7
7
8
21
5
12
17
6
7
7
20
3
2
2
3
7
7
3
21
30
14
0
17
6
S
8
7
7
9
6
7
7
6
6
5
6
15
3
9
13
5
5
6
17
0
0
0
1
4
4
3
17
21
11
0
11
0
Fig. 9 Storage days estimated from EPA—2 program
-------
STATION 1 583 BAY MINETTE* AL
4HC» 6.0 DEPLETION RATI»0.75
US
00
BEC.OATE
490322
900831
910317
520215
531204
941231
550413
960311
970405
581231
590519
600402
611210
620331
630721
640108
690930
661231
671210
681231
690816
700106
710905
721221
730329
MAX FOR
620331
END. DATE #D*YS
490329
500906
510324
520224
531216
550101
550425
560318
570412
590102
590525
600407
611216
620412
630727
640112
651009
670106
671213
690105
690823
700111
710908
721225
730401
B
7
B
10
13
2
13
B
B
3
7
6
9
13
7
5
10
7
4
6
8
6
4
3
4
TOTAL PERIOD OF RECORD
620412 13
PERCENTILES
0.05
0.10
0,25
0,50
DAYS
13.0
13.0
8.5
7.0
STATION 168295 SCHRIEVER, LA
AHC* 6.0 DEPLETION RATEiO.75
BEG.GATE END.DATE #DAYS
480301 480317 16
490328 490409 13
500402 500407 6
51(1326 510402 6
520331 520406 7
930716 530720 3
540729 540803 6
950206 550209 4
960930 561008 9
970604 570610 7
580911 580917 7
590530 590612 14
601224 601226 3
610907 610914 8
620109 620112 4
631109 631116 B
641003 641009 7
651216 651223 6
660210 660217 B
170205 670212 8
661230 661231 2
690409 690419 11
701027 701030 4
710907 710911 5
721220 721224 5
730416 730423 B
MAX FOR TOTAL PERIOD OF RECOPD
480301 460317 16
STATION 319191 HEIDDN. NC
AWCi 6.0 DEPLETION RATE»0.75
STATION 445120 LYNCHBURG, V*
*wc« 9.0 DEPLETION
PERCENTILES
0.05
0.10
0.25
0.50
DAYS
15.3
13.3
8.0
7.0
BEG, DATE END. DATE #DAYS
260311
270110
290128
291223
300116
310112
321211
330208
340226
351223
360127
371209
380618
390825
400124
410307
421221
430214
441127
451229
460411
470118
480208
490511
501229
260314
270116
260201
291225
300126
310116
321220
330212
340301
360101
360202
371214
380622
390902
400201
410309
421223
430216
441201
460102
460413
470121
480213
490512
501230
•1AX FOR TOTAL PERIOD C
100116
PERCENTILES
0,05
0,10
0.25
0,50
300126
DAYS
10.7
10.0
7.0
5.0
4
7
5
3
11
5
10
5
4
10
7
6
5
9
V
3
3
3
5
5
3
4
6
2
3
IF RECORD
11
BEG. DATE END. DATE #DAYS
480124
490103
500127
511214
920125
530102
540110
550201
560313
57020J
580206
591219
600302
611227
621209
630118
640209
650130
661223
671228
680123
690120
700117
710113
720201
730126
460202
490106
500202
511221
520131
530106
540118
550207
560316
570212
580220
591220
600314
620103
621215
630129
640213
650205
670101
680117
680126
690123
700124
710205
720210
730203
MAX FOR TOTAL PERIOD
710113
PERCBNTILES
0.05
0.10
0.25
0.50
710205
DAYS
23.0
16.6
10.0
7.5
10
4
7
B
7
5
9
7
4
8
15
3
13
8
7
11
5
7
10
21
4
4
7
24
10
9
OF RECORD
24
Fig. 10 Summary tables showing annual estimated storage days for four stations (EPA-2)
-------
SUMMARY TABLE FROM NCC-EPA-3 PROGRAM
A summary of each winter season examined shows the Freeze Index, its duration and the maxi-
mum storage days computed from the daily listings. Additional information includes the mean
number of storage days, the standard deviation, unbiased third moment about the mean, the co-
efficient of skewness and a list of the thresholds used for each of the elements examined. The
thresholds may be changed to fit individual systems or other special conditions. Storage days
are also computed for recurrence intervals of 5, 10, 25 & 50—years using the Pearson Type III
method. The procedure used to define each day and to compute the coefficient of skewness is
shown below;
C START J
<0.50"
<40°F
PRECIPITATION
>0.50"
SNOW DEPTH
MAXT
>40°F
MINT <25°F
>25°F
LDAYS
FAV DAYS
DECREASE = Q - DP ^ MAX
*~ STOR
GA.N=Q-(DD/2)
STOR
GAIN = Q
UN F DAYS >
where
Q = daily volume
DD = drawdown rate
1. Using the values in the "MAX STOR" column, compute the mean storage days (x) and the
standard deviation (a).
2. Cube the difference between each storage value and the mean (STOR-x)3 and sum algebra-
ically.
3. Compute the unbiased third moment about the mean: a = MS (STOR-x)
4. Compute the coefficient of skewness: C = _§_
5. Enter table with Cs and recurrence interval to find k.
6. Storage days are then equal to x + ka.
Fig. 11 Outline of the procedure used in developing the summary table for EPA—3
shown in Fig. 12
39
-------
USE OF CLIMATIC DATA IN DESIGN OF SOILS TREATMENT SYSTEMS
STA * 485390 LANDER/ WY
HIGH TO LOW FREEZE INDEX
4>
O
DATE
INDX
2154
I860
1704
1397
1337
1286
1230
1136
1075
1035
1010
1005
985
883
879
863
836
822
812
732
733
698
664
560
493
413
BEGIN
721110
481103
611101
671101
351110
391103
631206
311113
541127
711101
581114
681123
621219
561113
641110
491202
731118
651211
6Q1102
521115
701209
371101
301107
661130
691116
531117
END
730410
490314
620316
680218
560315
600317
640328
520325
550326
720215
590315
690315
630317
570207
650328
5Q0214
740225
660307
610308
530306
710307
580320
310319
670306
700404
540331
DUR
151
131
133
109
125
134
112
132
121
106
121
112
88
86
138
74
99
86
126
111
88
139
132
98
139
134
MAX
FA
7
16
14
10
19
39
19
28
27
21
10
12
14
14
17
35
15
23
10
11
16
13
9
15
13
17
MAX
UNF
149
109
103
103
46
98
102
43
59
112
47
29
42
58
24
48
31
45
78
40
44
50
18
25
25
14
MAX
STOR
169,00
128,00
123,50
129,75
109,00
126,50
121,00
106,75
111.00
114,75
123,75
104,25
73,50
101,25
88,00
73,00
90,75
87,25
115,25
102,00
61,50
115,50
77,75
82,00
90,25
78,50
MAX
(STOR-MN)
64.24
23,24
18,74
24,99
4,24
21.74
16,24
1,99
6,24
9,99
Id. 99
-.51
-31,26
-3.51
-16.76
.31.76
-14.01
-17.51
10.49
-2.76
-23,26
10,74
-27.01
-22.76
-14.51
-26.26
TABLE 1 EPA-3 03/13/76
PORI 481101-740430
MAX
(STOR-MN)3
265104
12552
6581
156Q6
76
10275
42(33
8
243
997
6848
0
.30347
-43
.4708
.32036
-2750
.£•369
1154
-21
-12544
1239
-19705
.11790
.3053
.18109
STORAGE DATA N • 26 MEAN • 104.76 SD • 22.45 A • 7984 (STQR-MN)3 . 184249 CS .
AVERAGE INDEX 1026
PERCENTILES
MAX 2154
5X 2Q44
10X 1737
25* 1241
50X 934
THRESHOLDS I 32 ft
.70
151
146
139
134
121
169,00
153,30
128,55
121.50
105,45
RECURRENCE
STOR05 •
STOR10 •
STOR25 •
STOR50 •
122.50
134,69
146,93
156,81
1 DEPTH/
,50 PRECIP/ 1.50 RATE < 25 Fj MIN < 40 F/ MAX
Fift. 12 Summary of 26 winter seasons at Lander, WY from the EPA-3 program (see Figs. 13—18 for the daily listings)
-------
USE OF CLIMATIC DATA IN DESIGN OF SOILS TREATMENT SYSTEMS
STA * 485390 LANDER/ WY
SNOW
YR MO DA MAX MIN MEAN DPTH PPPP FOG DD
48
48 11
48 11
11 01
02
03
48 11 04
48 11 05
48 11 06
48 11
48
48
07
11 08
U 09
48 11 10
48 11
11
11 12
13
14
15
16
48
48 11
48
48
48
48 11
48 11
48 11
48 11
11 17
18
11 19
11 20
48 11
48 11
48 11
46 11
48 11
46
48
48 11
48
48
21
22
23
24
25
11 26
11 27
28
11 29
11 30
60
57
39
38
49
47
30
30
39
37
35
46
53
58
53
48
44
33
27
34
34
35
39
45
35
31
25
39
37
29
30
33
31
24
15
17
13
4
9
21
17
21
28
28
26
21
18
15
10
23
10
4
14
21
14
12
5
4
11
5
45
45
45
31
32
32
22
17
24
29
26
34
41
43
40
3£
31
24
19
29
22
20
27
33
25
22
15
22
24
17
5
4
2
2
2
1
T
T
T
7
9
8
6
4
3
3
3
3
2
2
01
,01
,16
,45
,18
.01
COO
EPA-3
PDRI 481101-740430
DUR OUR
FA FA UNF UNF
13
13
13
-1
0
0
•10
-15
• 8
-3
• 6
2
9
11
8
3
-1
-3
• 13
-3
• 10
•12
-5
1
-7
• 10
• 17
• 10
• 8
• 15
13
26
39
38
38
38
28
13
5
2
-4
-2
7
18
26
29
28
20
7
4
•6
-18
-23
-22
-29
-39
-56
-66
-74
-89
X
X
X
X
X
X
3
2
X
L
L
X
X
X
X
X
X
L
I
X
X
X
X
X
X
X
X
X
X
X
X
X
05/13/76
