WMOD00234

• Contract/Permit #: #93-5
• Applicant: Western Kansas Groundwater
• Project Name: Kansas Weather Modification
• Date: 1/1/1993
• Weather Modification - Doc Type: Report

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Each year is different from the next, weatherwise. In 1992 it
may be recalled that growing season temperatures were cooler than
normal and moisture, with minor exceptions, was well above normal
in our target area. From November 23, 1992 through March 1993,
several heavy snowfalls and periodic blizzards produced record and
near-record snowfall accumulations. Similarly, large amounts of
snow also were produced over an extensive area in the Midwest
saturating the ground in spring, thereby contributing in part to
the flooding on the Mississippi River in 1993 as heavy spring and
early summer rain fell. Regionally, Western Kansas cattle growers
were adversely affected by the extraordinary snowfalls. However,
with the return of warmer temperatures and spring rains, we began
the 1993 crop season with generally excellent moisture at all soil
levels and a little too much in many areas. The general atmospheric
circulation for much of the 1993 season caused an unusually
persistent flow of easterly component lower-level winds in Western
Kansas, winds which brought in considerable amounts of moist air
having origins in the Gulf of Mexico---the most important element
needed to produce rainfall.

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Figures 7 and 8 are analyses of the WKWM rainfall observer
network administered by Western Kansas Groundwater Management
District #1. Figure 8 shows a rainfall pattern similar to 1992 in
that the bulk of the WKWM target area was above normal with only a
few small areas below normal. Greatest May - August rainfall, both
in amounts received and percentages, lay in northeast Lane County
where it was nearly double (100%) normal. Other areas greater than
70% above normal were found in central Wallace, cent~al to
northeast Wichita and southern Finney/northern Haskell counties.
The shaded areas in Fig. 8 show four small areas of slightly below
normal rainfall in 1993; three are on the periphery of the WKWM
target ~rea and one in southeast Kearny/southwest Finney counties.
In 1992 there were four such areas also slightly below. The other
low May - August rainfall areas were found in southeast Ford,
southwest Stanton and northwest Hamilton counties. However, all
such below normal rainfall areas were less than 10%.

Except during the wheat harvest period in early July, as we
progressed into summer, storm-day frequency became slightly higher
than "normal" and was accompanied by unusually greater numbers of
late night and early morning severe storms. Many of the storm
complexes which formed in Western Kansas or in Eastern Colorado,
moved through Western Kansas and continued eastward into even more
mois"C areas in the central and eastern parts of the Grain Belt
generating excessive rainfall in doing so. Rains began to taper
off around mid-August. Some storms occurring in the latter half of
September were associated with hail, high winds and heavy rainfall
caused winter wheat replanting in many areas.

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