WMOD00057

• Contract/Permit #: #90-3
• Applicant: Western Kansas Groundwater
• Project Name: Kansas Weather Modification
• Date: 9/13/1990
• Weather Modification - Doc Type: Report

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The \l1{'WX Program, under the guidance of Groundwater Management
District #1 (Scott City), sustains a cooperative rainfall reporting
effort of over 100 area individuals. These observers record daily
rainfall amounts and send in their observations each month for
tabulation by the WKWK Program. What follows on the two subsequent
pages 1s the total rainfall received for the months May through
August of 1990 (Figure 7) and the rainfall departure from Dormal
(Figure. 8), The rainfall departure is based on the official county
long-term average rainfall 1941-1970---prior to the establishment
of the weather modification program. There is a small shortcoming
with the rainfall data analyzed this summer, Some i~PQrtant data
have not yet been received for tabulating and analysis as of the
writing of this report. Hence, the rainfall analyses in Figures 7
and 8 lack some of the specific detail we would normally like to
have. [n any case the analyse$ are probably representative enough
for our purposes in showing areal tendencies of rainfall.

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Figure 7 shows a rainfall maximum in portiDns Df the cDunties
of Haskellt Grant, KearnYt Finney, Gray, Stanton and Hamilton
centered over the Haskell-Grant county line. TWQ other areas Df
maximum rainfall appear: <i) Scott) Lane and HE Finney, and (2) NE
Ford County. There 1s a good reason for the Haskell-Grant rainfall
maximum to appear there: In past years we have noted the high
correlation of high rainfall to high hail frequency because
extremely severe storms usually produce the highest rainfall
amounts or that a number of moderately severe storms may exhibit a
tendency to pass over one area more than ather areas. If we look
back at Figure 5 showing the total number of hail instances for
each of the counties of Kansas, we see a track, or region, where
hail claims tend to be higher than nearby counties; they are seen
in an area aver Hamilton, Stanton, Grant, Haskell and Gray.

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Similarly, the northeast portion of the target area in Lane
and Scott counties had extremely severe storms pass NW-SE across
them several times this summer producing extensive hail damage as
well. Although we do not have rainfall observers further north
than Gave County I there appeared to be a tendency fDr rainfall to
increase north, nDrtheast and east af Lane County which ties in
with hail claim maximums over Sheridan and Ness counties. Those
two counties had the highest and second highest number of hail
claims in the state this year, respectively.

Figure 7 also shows important relative minimums over: (1) a
fairly extensive area in Gray and Ford counties, and (2) the
Greeley County-Wallace CDunty area. Also, it 1s interesting to
note that rainfall drops off dramatically south of Haskell County
proceeding in the direction of Oklahoma. This helps confirm the
NOAA/USDA DrDught Severity Index discussed earlier that shows a
lack of crop moisture in Oklahoma.

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