MAX
STOR
1.00
1.25
1.50
2,50
3.50
4,50
5.50
6,50
7.50
7.00
6.50
6,00
6,25
6,50
7.50
8,50
9,50
10,50
11,50
12,50
13,50
14,50
15,50
16.50
17.50
18,50
19,50
Fig. 13 Listing of daily data from EPA-3 program, Lander, WY, November 1948
-------
USE OF CLIMATIC DATA IN DESIGN OF SOILS TREATMENT SYSTEMS
STA * 485390 LANDER* WY
SNOW
YR MQ DA MAX MIN MEAN DPTH PPPP FOG DO
CDD
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
48
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
33
52
48
40
26
31
24
32
35
40
40
43
34
23
26
23
21
27
34
42
25
22
17
18
3
5
15
32
19
27
23
16
17
38
7
0
8
5
9
3
19
22
29
21
16
10
5
3
7
14
17
6
1
11
0
• 14
-17
• 12
7
3
1
1
25
35
43
24
13
20
15
21
19
30
31
36
26
20
18
14
12
17
24
30
16
12
14
9
•6
-6
2
20
11
14
12
2
1
1
2 .24
3
3
3
2
2
2
2
1
1
1 ,01
1
1
1
1
1
1
1
1
2 ,32
6 ,02 F
6 F
6
5
5
4
3
3
-7
3
11
•8
-19
-12
-17
-11
• 13
•2
-1
4
.4
-12
-14
-18
-20
-15
-8
-2
-16
-20
-18
-23
-38
-38
• 30
-12
-21
-18
-20
-96
-93
-82
-90
-109
-121
-138
-149
-162
-164
-165
-161
-165
-177
-191
-209
-229
-244
-252
-254
-270
-290
-308
-331
-369
-407
-437
-449
-470
-488
-508
SPA.3 05/13/76
PDRI 481101-740430
DUR DUR MAX
FA FA UNF UNF STUR
X 20,50
X 21.50
X 22,50
X 23,50
X 24.50
X 25.50
X 26,50
X 27,50
X 28,50
X 29.50
X 30.50
X 31,50
X 32.50
X 33,50
X 34.50
X 35,50
X 36.50
X 37.50
X 38.50
X 39.50
X 40.50
X 41,50
X 42,50
X 43,50
X 44.50
X 45,50
X 46,50
X 47.50
X 48.50
X 49.50
X 50.50
Fig. 14 Listing of daily data from EPA—3 program, Lander, WY, December 1948
-------
USE Op CLIMATIC DATA IN DESIGN OF SOILS TREATMENT SYSTEMS
STA * 485390 LANDED WY
SNOW
YR MQ DA MAX MIN MEAN DPTH PPPP FQG DO CDD
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
23
21
8
16
25
22
23
30
• 1
-1
7
5
13
35
25
18
6
18
5
.5
7
14
1
-12
-8
2
10
13
2
14
13
3
7
1
1
1
-2
3
-1
-15
-15
-8
-14
0
3
12
-5
-12
-5
-12
-21
-19
0
-23
.31
-31
-25
-16
-7
-15
-8
-7
13
14
5
9
13
10
13
15
-8
-e
-i
-5
7
19
19
7
-3
7
-4
-13
-6
7
-11
-22
-20
-12
-3
3
-7
3
3
3
6
7
9
6
8
7
7
9
10
10
9
9
9
9
9
9
9
9
9
9
10
17
17
17
17
16
19
17
15
15
.10
,21
,05
,07
,11
,09
,07
,04
,02
,24
,26
,22
,14
,03
19
18
27
23
19
22
19
17
40
40
33
37
25
13
13
25
35
25
36
45
3d
25
43
54
52
44
35
29
39
29
29
-527
-545
-572
-595
-614
-636
-655
-672
-712
-752
-785
-822
-847
-860
-873
-898
-933
-958
-994
-1039
-1077
-1102
-1145
-1199
-1251
-1295
-1330
-1359
-1398
-1427
-1456
EPA-3 05/13/76
PDR! 481101-740430
DUR OUR MAX
FA FA UNF UNF STOR
X 31.50
X 52.50
X 53,50
X 54.50
X 55,50
X 56.50
X 57,50
X 58,50
X 59,50
X 60,50
X 61,50
X 62,50
X 63,50
X 64.50
X 65.50
X 66,50
X 67,50
X 6B.50
X 69,50
X 70,50
X 71.50
X 72,50
X 73.50
X 74.50
X 75,50
X 76.50
X 77.50
X 78.50
X 79.50
X 80.50
X 81.50
Fig. 15 Listing of daily data from EPA-3 program, Lander, WY, January 1949
-------
USE OF CLIMATIC DATA IN DESIGN OF SOILS TREATMENT SYSTFMS
STA * 485390 LANCER/ dY
SNOW
YR MQ DA MAX MIN MEAN PPTH PHPP FQG 00
49 02 01
49 02 02
49 02 03
49 02 04
49 02 05
49 02 06
49 02 07 27 9 18 15 ,01
49 02 08
49 02 09
49 02 10
49 02 11 38 6 22 10 ,15
12 6 -16 -5 12 ,23
49 02
49 02
49 02
49 02
49 02
49 02
49 02
49 02
49 02
13
14
15
16
17
18
19
20
49 02 21
49 02 22
49 02 23
49 02 24
49 02 25
49 02 26
49 02 27
49 02 28
.2
-1
2
25
21
25
27
22
30
46
38
6
7
18
32
44
50
49
46
36
42
47
45
37
43
39
38
40
-17
• 19
• 19
• 14
2
•6
9
5
2
11
6
• 16
• 28
•a
1
8
22
32
26
17
21
20
25
15
17
23
19
17
-10
-10
• 9
6
12
10
18
14
16
29
22
-5
-11
5
17
26
36
41
36
27
32
34
35
26
30
31
29
29
15
15
15
15
15
15
15
15
14
10
10
12
12
11
11
10
9
8
6
6
5
5
3
2
2
2
2
2
• 42
• 42
•41
• 26
• 20
•22
• 14
•18
>16
-3
'10
>37
'43
'27
'15
-6
4
9
4
-5
0
2
3
-6
-2
-1
-3
-3
• i4Qb
-1540
-1581
• loc?7
-1627
-1649
• lt>63
-1681
• 1697
• 1700
-1710
-17*7
-1790
-1917
-1632
-U38
-1*34
-1325
•1821
•1826
-mz6
-1824
-1321
-1827
• 1829
-1830
• 1833
• 1836
EPA.3 05/13/76
PORl 481101-740430
DDR OUR MAX
FA FA UNF UNF STUR
X 82.50
X 83.50
X 84.SO
X 85.50
X 86.50
X 87,50
X 88.50
X 89.50
X 90.50
X 91.50
X 92.50
X 93.50
X 94.50
X 95.50
X 96.50
X 97.50
X 98.50
X 99.50
X 100.50
X 101,50
X 102,50
X 103.50
X 104.50
X 105.50
X 106.50
X 107,50
X 108,50
X 109,50
Fig. 16 Listing of daily data from EPA-3 program, Lander, WY, February 1949
-------
USE OF CLIMATIC DATA IN DESIGN QF SOILS TREATMENT SYSTFMS
STA # 465390 UNDER* HY
SNOW
YR HO DA MAX MIN MEAN DPTH PPPP FQG DD
.07
,05
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
49
03
03
03
03
03
03
03
03
03
03
03
03
03
03
"3
03
03
03
03
03
03
03
03
03
03
03
03
01
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
26
29
30
31
43
49
46
36
44
96
40
39
49
32
53
39
51
54
62
57
50
50
37
32
40
41
42
33
29
39
39
IB
25
25
27
18
18
22
25
23
11
13
25
21
27
30
30
25
28
28
20
12
22
20
14
21
18
23
31
37
36
32
31
27
31
32
36
22
33
32
36
41
46
44
38
39
33
26
26
32
31
24
25
29
31
2
1
1
1
1
1
T
T
T
T
T
T
T
T
T
T
7
13
7
4
3
3
4
1
1
.25
1.19
,10
.04
.17
.01
EPA-3
PORI 46U01-74C430
OUR
COO FA FA
X
X
X
X
X
X
I
1 X
L
1 X
L
1 X
L
05/1S/76
-1
5
4
0
-1
-5
-1
0
4
>10
1
0
4
9
14
12
6
7
1
-6
-6
0
-1
-8
-7
-3
-1
-1837
-1832
-1828
-182&
-1&29
-1834
-1835
• 1835
-1831
-18*1
-1840
-1840
-1336
-1827
-1813
-1801
-1795
-1768
-1787
-1793
-1799
-1799
-18QO
-1808
-1815
-1818
-1819
X
X
X
X
X
X
X
X
X
X
X
X
X
X
utjl
JNF
109
1
1
1
MAX
STL*
112^50
m!*/
U5.*75
116.75
117. CO
1 1 8 . C 3
118.25
119.25
119.5?
119. CO
118,50
118.00
117.50
117.00
118.00
119.00
120.00
121.00
122.00
123.00
124.00
125.00
126. CO
Fig. 17 Listing of daily data from EPA-3 program, Lander, WY, March 1949
-------
USE OF CLIMATIC DATA IN DESIGN OP SOILS TREATMENT SYSTEMS
STA * 485390 LANDER/ WV
SNOW
YR MQ DA MAX NZN MEAN DPTH PPPP FOG DO COD FA
49 04 01
49 04 02
49 04 03
49 04 04
49 04 05
49 04 06
49 04 07
49 04 08
49 04 09
49 04 10
49 04 11
49 04 12
49 04 13
49 04 14
49 04 15
49 04 16
49 04
49 04
17
18
19
49 04
49 04 20
49 04 21
49 04 22
49 04 23
49 04 24
49 04 25
49 04 26
49 04 27
49 04 28
49 04 29
49 04 30
FREEZE INDEX
41
46
51
57
60
62
67
58
47
59
73
63
49
39
59
68
64
69
70
60
66
64
75
78
70
65
71
77
69
55
23
22
32
31
32
31
35
37
32
27
34
40
32
29
23
35
37
34
39
38
34
40
41
50
45
42
40
42
42
35
32
34
42
44
46
47
51
48
40
43
54
52
41
34
41
52
51
52
55
49
50
52
58
64
SB
54
56
60
56
45
1
1
T
T
,32
T ,15
T .48
.04
0
2
10
12
14
15
19
16
8
11
22
20
9
2
9
20
19
20
23
17
18
20
26
32
26
22
24
23
24
13
-1819
•1817
• 1807
-1795
-1781
-1766
-1747
-1731
-1723
-1712
-1690
-1670
-1661
-1659
-1650
• 1630
-1611
-1591
-1568
-1551
-1533
-1513
-1487
-1455
-1429
-1407
-1383
-1355
-1331
-1318
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
I860
481103
490314 131
EPA.3 05/13/76
PORI 481101-740430
OUR DUR MAX
FA UNF UNP STOR
X 127.00
X 128,00
II 127.50
127.00
126,50
126,00
125,50
125,00
124.50
124,00
123,50
123.00
122.50
11 X 123.50
L 1 123.75
123,25
122.75
122.23
121.75
121.25
120,75
120,25
119,75
U9.2*
118,75
118.25
117.75
117.25
116.75
16 116.25
16 109 128.00
Fig. 18 Listing of daily data from EPA-3 program, Lander, WY, April 1949
-------
I
1
EST
MAX
STOR
DAYS
Lrt — m
sr —
in n
en n
rj
BJ
•— — — — — ~- CM rv rv
BJ
1,1
i -
in
rj
a
rj
rj
ri
r'l
a
eo
RETURN PERIOD (YEARS)
JQ.ll
Ml M
CfCf B
B"? 7 -
CT C
7C U
c?"7 a .
art . c.
n rx
i£. Id
33. Ll :
:
:....-.-|F
mH
ttH
ill
1 '
#
y
?!
