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Area forecast discussion for western South Dakota and northeastern Wyoming 
National Weather Service Rapid City South Dakota
1128 PM MDT Monday Sep 1 2014

Short term...this evening through Tuesday night
issued at 118 PM MDT Monday Sep 1 2014

Water vapor shows short wave moving from eastern Wyoming into western South Dakota...with
upper ridge over the Pacific northwest building into the northern rockies. At the
surface...weak cold front associated with short wave has moved through all but
scntrl South Dakota with high pressure building into eastern Montana/eastern Wyoming. Scattered
rain showers/thunderstorms and rain continue to develop over the County warning forecast area due to short wave.

Tonight...short wave will push quickly east of the County warning forecast area this
evening bringing rain showers/thunderstorms and rain to an end...and clearing skies later
tonight. A brief period of breezy northwest winds will subside by late
evening.

Tuesday...upper ridge building eastward into the northern plains will bring
mostly sunny skies and warmer temperatures.

&&

Long term...Wednesday through Monday
issued at 118 PM MDT Monday Sep 1 2014

An upper trough will cross the northern parts of the Continental U.S.
From the Pacific northwest into the northern plains Wed/Thu. Models show decent
agreement that the best forcing and bulk of precipitation will remain north
of the County Warning Area...though far northwestern South Dakota could see some precipitation clip the area
Wednesday night. In addition...surface low will cross the Dakotas Wednesday/Thursday
with a strong cold front crossing the region Wednesday night...bringing a
period of gusty northwest winds above average temperatures Wednesday will give
way to below average temperatures Thursday. Beyond Thursday there are some diffs in
models as a split-flow pattern sets up for the end of the week.
However...in the mean there will be a trough over the west with a
ridge over the scntrl-southeastern Continental U.S.. this will bring periodic short-
wave troughs across the County Warning Area...albeit with limited forcing and
moisture. For now will keep slight chance probability of precipitation for the periods with the
most consistent timing of waves. Near average temperatures are expected for
the end of the week.

&&

Aviation...(for the 06z tafs through 06z Tuesday night)
issued at 1126 PM MDT Monday Sep 1 2014

Shortwave ridging ahead of the next Pacific northwest upper trough will
support VFR conditions through the period.

&&

Unr watches/warnings/advisories...
South Dakota...none.
Wyoming...none.
&&

$$

Short term...Johnson
long term...bunkers
aviation...jc

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