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Area forecast discussion for western South Dakota and northeastern Wyoming 
National Weather Service Rapid City South Dakota
1125 am MDT Tuesday Jul 29 2014

Short through Wednesday night
issued at 221 am MDT Tuesday Jul 29 2014

The upper ridge will remain over the western Continental U.S. Today and
Wednesday. Isolated-scattered thunderstorms have developed overnight along
a northwest-southeast oriented Theta-E ridge located from northeastern Wyoming
into southwestern South Dakota as a weak impulse rounds the ridge.
The chance of thunderstorms will gradually shift southward later
this afternoon as synpotic scale subsidence spreads over the
region. Highs today will be slightly cooler than average and have
lowered parts of northeastern Wyoming below guidance due to the
expectation of increased cloud cover over that region into the
early afternoon. Dry weather is expected tonight and on Wednesday as
subsidence associated with the upper ridge affects the region.


Long term...Thursday through Monday
issued at 221 am MDT Tuesday Jul 29 2014

The ridge over the western United States is forecast to remain in
place through the extended period...but some weakening is expected
over the weekend. Cool northwesterly upper level flow will continue
to produce slightly below average temperatures for the northern High
Plains. Temperatures will continue to be near or slightly below
seasonal averages. Through the end of the week abundant sunshine and
southeasterly flow may lead to a slight chance of thunderstorms
across the higher terrain of the Black Hills. Weak flow and limited
moisture will likely keep the activity to isolated showers/storms.
However by Saturday the ridge yields to an onslaught of short wave
energy and weak systems are allowed into the northern High Plains
through early next week. Hence the chance for thunderstorms has
been increased for Saturday through Monday.


Aviation...(for the 18z tafs through 18z wednesday)
issued at 1124 am MDT Tuesday Jul 29 2014

Scattered -shra and isolated -tsra will continue over northeast Wyoming
and southwest South Dakota through this afternoon. Local MVFR conditions
possible in precipitation. Elsewhere VFR conditions are expected
through the forecast period.


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


Short term...10
long term...CArpenter

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