u
y
8
f
1
ii
lit
In
if
in
1
1
Lrt or trit3lrit3Lrtisrijiiifuicsiui EJ
, ' '
i < , • "
§
EXTREME VRLUE HNRLY5I5
YRRIHBLE: MRX 5TDRRGE
LRNDER/ RY
94B-7H
PHRHHETER5 :
RLPHR: 0.BMBB2
Lrt Kf
f- m
^-^
• •"'
L»I is ift ia r- m m
[Dm DI m m m w
Fig. ISA Estimated maximum annual storage days for return periods to 100 years (Gumbel)
-------
STATION
BELLE PLAIIME,1A
OES MOINES»IA
GRINNELL.IA
HAMPTON,IA
INDIANGLA.IA
5-YR ln-YR 25-YP 50-Y"
PERIOD
104.3 112.7 121.9 128.0 11/48-04/73 1.50
98.3 105.8 113.9 119.1 11/48-04/73 1.50
102.1 110.0 118.8 12^.7 11/48-04/73 1.50
121.2 130.6 141.2 148.4 11/49-04/72 1.50
85.b 93.9 103.1 109.2 11/48-04/73 1.50
KEOoAUJUA.lA
.CNOXVILLE.IA
LOGAN.IA
NEWTON*IA
OSCEOLA,IA
77.2 84.9 93.5 99.3 11/48-04/73 1.30
87.4 96.8 1U7.5 114.7 11/49-04/70 1.^0
93.1 105.6 110.6 116.5 11/47-04/73 1.50
97.6 106.9 116.9 12?.5 ll/52~04/72 1.50
79.1 87.3 96.3 1C2.3 11/48-04/67 1.50
OSKALOOoA.IA
SHENANDOAH»IA
WINTERoET.IA
BALTIMORE»MD
BALTIMORE»MD
90.8 99.1 108.3 114.4 11/46-04/73 1.50
75.3 83.3 92.0 97.7 11/48-04/73 1.50
96.5 105.4 115.0 121.2 11/53-04/73 1.50
51.8 57.4 63.4 67.3 H/5O-04/72 1.25
48.8 54.8 61.4 65.7 11/50-04/72 1.33
BALTIMORE.MO
CROSSVILLE.TN
DIVERoON DAM,dY
PAVILLION»WY
43.0 49.9 57.7 63.0 11/50-04/72 1.50
48.3 53.9 60.1 64.3 11/53-04/73 1.50
80.7 88.8 98.0 10^.7 11/48-04/74 1.50
122.5 134.7 148.9 158.8 11/48-04/74 1.50
85.3 92.4 100.1 105.2 11/48-04/74 1.50
RIVERTON.WY
100.2 105.7 111.6 115.5 11/47-04/74 1.50
102.1 110.3 119.5 125.8 11/22-04/47 1.50
Table 4 Estimated storage days for indicated return periods from the EPA-3 program.
Note the effect of changing the drawdown rate (DD) at Baltimore and the per-
iod of record at Riverton.
48
-------
APPENDIX B.
SUPPLEMENTAL INFORMATION
The tables in Figure 42 show the calendar dates in spring (in fall)
after which (before which) threshold temperatures, or lower, may be
expected for nine probability levels. The actual dates of the last
occurrence in spring and the first occurrence in the fall are record-
ed and the number of days between these dates each year is computed.
These periods are defined as the length of the growing season, the
freeze-free period, or simply the number of days between the indicated
threshold temperatures. The number of days from the first freeze in
fall to the last freeze in spring is sometimes referred to as the
dormant period.
This period is not the same as the Freeze Index described in the EPA-1
program which is computed by accumulating the daily differences between
the mean daily temperature and 32° F. The freeze tables described in
the previous paragraph are computed from daily minimum temperatures
instead of the mean temperature. Another difference is that the freeze
tables make no provision for the effect of warmer days that may follow
the first low temperature in the fall, or those that precede the last
one in the spring, while the Freeze Index does.
Hourly observations of surface wind direction and speed, including peak
gusts, are taken routinely at most airport stations. Daily peak gusts
are also reported at many of these stations. A variety of wind summaries
covering 5 to 10 years of record are readily available at the NCC and
can be furnished for the cost of duplication. Caution should be exercised
in using wind summaries, since many of them are prepared for special
applications. Some of these include low ceiling-visibility-wind distributions
or all weather wind graphs for airport master plans (Figure 19) and
extreme wind probabilities for design purposes (Figures 20 and 21) .
Stations in coastal or mountain regions usually have quite different day
and night wind patterns. The wind distribution at the proposed site may
be influenced by local conditions and, therefore, quite different from
that at the nearest reporting station. Special wind equipment might be
installed at the proposed site if conditions warrant; however, analyses
of wind direction and speed should be based on at least five or more
years of record in order to obtain a representative distribution.
49
-------
Thorn [20] has chosen the annual extreme fastest mile wind speed as the
best available measure of wind for design purposes. He found that only
airport or open country wind data could be used because of unknown
surface friction conditions at city office exposures. Figures (20) and
(21) are from Thorn's paper and show the 10-year and 25-year mean recurrence
intervals in miles per hour. The charts are based on 21 years of record;
however, suitable adjustments must be made to the values where experience
indicates the wind speeds in the figures are inadequate. These conditions
can exist where unusual channeling occurs, such as the Santa Ana in
California and the winds along the eastern slopes of the Rockies, especially
in the region of Boulder and Colorado Springs.
Thunderstorms and tropical cyclones generally produce their high winds
during the summer months, while the highest wind speeds in winter are
usually caused by extratropical cyclones. Tropical cyclones are often
accompanied by tornadoes and the effects of a well developed tropical
storm can extend inland for several hundred miles. Tropical storms that
move along the Atlantic coastline in a northeasterly direction can
remain intense systems as far north as Maine. According to Thorn, thunderstorms
account for about one-third of the extreme wind speeds in this country.
Mountain and valley winds move along the axis of a valley [21], blowing
uphill (valley wind) by day and downhill (mountain wind) by night. The
valley wind sets in about one-half hour after sunrise and continues
until about one-half hour before sunset, reaching its greatest strength
at the time of maximum insolation along the slopes. On southerly slopes
it may reach 14 mph, while on the north facing slopes it is barely
noticeable. The mountain wind is due to nocturnal cooling and is somewhat
weaker, reaching perhaps 9 mph on occasion, but it is usually stronger a
few hundred feet above the ground than at the surface. Detailed information
about mixing heights, stability and wind patterns in the upper air are
also available [22]. Additional information of interest to planners may
be found in the literature [23, 24, 25, 26, 27, 28, 29].
Note: The values in Figures 25-27 are roughly equivalent to the
minimum temperatures which have an average return period of
100 years (1%), 33 years (3%) and 20 years (5%).
50
-------
SUPPLEMENTAL INFORMATION
LIST OF FIGURES
Figure Page
19 Annual distribution of surface wind direction 53
and speed, Boothville, LA, May 1971-April 1975,
8 observations per day, all weather conditions
20 Surface wind roses, annual, 1951-60 54
21 Isotach 0.10 quantiles, in miles per hour: annual 55
extreme-mile 30 feet above ground, 10-year mean re-
currence interval (after Thorn)
22 Isotach 0.04 quantiles, in miles per hour: annual 56
extreme-mile 30 feet above ground, 10-year mean re-
currence interval (after Thorn)
23 Normal daily average temperature, January (1941-70) 57
24 Extreme low hourly temperatures during the winter 58
season, with absolute minimums for each state
25 Minimum temperatures colder than indicated 1% of the 59
hours during the winter season
26 Minimum temperatures colder than indicated 3% of the 60
hours during the winter season
27 Minimum temperatures colder than indicated 5% of 61
the hours during the winter season
28 Consecutive 3-hour minimum temperature during the 62
winter season
29 Mean annual number of days minimum temperature 63
32°F and below
30 Mean date of last 32°F temperature in spring 64
31 Mean date of first 32°F temperature in autumn 65
32 Mean annual number of days maximum temperature 66
90°F and above, except 70° F and above in Alaska
33 Mean annual percentage of possible sunshine 67
51
-------
List of Figures (cont'd)
Figure Page
34 Mean annual total hours of sunshine 68
35 Mean annual relative humidity (%) 69
36 Normal annual total precipitation (inches) 70
37 Probable number of days per year that precipitation 71
rates per hour can be expected
38 Mean annual precipitation in millions of gallons of 72
water per square mile, by state climatic divisions
39 Ten year, 24-hour rainfall (inches) 73
40 Twenty-five year, 24-hour rainfall (inches) 74
41 Mean annual total snowfall (inches) 75
42 Climatological Summary for Greenwood, MS, 76
Climatography of the U. S. No. 20
42a. Climatological Summary for Greenwood, MS, 77
Climatography of the U. S. No. 20
42b Climatological Summary for Greenwood, MS, 78
Climatography of the U. S. No. 20
42c Climatological Summary for Greenwood, MS, 79
Climatography of the U. S. No. 20
43 Mean annual class "A" pan evaporation (in inches) 84
44 Mean annual lake evaporation (in inches) 85
45 Mean annual class "A" pan coefficient (%) 86
46 Mean May-October evaporation in percent of annual 87
47 Standard deviation of annual class "A" pan 88
evaporation (in inches)
52
-------
THE WIND ROSE IS A SCALED GRAPHICAL PRESENTATION OF SURFACE WIND DATA IN TERMS OF SPEED
AND DIRECTION. THE RADIAL LINES OF THE DIAGRAM ARE POSITIONED SO THAT AREAS BETWEEN THEM
ARE CENTERED ON THE DIRECTION FROM WHICH THE WINDS ARE REPORTED. THE CONCENTRIC CIRCLES
REPRESENT LIMITS BETWEEN SPEED GROUPS SECTORS. I.E.. 4, 13, 15, 18, 24, 31, 38, AND 39+ MILES PER
HOUR. RADII FOR THESE GROUPS ARE ACCURATELY SCALED TO THE RESPECTIVE SPEEDS. THE SEGMENTS
ENCLOSED BY RADIAL LINES AND CONCENTRIC CIRCLES ON THE DIAGRAM REPRESENT WIND SPEED-DIREC-
TION COMBINATIONS. THE DATA FROM A WIND SUMMARY ARE TRANSFERRED TO THE APPROPRIATE AREA
ON THE DIAGRAM AS A PERCENTAGE OF THE TOTAL OBSERVATIONS EXAMINED.
16.5 % of the winds were less than 4 m.p.h.
based on 11,576 observations
+ indicates less than 0.05
Fig. 19 Annual distribution of surface wind direction and speed, Boothville, LA,
May 1971 - April 1975, 8 observations per day, all weather conditions
53
-------
n
I
source:
Selected Climatic Mapt of the United StatM
NOTE: Based on Hourly
'
PERCENTAGE Observations 1951-60
OF TIME WIND BLE* FROM THE
16 COMPASS POINTS OR »AS CALM
INDICATES LESS THAN 0.5". CALM
25 HOUHLV PXDCINTMtn ZS
Fig. 20 Surface wind roses, annual, 1951 — 60
-------
' n
n
_ North Plttt,
| Dod e City
-^._
S_ J .i—r-ifipOTnitooj
Fig. 21 Isotach 0.10 quantiles, in miles per hour: annual extreme-mile
30 feet above ground, 10-year mean recurrence interval (after Thorn)
-------
'
o
PUERTO aico AM vmcm IJLAKD§
Fig. 22 Isotach 0.04 quantiles, in miles per hour: annual extreme-mile
30 feet above ground, 25-year mean recurrence interval (after Thorn)
-------
•
Fig. 23 Normal daily average temperature (°F) for January (1941-70)
-------
,
This mep wet prepared bv th* Nitional Clrmttic Onler. Aihcvill*. North Caroline from
Kjmineriei of hourly obeervitioni publtthcd bv the U S. Army Mobility Equipment
Hjmmiriti of hourly obMrvetiom publithcd bv the U. S. Army mobility equipment
Rewerch ft Development Center. Coiting and Chemicjl Ljboretorv, Aberdeen Proving
Ground, Mtryltnd. The temperiture extremei for eech rlete were uken from "Weither
Recordi-The Outltindinfl WMther Eventl 1871 -1970". Divid M. Ludlum. Fifilc- •"
tempflrlturei an In degree* Fthrelnhelt.
Courtesy—Federal Highway AdminUtration
THE ISOLINES REPRESENT THE LOWEST HOURLY TEMPERATURES
RECORDED DURING THE YEARS 1950^70 AT ABOUT HO LOCATIONS
THE CIRCLED NUMBERS ARE THE LOWEST TEMPERATURES EVER
RECORDED WITHIN EACH STATE BASED ON RECORDS DATING BACK
TOIB7I.
CAUTION IS ADVISED IN PERFORMING INTERPOLATIONS IN THE
VICINITY OF MOUNTAINS WHERE RAPID TEMPERATURE CHANGES
OFTEN OCCUR IN SHORT DISTANCES.
•nsr
Fig. 24 Extreme low hourly temperatures during the winter season with absolute minimums for each state
-------
••'
'
s prepared hv the National Climatic Center. Asheville. North Carolina frorr
if hourly obiervationi publuhed by the U. S- Army Mobility Equipment
Development Center, Coating and Chemical Laboratory, Aberdeen Provinq
ryland. There « » 99% chance thai the daily minimum temperature will be.
wwr n shown All temperatures are in degree Fahrenheit.
Courtesy—Federal Highway Administration
Fig. 25 Minimum temperatures colder than indicated 1% of the hours during the winter season
-------
I
'
•J'r'WJ II.
~,
"•'• iao- i7i'»
«MI>«)"
i^wV3.7
L>
I7l'l HB* ITT*
'»'.
Thii mip wn prtpcrtd bv trie Nctlonil Climatic Ctntir, Aihtvill«, North Carol mi from
•umnwiti of hourly obwrvitloni publlihtd by '^t U. S. Army Mobility Equiprrwm
Rfttirch & D»v»lopmtnt C«nt0r, Ceiling »ntj Chtmical Laboratory, Aberdttn Proving
Ground. Maryland, Thtr« ii i 97% chance that the daily minimum ttmptratun will be
no lowtr than ihown, All ttmparaturai irt in dtgraa FaHrtnhalt.
Courtesy—Federal Highway Administration
II
ee'oo trot
j^ 8«n Ju«nf^^
X^.J./-
ft-if^H
AL.H-lUd
,.,,,
PVIKTO H1CO ^ YM01H iaLATC.1
Fig. 26 Minimum temperatures colder than indicated 3% of the hours during the winter season
-------
This mail was nrniafd bv the Nationa" Climatic Center, AsheviNe. North Carolina from
summaries of hourly observations iiubluhed by thfl U S Army Mobility Eriuipment
Research & Dpvclonment Center, Coaling and Chemical Laboratory. Aberdeen Provinq
Ground, Mdryland. There is a 95% chance that the daily minimum temperature will be
no lower lhan shown. All temperatures are in degree Farirenheil.
Courtesy—Federal Highway Administration
PUERTO BICQ AND V1RC1H I5LAHU3
Fig. 27 Minimum temperatures colder than indicated 5% of the hours during the winter season
-------
;
i •
*———-i • / Lincoln!
„ I J • V-
5Sw—f^*-—•=-- —\
Thif map w« prepared by the National Climatic Center, Aiheville, North Carolina f
•urnmariM ot hourly obvrvatiom published by lh* U S. Army Mobility Equipment
& Development Onter, Coating and Chemical Laboratory. Aberdeen Proving
Ground, Maryland Th* walum reprpjeni the highest ol the three coldtett
hourly temperatunM during a ?4-hour day. All temperature! are in degree* Fahrenheit
Courte»y—Federal Highway AdminUtration
Fig. 28 Consecutive 3—hour minimum temperature during the winter season
-------
<••
1 •
I'I.
FREEZE (32*F)
OCCURS IN LESS
THAN HALF THE
YEARS ALONG I»-
KXDIATE COAST
OF SOUTHERN THIRD
OF CALIFORNIA AND
IN LOS ANGELES AND
SAX FRANCISCO CITIES
totobue 2J5 \
Fort Yukon
• 232 \
23j F«lrl>.nk« \
HcGrith _-,
^
.Bethel
•
St. P,U1 ,
Cold
ALASKA
0 100 20O 300
HAWAII
0 50 100
Source: Climatic Atlas of the United States
BASED OH PERIOD OF RECORD THROUGH 1964.
utlon should be
nter pointing on
NOTE.--C
used In
this gen rail zed aap.
Sharp ch
number o
below •* v^^u. ... ....... .
distances, due to differ-
ences In altitude, slope
of land, typo of soil ,
vegetative cover, bodies
of water, air drainage,
urban heat effects, etc.
days 32"P and
occur in short
Fig. 29 Mean annual number of days minimum temperature 32°F and below
-------
a
•
FRUZE oc-
cms IN LESS
THAN HALF THE
YEARS ALONG
K COAST
OF SOUTHERN
THIRD OF CALI-
FORNIA AMD IN
LOS ANCILES AND
SAN FRANCISCO
CITIES.
FREEZES OCCUR
OF THIS DOT
LINE IN LESS THAU
f THE YEARS.
HOST Or THIS AREA,
SPRING FREEZES OCCUR
SOUTH OF THIS DOTTED
LINE IN LESS THAN
HALF THE YEARS.
SPRING FREEZES ARE ASSUMED
TO OCCUR BETfELN JANUARY 1
AND JUKE 30.
CAUTION SHOULD BE USED
INTERPOLATING OK THIS CEK-
OtALIZID HAP, SHARP
CHANCES IN THE KEAN DATE
•AV OCCUR IN SHORT DIS-
TANCES, DUE TO DIFFERENCES
IN ALTITUDE, SLOPE OF LAND,
TTPE OF SOIL, VIWETATIVE
COVER, BODIES OF 1AT m , All
DRAINAGE, URBAN HEAT EF-
F1CT8, ETC.
IN HAWAII NO
FREEZES EXCEPT
MOUNTAINS ABOVE 3
TO 4 THOUSAND FIET
HAWAII
o w 100
Source:
Selected Climatic Map* of the United States
SUBJECT DATA BASED OH 2563 STATION RtCORDS
Fig. 30 Mean date of last 32°F temperature in spring
-------
n
QC- 1AM
OIKS IN LESS
THAN HALF THE
YIARS ALONG
IMMEDIATE COAST
or
THIRD Or CALI-
FORNIA AM) III
LOS ANGILE3 AND
SAD FRANCISCO
CITIES.
FALL FRIEZES OCCUR
SOUTH OF THIS DOTTED
IN LESS THAN
HALF TH1 YIAM.
FAU. FltEEZD OCCU«
SOUTH OF THIS DOTT
LIHl I» LBS THAU
1ALF TUX TIARS.
AUTUMN (FALL) FRtlZD ARI
AS8VVXD TO OCCUR BVTWDN
JULT 1 AW DECEMBER 31.
c?
0>
IN HAWAII NO
FRIZZES EXCEPT I*
•OUNTAINS ABOVE 1
TO 4 THOUSAND FEET
HAWAII
CAUTION SHOULD BE USED IX
IKr«FOLATIK) ON THIS GEN-
ERALIZED HAP. SHARP
CHANGES IN THE MEAN DATE
HAT OCCUR IN SHOUT DIS-
TANCES, DUE TO DIFFBtSICES
IN ALTITUDE, SLOPE OF LAKH
TTPE OF SOIL, VBCFTATIYE
COVER, BODIES OF IATBB, AH
DRAINAGE, URBAN REAT EF-
FECTS, ETC.
Source:
Selected Climatic Maps of the United States
ALASIA\A
100 MO
ALL TEAR IN WIT OF
MOUNTAINS, ALSO 0
FREEZES; MANT GLACIERS
Fig. 31 Mean date of first 32°F temperature in autumn
-------
J
•
NOTE. — Caution should be
used In interpolating on
this itnrtUna ««p.
Sharp changes In the mean
nu.ber of 3ty. 90'F and
above may occur in ahort
BAH HUMBER or
TIKPEHATORI
10'T AKD ABOVt
ALASKA ONLY
ences In altitude, slope
of land, type of soil,
vegetative cover, bodies
of water, air drainage,
urban heat eUects, etc.
Source:
Selected Climatic Maps of the United State*
ALASKA
* 70" lesa tha.n once In 2 ygare
BASED ON PERIOD OF RECORD THROUGH 1M4
* 90° lees than once in 3 years
Fig. 32 Mean annual number of days maximum temperature 90°F and above except 70°F and above in Alaska
-------
>•
• I
no™.--iiooniD isoLiira
AM BASED OH DATA ntOH
BLACI-BUn> TTPI SimM
RICOKIBU ra pnioo or
MCOU> THUVGH 1M4.
J Selected Climatic Map* of the United States
Fig. 33 Mean annual percentage of possible sunshine
-------
•
•
Source:
Selected Climatic Map« of the United State*
NOTE --SHOOTHKD ISOLIHE9
BASED ON DATA FROK
BUCK-BULB TYPE SUHSHINI
HECOHDKRS DURING THE
PERIOD 1931-60
Fig. 34 Mean annual total hours of sunshine
-------
Source:
lected Climatic Map» of the United State*
observations for 20 years
or more through 1964.
Fig. 35 Mean annual relative humidity (%)
-------
1
SCALE OF SHADES
INCHES
A ——U-i_ /— _»KAOING
fe£S&?4^
BO" AT «T. '\ V M
AIALEALB \\ \ (
40-YEAR MEAN 'TV \^
CAUTION SHOULD Be USED IN
IKTERPOLATING OH THESE GBTi-
KRALIZ10 MAPS, PARTICULARLY
IN MOUNTAINOUS AREAS.
Fig. 36 Normal annual total precipitation (inches)
-------
STATION NAME
ALABAMA
ANNISTON
BIRMINGHAM
DOTHAN
GAD5DEN
HUNTSVILLE
MOBILE
MONTOOMERY
MUSCLE SHOALS
TUSCALODSA
ARKANSAS
EL DORADO
FAYETTEVILLE
FO*T SMITH
HARRISON
HOT SPRINGS
JONESeCRO
LITTLE ROCK
TEXARKARA
FLORIDA
DAVTONA BEACH
FT. LAUDERDALE
FT. MYERS
GAINESVILLE
JACKSONVILLE
MELBOURNE
MIAMI
ORLANDO
PANAMA CITY
.01..191N
59
74
44
58
74
75
65
60
54
51
40
64
56
50
41
66
61
71
54
61
53
72
51
75
69
44
.20-.49IN
25
28
23
28
29
27
25
28
24
23
27
20
21
24
18
23
23
25
23
23
26
25
25
28
56
21
.JO-.99IN
10
10
10
10
10
14
9
10
10
10
8
7
7
30
9
10
10
11
13
14
13
12
11
15
13
10
Ol.OOIN
2
3
2
2
3
6
3
2
2
3
3
2
1
3
3
3
3
5
e
a
5
5
5
6
5
5
* YEARS
ia
n
10
16
14
14
23
21
14
23
4
24
23
17
20
24
19
25
20
13
15
23
IB
23
25
16
STATION NAME
FLORIDA (CONTINUED)
PENSACDLA
SARASDTA
TALLAHASSEE
TAMPA
K. PALM BEACH
GEORGIA
ALBANY
ATHENS
ATLANTA
AUGUSTA
COLUMBUS
MACQN
MOULTRIE
SAVANNAH
VALDOSTA
LOUISIANA
ALEXANDRIA
BATON ROUGE
LAFAYETTE
LAKE CHARLES
MONROE
NEW ORLEANS
SHSSVEPORT
MISSISSIPPI
LAUREL-HATTIESBURG
MERIDIAN
OXFORD
TUPELO
01-.19IN
78
45
66
62
77
52
72
76
70
70
74
53
72
70
47
61
42
56
41
66
66
52
59
54
48
.20-.49IN ,
25
23
31
24
30
23
28
27
22
27
24
24
25
24
27
25
26
24
22
27
21
27
28
26
25
,50-.9»IN
13
11
16
13
15
8
8
9
a
10
7
10
11
9
12
12
12
12
12
19
9
13
U
9
10
Ol.COIN
s
5
7
5
6
2
2
2
2
4
2
4
4
a
4
5
6
5
3
6
3
5
3
3
2
* YE.
5
12
14
17
24
22
14
23
24
24
24
23
24
2
13
29
20
25
17
10
17
22
24
21
17
Fig. 37 Probable number of days per year that precipitation rates per hour can be expected
-------
!
'
Source: Climatic Atlas of the United States
Fig. 38 Mean annual precipitation in millions of gallons of water per square mile, by state climatic divisions
-------
i
'OAA ATLAS
1-HE 11 WESTERN
NFAU FREQUENCY ATLAS OF THE UNITED ST
Hydrologic Sflrvictf Civilian, U. S. Wwthtf Burciu
Fig. 39 10-year 24-hour rainfall (inches)
-------
• I
I
Source: Technical Paper No. 40
RAINFALL FREQUENCY ATLAS OF THE UNITED STATES
Hydro-logic Sen/ion Division, U. 5. Weather Bureau }
Fig. 40 25-year 24 hour rainfall (inches)
-------
!
•i
Source:
Selected Climatic Maps of the United State*
MEAN SNOWFALL (Inches) - Cont'd
(Selected Stations)
MICH. - HOUGHTON 178
N. Y. _ BOONV1LLE 207
PA. - KANE 107
W. VA._ KUMBRABOW STATE FOREST 126
N. C. - HT. MITCHELL 60
PARKER 47
MAINK - GREENVILLE 111
- MT. WASHINGTON 198
FIRST CONNECTICUT LAKE 172
VT. - SOMERSET 1M
MASS. - WEST CUHMINGTON 85
COHK. - NORFOLK 93
DEAN SNOWFALL (Inch*
(Selected Stit ions)
ALASKA - THOMPSON PASS ABOUT 60O
- RAINIER PARADISE R.S
MT. BAKER LODGE 530
- CRATER LAKE 521
- TAMARACK 445
SODA SPRINGS 398
- ROLAND WEST PORTAL 275
- MARLETTE LAKE 241
- SILVER LAKE BRIGHTON 376
- BRIGHT ANGEL 132
- KINGS HILL 270
SUMMIT 253
- BBCHLER RIVER 285
DOME LAKE 215
- WOLF CREEK PASS 409
SILVER LAKE 265
N. HEX.- RED RIVER 136
CAUTION SHOULD BE USED IN
INTERPOLATING ON THESE GKN-
RRALIZKD HAPS, PARTICULARLY
IN MOUNTAINOUS AREAS.
DATA RASED ON PERIOD OF
RECORD THROUGH 1960.
OW DOES NOT OCCUR
\ 1
Fig. 41 Mean annual total snowfall (inches)
-------
CLIMATOGRAPHY OF THE UNITED STATES NO. 20
Climate of
Greenwood FAA AP,
Mississippi
\
^sj^
NATIONAL OCEANIC AND
ENVI RONMENTAL / N A Tl ON A L C LI M ATIC CENTER
ATMOSPHERIC ADMINISTRATION DATA SERVICE / ASHEVILLE, N.C. APRIL 1975
7
/
Fig. 42 Climatological summary for Greenwood, MS, from the series, "Climatography of the
U. S. No. 20"
•
-------
IATITUOE 133 30
LONGITUDE H90 U
.CLIMATOLOGICAL SUMMARY
MEANS ANB fXT«E"ES FOR PERIOD 1951-1973
GREENHOOD *A» »P» MS
ELEVATION 12$
MONTH
JAN
FEB
MAR
APR
MAY
JUN
JULY
AUG
SEPT
OCT
NOV
DEC
YEAR
TEMPERATURE ( *f 1
MEANS
DAILY
MAXIMUM
53. J
64.8
75.6
BJ.5
40.5
92.*
91.7
86.5
77.5
6*. 6
74.9
DAILY
MINIMUM
35.3
44.2
54.0
61.7
64.2
71.6
70.5
64.7
92.4
4!. 6
93.5
MONTHLY
44.3
!4.5
64.1
72.6
79.8
12.1
81.1
75.1
(.4.9
53.6
64.0
EXTREMES
RECORD
HIGHEST
92
88.
92
100
104*
104*
10!
10?
97*
69
109
«
<
>
7?
6*
72
31
54
54
51
54
54
72
"
1
24
31
15
11
?B
1
30
4
3
1
1UC
30
RECORD
LOWEST
-I
20
32
43
49
13
55
39
27
19
• 4
ct
<
U
>
62
60
73
54
56
67
56
67
52
55
>
<
c
12
5
11
4
3
15
23
29
30
29
FEB
51|03
MEAN NUMHF.H
Oh 1 AYS
MAX.
ll
0
0
0
7
18
23
22
13
2
0
65
)!' AND
BELOW
2
0
0
0
0
0
0
0
0
0
4
MIS.
IB
hi
1*
3
0
0
0
0
0
0
1
6
**
(f AND
BELOW
n
o
n
n
n
0
0
0
n
0
0
PRECIPHAl ION TOTALS (INCHES*
z
<
S
*.72
5.03
5.61
4.30
2. 86
4.65
2.92
3.00
2.56
4.34
5.71
51.14
GREATEST
MONTHLY
12.12
16.8*
10.91
7.64
7.51
11.12
7.69
19.65
10.22
13.20
11.13
CC
<
Ui
>
51
73
64
67
61
63
64
58
70
57
61
sir
19.65J98
GREATEST
DAILY
3.76
6.83
4.64
4.48
3.24
4.24
3.56
8.07
4.10
3.61
6.19
5j
>
73
59
55
SI
62
66
59
64
58
70
57
54
SEP
B.07|58
1
21
12
21
29
30
14
24
16
20
13
13
26
20
SNOW. SI.EE1
z
<
X
.9
.6
.3
.0
.0
.0
.0
.0
.0
.0
.0
.3
2.1
MAXIMUM
MONTHLY
5.9
8.0
4.0
,.0
DC
<
Ul
>-
66
60
63
FEI
60
GREATEST
DEPTH
5.0
8.0
2.0
8.0
a:
<
u
>
62
51
66
6}
FE6
51
I
11
Ul
22
25
1
MEAN NUMBER
OF DAYS
o
7
7
6
7
7
5
6
i
4
4
6
7
7J
u,
g
o
o
3
3
4
4
3
2
3
2
2
2
J
4
"
100 01 MORE
1
1
2
2
1
1
2
1
1
1
1
2
16
* ALSO ON EARLIER DATES
FREEZE PROBABILITIES
TEMP .10
PROBABILITY PF LATER DATF IN SPUING IND/DAl THAN INDICATED
32
28
24
20
3/30
3/23
3/12
2/25
.20
3/25
3/14
2/28
2/16
1/24
.30
3/2?
3/ 7
2/20
2/ 9
.40
3/19
3/ 2
2/13
2/ 3
1/10 12/17
.50
3/17
2/25
It 6
1/28
O/ 0
.60
3/14
2/20
1/30
1/22
01 0
,10
3/11
2/15
1/23
1/15
O/ P
.00
3/ 8
21 B
1/15
I/ 6
O/ 0
,90
3/ 5
1/30
I/ 3
O/ 0
O/ 0
O/ 0 PROBABILITY OF OCCURRENCE OF THRESHULO TEMP IS LESS THAN INDICATED PROBABILITY
TEMP
PROBABILITY r.r EARLIER DATE IN FALL (K3/DA) THAN INDICATED
.10
J2 10/23
28 1"/31
24 11/10
20 11/26
16 12/17
.20
10/28
ll/ 8
11/18
12/ 8
II 4
.30
ll/ 1
11/13
11/24
12/11
.49
ll/ 4
11/16
11/29
12/26
O/ 0
.50
U/ a
11/23
12/ 4
I/ 3
O/ 0
.60
11/11
11/27
12/ 8
1/12
O/ 0
11/14
12/ 2
1/2?
O/ 0
.BO
11/18
12/ B
12/19
2/ 9
01 0
.90
11/23
12/15
12/27
O/ 0
O/ 0
U/ 0 PROBABILITY Of nCTURRFNCE OF THRESHOLD TEMP IS LESS THAN INDICATED PHQHABHITY
PRHBABTLTTY OF LANCER THAN INDICATED FREEZE FRFE PFRIOD *DAVS)
92 252
26 302
24 337
20 >369
16 >365
246 ?4?
291 ?83
324 M*
>365 >365
>365 >365
2S9
276
3n7
353
>3e>5
235
270
300
337
>365
232
263
292
326
>365
>
226
257
317
365
PREC1PITAT10M WITH PROBABILITY EQUAL OR LESS THAN
0.05
0.10
0.20
0.30
0.40
0.50
0.60
0.70
0.60
0.90
0.95
1.20
1.63
2.31
2.91
3.51
4.13
4.84
5.64
6.63
8.47
9.91
1.75
2.19
2.81
3.32
3.81
.32
.66
.49
.29
.53
.65
1.93
?,46
1.27
3.95
4.*1
5.28
4. 04
6.86
7.92
9.75
11.12
?.41
2!91
3.62
4.20
4.74
5.29
5.B8
6.56
7.4i
6.72
9.90
l.?6
U65
?• ?6
2.79
1.11
3.«4
4.44
5.11
5.97
7.46
B.*2
0.2B
0.48
1.87
1.27
1.70
2.16
2.76
1.47
4.45
6.10
7.66
1.14
1.5V
2.24
2.84
3.43
4.06
4.76
5.56
6.62
6.41
9.*i7
0.55
o.m
1.24
1.63
2.03
2.46
2.95
3.53
4.29
5.59
6.69
arr
o.ie
0.36
0.73
1.14
1.60
2.14
2.79
3.63
4.61
6.60
8.76
Ui. I
0.00
Q<*0
1.03
1.45
1 .84
2.25
2.69
3.22
3.84
4.95
9.65
224 216
249 237
276 263
307 J95
>365 360
NC1V
O.R5
1.24
1.67
?.45
3.04
5.H7
4.39
5.23
6.34
8.24
9.63
OEC
1.69
2.41
3.20
3.8B
4.52
5.16
5.92
6.72
7.76
9.56
10.91
MEDIAN PRECIPITATION AHOUKTS (0.50 PROBABILITY LEVEL) IN THIS TABLE DIFFER FROM THE HEANS
SHOtm IN THE ABOVE TABLE BECAUSE OF THE METHOD USED IN MAKING THE COMPUTATIONS. THESE
VALUES HERE DETERMINED FROM THE INCOMPLETE GAMMA DISTRIBUTION WHOSE CURVE HAS BEEN FOUND
TO GIVE BEST FITS TO PRECIPITATION CLIMATOLOGICAL SERIES.
Fig. 42a Climatological summary for Greenwood, MS, from the series, "Climatography of the
U.S. No. 20"
77
-------
ST»TIDN| 22 1627 NAX TEMP
ANNUAL
Tiff
75.9
76.6
77,1
79.4
76.0
71.6N
71.6
74.0
72.5
71,9
74. I
74.0
74.9
79.0
TJ.l
71.1
71.»H
74.0
7J.1
76.6
76.4
74,7H
1126.2 1119.1 1*91.> 1711.0 l»l*.» 2080.9 2123.* 2101.4 1991.4 1771,J 14(3.1 1217.6 1711.«
Y«
31
92
31
34
33
96
37
51
99
60
61
62
61
64
69
66
67
61
69
70
71
72
71
JAN
96.6
61.6
99.6
37.1
91.6
91.3
91.0
49.6
32.7
30.1
41.9
49.1
47.7
91.7
53.7
46.2
34.4
50, 1H
54,6
4*. 5
96.7
60.0
91.9
FEI
31.1
61.7
59.1
64.1
37.9
61.7
62.6
41.1
31.3
30.2
61.3
63.6
39.0
59*0
36.3
34.2
32.9
33.6
60.0
61.6
36.9
Hit
66.1
63. 1
70.2
63.1
69.0
63.7
62.9
37.3
63.9
91.4
69.0
39. »
72.6
66*6
36.2
71,4
37.9
63.3
69,1
71.1
APR
72.1
72.2
71.1
10. 1
71.0
7».0
77.3
74.0
7».S
71.2
72. »
71. 2
77.7
79.6
71.0
'3.0
76.*
71.1
70. IN
NAY
19.4
11.9
13.1
77.0
•6.1
16.4
13.1
13.1
13.1
11. •
11.1
ia.6
14.*
16.1
7«,4
14.6
11.9
11. 6
79.2
JUN
90.1
97.1
97.3
91. *
17.5
•1.6
11.6
II. 1
17.5
90. J
13.7
11.3
91.1
90.0
II. 6
90.*
92.6
90.*
91.0
JUL
93.3
97.9
92.4
97.5
92.3
«4.3
91.5
91.4
91.0
9«,6
11.9
9*. 6
90.0
93,6
II. <
VS. 7
91.4
90.9
90.1
1UC
96.7
94.3
92.7
91. »
91. »
93.4
90.3
90.4
*1,6
90.*
19.1
93.7
91.4
91.4
• 4.9
90.*
91.1
9J.3
II.*
iff
11.3
17.5
90.1
93.0
91.3
II. 1
10.9
13.1
16.4
16.1
15.7
16.4
13.1
15.7
10.1
16.1
11.7
91.2
17.2
OCT
71.9
72.6
• 0.7
71.7
77.6
79.4
69.9
74.9
76.)
77.0
77.0
71.1
14.1
73.3
76,9
76.9
76,9
91.1
71.0
10.9
NBV
59.5
62.1
65.5
64,9
61.5
61.1
61.9
66.5
61.3
65.5
61.1
61.7
66,0
69.3
64,4
64.9
69.0
61.7
61.2
70.1
DEC
59.1
99.0
31.0
96.4
39.7
62.1
59. 5M
90.0
96.0
50.6
54.0
52.3
44.0
59.1
91,0
34.9
61.9
65.1
31.9
33.2
STATION! 22 3627
KIN TEM
YR
51
32
31
94
99
96
97
91
9*
60
61
62
61
64
65
66
67
61
6*
70
71
72
71
JAN K
44.4 41.
19.9 1*.
11.6 41.
14.* 11.
12.2 42.
17.1 46.
11.6 10.
12.9 19.
11.1 11.
29.6 41.
10. B 44.
21.1 10.
31.7 13,
16.1 16. (
11.7 11. (
}7,l 14.
35. 9H 31.
11.0 31.
32.0 34.
17.2 37.,
40.4 39.'
33.1 34.
1 Nil 1
1 41.9 49
41,6 37
46,4 37
41. a 92
41.2 55
41.1 91
42.0 92
16.1 94
49.* 49
1 41.3 91
1 47.1 91
> 41.2 97
> 19.1 37
) 44.1 34
) 47.6 3|
> 43.6 S3
> 39.6 36
1 43.6 91
41.1 31
> 43.7 94
90.0 49
PR
.4
,4
.2
.0
,0
,2
,1
.1
.6
.4
.1
,4
,5
.}
,1
.7
,5
• 0
.1
.1
,9N
NAY
39,2
60.1
57. »
64,0
69,0
61.0
ll:l
51.9
31. t
64,*
62,7
61.4
65,1
60.1
39,6
61,7
62,1
61.3
31,1
60,*
37.3
JUN
70.2
72.1
69.6
64.4
61.1
70.9
69.9
61.9
69.0
66.5
69.5
70.2
70.5
69.1
67.1
61.9
61.9
61.1
61.6
70.4
67.4
67.1
JUL
73.2
71,*
71.4
72,7
71.5
71,6
72.7
71.1
72,1
70.2
71,2
71,2
71.3
72.4
71.7
69.1
6*. 7
71,2
70,1
71.7
70.0
71.6
AUC
72.1
71.1
71.1
70.9
69. »
69.5
70.1
72.1
72.2
61.1
71.9
71.5
71.2
71.1
69,1
67,2
70.5
61.6
71.1
71.1
69,*
66,7
SEP
64,|
60.4
60* *
64,4
69.6
99.1
69.2
67.6
66.2
66,1
64.7
63.9
61.7
64.9
67.0
61.7
39.7
61.4
61.1
67.1
11.9
6*. 3
66.1
OC
52.
39.
50.
54.
41.
34.
51.
52.
3T.
39.
90.
97.
94.
41.
91.
41.
41.
91.
94.
91.
31.
99.
96.
r NOV
11.1
40.7
17.9
J9.9
40,0
40.4
49.9
44.5
31.1
41.1
44.9
41.2
44.9
46.1
49.1
46.1
19.2
44.1
40.0
41.2
42.6
42.4
41.9
DEC
41.1
16.1
13.9
13. i
17.1
44.1
40.1
12.1
11.6
11.2
17.9
14.0
27.6
19.4
11.4
17.7
40.4
16.0
15.7
40,0
41.1
91.1
15.1
•12.9 169.4 1016.0 1242.1 1411.4 1990.4 1630.9 1621.0 1417.6 1204.3
ANNUAL
91,9
92.9
91,4
94,0
91.1
91,6
99.ON
92.9
91.7
92,6
92.7
54.0
91.9
91.7
34,6
31.0
32,4
52,7N
51.2
91,4
94.7
94.9
91.IN
162.2 1229.6
STATIONl 22 3627
•VEIUGE TEHPE««TU«fc
YR
51
52
51
54
55
96
57
51
59
60
61
62
61
67
61
6*
70
71
72
71
ANNUAL
64.7
64.4
61,0
65,7
64,4
64,1
64.IN
62.1
61.9
62.6
61.1
64.1
61.1
64.1
64.1
61.1
61.7
61.IH
61.6
64.1
69.7
69.3
64.ON
1020.0 1094.» 1294.1 1490.» 1669.7 1116.4 1«!»,0 1163.4 1743.6 1491.1 12)1.0 1079.9 1471,1
JAN
46.1
91.0
49.1
47.9
44.3
41.1
49.2
40.6
42.6
44.9
39.3
40.0
11.0
41.7
46.1
19.0
49.1
42. IN
46,1
40,1
47.0
30.2
44.1
FES
41.4
92. *
49.1
91.1
41.2
92.1
54.6
39.1
49.1
42.1
51.1
35.0
41.1
41.1
46.6
46.4
41.5
40.1
47,0
45.4
41.6
30.5
45.9
NAP.
36. •
51. T
60.1
94.7
97.7
94.4
91.1
49.7
34.0
45.1
59.9
50.5
60.2
54.9
41.0
95.*
99.3
53.3
*«.»
93.2
52.6
97.9
60.*
APR
62.0
60.1
61.1
41.1
67.6
61.0
66.1
61.6
61.1
66.5
61.0
62.1
67.5
67.2
61.5
64.1
61.1
64.7
69.1
67.7
61.*
66.2
59. »N
NAV
72.1
72.1
74.1
67.1
79.2
75.7
71.4
73.2
79.7
70.4
70.0
76.1
79.1
74.0
76.0
71.3
69.0
70.6
71.4
74,0
69.1
72.3
61.4
JUtt
10.2
14.7
19.7
• 1.1
76.0
71.4
79.1
79.4
71.2
79.7
76.1
79.0
10.7
• 1.2
79.6
71.1
71.1
79.1
79.9
79,7
• 1.5
7V. 2
79.4
JUL
19.1
14.7
II. 4
15,9
11,5
11.0
11,6
12,1
11.2
13.4
79.6
19.9
10.6
11. 1
11.0
14.6
71.0
79.0
14,9
10.*
11,6
10.9
11.2
AUS
• 4.1
•1.2
• 1.0
•».»
• 1.1
•1.7
10.0
10.4
12.0
11.6
79.2
• 2.1
• 1.9
10.7
11.4
79.4
75.*
7*. 6
7*. 7
• 1.1
• 1.1
11.7
77.1
SEP
76.6
74.0
7».l
76.7
71.5
74.1
71.1
76.5
76.1
76.2
75.2
76.2
74,4
79.*
76.4
71,9
69. 9
72.1
74.6
79.1
7B.I
10.1
77.0
OCT
63.9
96.1
69.6
66.4
61.2
66.9
60.6
61.6
66.1
66.0
61.9
67.1
69.7
61.2
61.1
61.1
61.1
69.0
69.1
64.1
71.1
66.9
61.7
NOV
41.1
51.1
51.6
52.2
31. •
52.1
51.9
51.5
49.7
51.4
51.4
92.5
59.1
96.1
99.6
36.7
51.1
53.3
52.5
31.1
95.7
91.1
99.9
DEC
90.3
43.1
41.5
45.1
46.4
51.9
49.91
41.4
47.)
41.9
46.0
41.1
35.1
41.4
41.9
49.7
4*.l
49.1
49.1
91.0
96.6
41.7
45.4
Fig. 42b Climatological summary for Greenwood, MS, from the series. "Climatography of
the US. No. 20"
78
-------
STATION! 22 9627
TOTAL PRECIPITATION
Y»
51
52
53
54
55
56
57
58
59
60
61
62
63
6*
65
66
67
61
69
70
71
72
73
SUN
SEASON
50-51
51-52
52-53
53-54
54-55
55-16
56-J7
57-S«
58-59
59-60
60-61
61-62
62-63
63-64
64-65
65-66
66-67
67-68
68-69
69-70
70-71
71-72
72-73
73-74
JAN
12.12
J.«o
4.01
6.14
4.11
2.55
1.4]
2,84
1.71
6.60
1.21
}.»«
2.26
3.49
1.78
5.17
1.52
8.06
4.23
1.67
3.25
8.25
9.25
108.47
STATION!
JUL
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
FEB
1.66
3.00
7.70
2.98
4.95
10.42
1.76
3.16
6.47
3.52
1.56
4. S3
2.66
3.33
6.50
7.95
4.90
2.30
3.13
3.34
4.66
1.21
3.10
106.11
22 3627
AUC
.0
.0
-.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
.0
HA* APR
e.ze <
5.12
6.16
2.04
8.37
4.60
5.15
4. as
3.41
5.61
10.10
3.32
4.95
6.71 1
6.95
1.06
2.54
4.69
4.62
6.74
5.25
6.00
.27
.61
.31
.68
.09
.39
.69
.90
.51
.48
.4V
.16
.53
.91
.11
.31
.00
.23
.48
.28
.37
.98
16.14 .46
134.06 129.04
S6P DCT
.0 .0
.0 .0
.0 .0
.0 .0
.0 .0
.0 .0
.0 .0
.0 .0
.0 .0
.0 .0
.0 .0
.0 .0
,0 .0
.0 .0
.0 .0
.0 .0
.0 .0
.0 .0
.0 .0
.0 .0
.0 .0
.11 .0
.0 .0
HAY
.*2
4,91
5.95
7,11
3.46
2,64
3,47
7,12
6,06
1,06
1.13
5,45
1.45
1.15
1.76
2,«S
7,69
6.56
2.73
2.24
5.26
4.62
7,05
96, 9B
NOV
T
.0
.0
.0
,0
,0
.0
.0
.0
.0
.0
,0
.0
.0
.0
T
T
.0
.0
.0
T
.0
,0
JJN
6.6«
.94
.22
.56
2.13
1,34
4.94
4.11
2.73
1.6B
7.58
4.69
2,28
1.16
.88
4.64
2.89
2.12
1.18
i.ie
5.38
3.35
• 1]
65. Tl
TOTAL
Dec
T
.0
r
.0
.0
.0
.0
2.0
T
T
.0
T
4.0
T
.0
T
1.0
T
.0
.0
.0
.0
T
JUL
4.71
1.34
3.75
2.09
4.2»
3.67
2.9>
9.31
8.16
1.74
7.34
1.22
11.12
1.02
2.02
1.B6
2.30
4.11
4.00
4.55
7.68
4. BO
10.95
106.93
SNOtlPALL
JAN
2.7
.0
T
T
T
T
,0
1.0
T
• 0
T
5,0
T
,5
T
3.9
.4
1,0
.0
T
4,0
.0
T
AUC SEP OCT
1.39 3.94 2.91 2
*.!» 1.06 T 1
•73 1.10 .63 1
1.19 .82 .19 3
•B9 .54 .23 1
.70 .16 .90 4
2.74 3.48 .07 13
2.55 19.63 .91 I
*.31 1.21 .49 2
7.60 3.11 .50 4
2.25 1.20 .16 11
1.34 4.91 ,82 4
1,41 .46 ,00 3
7.69 1.19 .02 4
2-78 2.92 .64 I
1.17 4,77 .89 1
1.1B .80 ,00 2
4.04 5.96 ,66 7
4.52 1.38 .44 2
1.42 1.35 10.22 I
4.31 1.20 1,46 1
3.66 1.22 3,18 8
•50 .44 4,11 6
67,19 69.09 58.81 99
FEB MAR APR
5.0 T .0
.1 T .0
.0 T .0
.0 .0 .0
.0 .0 .0
.0 .0 ,0
.0 T .0
T ,0 .0
.0 ,0 .0
B.O T .0
T .0 .0
.0 .0 ,0
T .0 .0
.0 .0 .0
.1 T .0
T .0 .0
T T .0
.5 6.0 .0
.1 T .0
T .0 .0
7 T T
1 .0 .0
.0 .0 .0
NOV DEC
.61 10.24
.80 .51
.05
.70
.76
.43
.20
.76
.91
.27
.69 1
.77
.12
.75
.04
.30
.76 1
.92
.63
.39
.30
,40
.99
,86
,44
.12
.72
.48
.97
.30
.38
.13
.67
.50
.91
.91
.24
,73
.40
.77
.71
• 96
.63
.85
.77 131.41
MAY JUN
.0 .0
.0 .0
T .0
.0 .0
.0 .0
.0 .0
.0 ,0
.0 .0
.0 .0
.0 .0
.0 .0
.0 ,0
• 0 .0
.0 ,0
.0 .0
.0 .0
.0 ,0
.0 ,0
.0 ,0
.0 .0
.0 .0
.0 .0
.0 .0
ANNUAL
61.63
19.39
46.49
42.34
42.70
47.72
62.04
66.13
50.93
46.55
66.91
48.78
17.78
91.73
12.11
42,19
45,51
62,07
48,31
53.29
52.08
37,70
74,07
1176.29
SEASON
,3
.0
.0
.0
,0
,0
1,0
2.0
•.a
.0
5,0
,0
4.
•
5.
,
>,
.
.0
4.0
.0
.0
7.0
20.3
14,7
E AHOUNT IS WHOLLY OK PARTLY ESTIMATED.
T TRACE' AN AMOUNT TOO SHALL TO KEASUM.
H ONE OK MORE DAYS Or RECORD MtSStNCl IF AVERAGE VALUE IS ENTEREP, LESS THAN 10 DAvS RECORD IS HISSING,
0 HATE* EQUIVALENT OF SNOWFALL HMOI L» OR PARTLY ESTIMATED.
MONTHLY NOBHALS CF TEHPERATURE, PRECIPITAT1DN AND HEATING A«D COOLING DECREE OAYS (1941-70)
JAN FEB *AR APR HAY JUt, JUl AUG SEP OCT NOV DEC ANN
TEMPERATURE 44.6 47.B 54.5 65.1 72.B 79,9 82,0 81.2 75.1 64.8 39,9 46.3 64.0
PRECIPITATION 4.87 5.06 5.63 5.15 4.31 3.31 4.1* 2.99 3.2* 2.56 4.5B 5.26 SI.32
HEATING DEGREE DAY 632 4m 353 77 9 0 0 0 0 109 349 580 2398
COOLING DECREE DAY 0 8 .28 80 251 447 327 502 306 103 0 0 2Z3Z
Fig. 42c Climatological summary for Greenwood, MS, from the series, "Climatography of
the U.S. No. 20
79
-------
EVAPORATION MAPS FOR THE UNITED STATES
Hydrologic Investigations Section, Hydrologic Services Division,
U. S. Weather Bureau, Washington, D. C.
Since evaporation inevitably extracts a portion of the gross
water supply to a reservoir, the estimation of this loss is an
important factor in reservoir design. In arid regions, the evap-
poration loss actually imposes a ceiling on the water supply ob-
tainable through regulation. Speaking of storage on the main stem
of the Colorado River, Langbein [30] states that "The gain in
regulation to be achieved by increasing the present 29 million acre-
feet to nearly 50 million acre-feet of capacity appears to be largely
offset by a corresponding increase in evaporation."
In the final stages, the design of major storage projects re-
quires detailed study of all data available, including observations
made at the proposed reservoir sites. However, generalized esti-
mates of free-water evaporation are invaluable in preliminary design
studies of major projects, and are often fully adequate for the
design of lesser projects. The maps presented herein have been
prepared to serve these purposes, primarily, but they should be
of value in other studies. For example, free-water evaporation
[Figure 44] is a good index to potential evapotranspiration, or
consumptive use, and the pan coefficient [Figure 45] is indicative
of an aspect of climate. If solar radiation, wind, dew point, and
air temperature are such that water in an exposed Class A pan is
warmer than the air, the coefficient is greater than 0.7, and vice
versa.
In 1942, A. F. Meyer [31] published a map comparable to that
in Figure 44, and in the following year R. E. Horton [32] published
a map of Class A pan evaporation similar to Figure 43. Subsequent
to 1942, there has been a substantial increase in the Class A pan
station network and significant progress in the development of
techniques for estimating lake evaporation. However, the maps
prepared by Horton and Meyer were carefully studied in the prep-
aration of the new series — any pronounced differences are
considered to be reasonably substantiated by data now available.
Figure 45 shows the ratio of annual lake evaporation to that
from the Class A pan. It can be used to estimate free-water evap-
oration for any site for which representative pan data are available.
Figure 46 has been included to assist in the extrapolation of
seasonal pan evaporation data to annual values, as well as to
provide an indication of the seasonal distribution of evaporation
from a shallow free-water body. Figure 47 shows the variability
of pan evaporation, year-to-year, and can be used to estimate the
frequency distribution of annual lake evaporation. The correct
interpretation and use of these plates are discussed later.
80
-------
METHODS FOR COMPUTING EVAPORATION - - The various methods for com-
puting pan and lake evaporation are described in the Lake Hefner [33] and
Lake Mead [34] Water-Loss Investigations Reports, and in Weather Bureau
Research Paper No. 38 [35]. There are four generally accepted methods of
computing lake evaporation: (a) water budget, (b) energy budget, (c) mass
transfer, and (d) lake-to-pan relations. Very few reliable water-budget
estimates are available because small errors in volume of inflow and out-
flow usually result in large errors in the residual evaporation value.
The energy-budget approach requires such elaborate instrumentation that
it is only feasible for special investigations. The mass-transfer method
requires observations of lake surface-water temperature, dew point, and
wind movement which are available for only a very few reservoirs. Methods
(a), (b), and (c) are only applicable for existing lakes and reservoirs,
and cannot be used in the design phase.
The few lake-evaporation determinations that have been made using
water-budget, energy-budget, and mass-transfer methods were used in pre-
paring Figs. 44-45. However, from a practical point of view, the lake-
evaporation map -is based essentially on pan evaporation and related met-
eorological data collected at Class A evaporation and first-order synoptic
stations.
DEVELOPMENT OF MAPS The description of the development of the
maps is given in Weather Bureau Technical Paper No. 37 "Evaporation Maps
for the United States."
INTERPRETATION, USE, AND LIMITATIONS OF MAPS Although the utility
of the derived maps hinges largely on their reliability, it is virtually
impossible to make any meaningful generalizations in this respect. In
deriving Figures 43-45, all available pertinent data were utilized to
the greatest extent feasible with present-day knowledge of the relation-
ships involved. It can be reasonably assumed, therefore, that the maps
provide the most accurate generalized estimates yet available. The re-
liability of the maps is obviously poorer in the areas of high relief than
in the plains region, and the density of the observation network is an
important factor throughout.
It is known that some of the data collected over the years are from
sheltered sites which are not representative. Through subjective evalua-
tion of the station descriptions and wind data, an attempt was made to
derive pan evaporation and coefficient maps indicative of a representative
exposure, reasonably free of obstructions to wind and sunshine. Variations
in the data were smoothed to a considerable extent, and it is entirely
possible that the true areal variation in evaporation exceeds that shown
on the maps. For example, a pan or small reservoir located in a canyon
of northerly orientation and partially shielded from the sun would ex-
perience considerably less evaporation than indicated by the maps.
81
-------
The effect of topography has been taken into account only in a general
way, except where the data provided definite indications. Thus, it will be
noted that the isopleths tend to follow closely the topographic features in
some portions of the maps while the resemblance is more casual in other areas.
Both Class A pan and lake evaporation were assumed to decrease with elevation
however, the decrease assumed for lake evaporation is less. With an
increase in elevation, dew point and air temperatures tend to decrease, while
wind movement usually increases. Solar radiation, on the other hand, increases
upslope during cloudless days and may otherwise increase or decrease depending
on the variation of cloudiness with elevation. There are but few reliable ob-
servations of the variation of all these factors up mountain slopes, but it is
probable that the effect of these changes is less for lake evaporation than
for pan evaporation.
There is good reason to expect that Figure 46, showing seasonal distribution
of pan evaporation, is more reliable than any other map in the series. Fig. 47,
on the other hand, is based on a sparse network, and time trends resulting from
changes in site, exposure, etc., may have caused some bias in the derived
values of standard deviation. Data which were obviously inconsistent were
eliminated from the analysis, but any undetected inconsistencies result in
values which tend to be too high. Even so, any bias in the final, smoothed
isopleths should be small.
The use of Figs. 43-47 is self-evident in most respects and need not be
considered further here. Certain limitations and less obvious features are
discussed in the following paragraphs.
Figs. 43, 44 and 45. Unless the user has at hand pan-evaporation data not
considered in the development of this series of maps, average annual lake evap-
oration can be taken directly from Figure 44. The value so determined will also
suffice if pan-evaporation data collected at the site substantiate that given
by Figure 43. If the pan evaporation at the site exceeds that given by Fig. 43,
application of the pan coefficient (Figure 45) will probably provide a better
estimate of lake evaporation than that given by Figure 44. If, on the other
hand, observed pan evaporation is less than that given by Figure 43, a value of
lake evaporation less than given by Figure 44 should be accepted only after it
has been determined that the pan site is reasonably free of obstructions to
wind and sunshine. This is to say that pan evaporation and the pan coefficient
are both dependent upon exposure.
It should be emphasized that values of free-water evaporation given by
Fig. 44 (or Figs. 43 and 45) assume that there is no net advection (heat content
of inflow less outflow) over a long period of time. The mean annual advection
is usually small and can be neglected, but this is not always the case. It was
found at Lake Mead, for example, that advection results in a 5-inch increase in
mean annual evaporation. If the advection term is appreciable, adjustment
should be made as discussed in references [34] and [35].
82
-------
Figure 46. The Class A pans are not in operation during the winter
months over much of the country because of freezing weather. Fig. 46 provides means
of estimating average annual evaporation from that observed during the open
season, May through October. When used in conjunction with Fig. 43, it also
provides a means of estimating average growing-season evaporation (Class A pan)
which is so important in some studies.
Although the seasonal ratios of Fig. 46 are based on Class A pan
data, it is believed that they are equally applicable to free-water
evaporation for shallow lakes. The ratios based on monthly computed
lake evaporation for the first-order stations showed no significant
deviation from those based on the pan values. It should be emphasized
that the seasonal ratios can be applied to annual lake evaporation only
in case of shallow lakes where energy storage can be ignored. In deep
lakes, the energy storage becomes an important factor in determining
seasonal or monthly evaporation. For example, at Lake Mead the maximum
lake evaporation occurs in August, but maximum Class A pan evaporation
is observed in June; for Lake Ontario, the maximum lake evaporation is
in September, and maximum pan evaporation in July. Corrections can
be made for changes in energy storage and heat advection into or out of
the lake in the manner described in references [34] and [35].
Figure 47. The standard deviation of annual Class A pan evaporation
can be obtained for any selected site directly from Fig. 47. If the
annual pan coefficient were constant, year-to-year, then the standard
deviation of lake evaporation would be the product of that for pan evap-
oration and the pan coefficient. Because of variation in the annual pan
coefficient, the standard deviation computed in this manner may be a
few percent too low. Since the values given by Figure 47 are probably
biased on the high side (discussed previously), the two possible errors
tend to compensate.
Having obtained the mean and standard deviation, the frequency
distribution of annual lake (or pan) evaporation can be derived, assuming
the data are normally distributed. If it is further assumed that the
annual evaporation totals occurring in successive years are independent,
the frequency distribution of n-year evaporation can also be derived.
83
-------
00
1
EVAPORATION MAPS FOR THE UNITED STATES
Hydrologic Investigations Section, Hydrologic Services Division,
U. S. Weather Bureau, Washington, D. C.
^^ ._i. -\-&\ i H i ra
JT i" ^L L L ' | I ' ir J.
Fig. 43 Mean annual class A pan evaporation (in inches)
-------
EVAPORATION MAPS FOR THE UNITED STATES
Hydrologic Investigations Section, Hydrologic Services Division
U. S. Weather Bureau, Washington, D. C.
'^-A :Hii=L
Based on period 1946-55
Fig. 44 Mean annual take evaporation (in inches)
-------
•
.
EVAPORATION MAPS FOR THE UNITED STATES
Hydrologic Investigations Section, Hydrologic Services Division,
U. S. Weather Bureau, Washington, D. C.
IS
Fig. 45 Mean annual class A pan coefficient (in percent)
-------
EVAPORATION MAPS FOR THE UNITED STATES
Hydrologic Investigations Section, Hydrologic Services Division
U. S. Weather Bureau, Washington, D. C.
1 .*«"''"\ III I I..",!
ir I-' L I n U^^i
Fig. 46 Mean May—October evaporation in percent of annual
-------
•
/Source:
EVAPORATION MAPS FOR THE UNITED STATES
Hydrologic Investigations Section, Hydrologic Services Division,
U. S. Weather Bureau, Washington, D. C.
I ' V |J 1. ^ i-
V \\ 7, 3 Slondord d.
-•*' • Slondord dtmolion band on annual »aluti ulimond from obltrvid doig
7,,r/ Y.off of r.co-d u..d .
i ol llondord d.
' —if
Fig. 47 Standard deviation of annual class A pan evaporation (in inches)
-------
APPENDIX C.
REQUESTS FOR SERVICES
The National Climatic Center may furnish special services for private
clients under authority of an Act of Congress which permits the NCC to
provide services at the expense of the requester. The amount the re-
quester is charged in all cases is intended solely to defray the expenses
incurred by the Government in satisfying his specific requirements to the
best of its ability.
Unit costs have been established for reproduction or processing of data.
The product can be in various forms, such as copies of microfilm,
magnetic tapes, computer output in the form of tabulations, or other
types of material. In the case of the programs discussed in this
report, the station record must be serially complete and readily avail-
able in the NCC tape library. A day or two of missing record during a
month is acceptable over the 20 to 25 year record, but care must be
exercised to avoid processing stations with excessive missing record.
Upon establishing that an adequate data base exists and costs agreed on,
authorization for the NCC to proceed with the work may be made by letter
or telephone. A copy of the product will be forwarded, usually within 3
to 4 weeks, along with an invoice. No advance payment is necessary,
although private users who have a continuing need for climatological
services may make advance deposits to cover the cost of their require-
ments as they arise. This procedure eliminates the need for separate
invoices upon completion of each request. Further information about the
programs may be obtained by contacting the Statistical Climatology
Branch, National Climatic Center, Federal Building, Asheville, North
Carolina 28801 (telephone 704-258-2850, ext. 319).
89
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-600/2-76-250
2.
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
USE OF CLIMATIC DATA IN ESTIMATING STORAGE DAYS FOR
SOILS TREATMENT SYSTEMS
5. REPORT DATE
November 1976
(Issuing date)
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Dick M. Whiting
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Robert S. Kerr Environmental Research Laboratory
Post Office Box 1198
Ada, Oklahoma 74820
10. PROGRAM ELEMENT NO.
1BC611
11. CONTRACT/GRANT NO.
EPA-IAG-D5-F694
12. SPONSORING AGENCY NAME AND ADDRESS
Robert S. Kerr Environmental Research Laboratory
Office of Research and Development
U. S. Environmental Protection Agency
Ada, Oklahoma 74820
13. TYPE OF REPORT AND PERIOD COVERED
Final 4/75 to 7/76
14. SPONSORING AGENCY CODE
EPA-ORD
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Computer programs have been developed to estimate storage needs for Soil Treatment
Systems from analyses of daily climatological data. One program uses a set of
thresholds for temperature, precipitation and/or snow depth to estimate storage
needs in colder regions.
A second program is designed for use in high rainfall regions where saturated soil,
rather than severe weather, is the limiting condition. Climatological data for a
20- to 25-year period is examined for each case to produce a summary table. This
table presents the mean, the standard deviation, the unbiased third moment about
the mean, the coefficient of skewness and storage days for recurrence intervals of
5, 10, 25, and 50 years.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Climatology
Effluents
Cold-weather operations
Land application
Estimating storage
4B
2C
13. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport)
UNCLASSIFIED
21. NO. OF PAGES
98
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
90
U. S. GOVERNMENT PRINTING OFFICE: 1977-757-056/5AA7 Region No. 5-11
------- |