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Area forecast discussion for western South Dakota and northeastern Wyoming 
National Weather Service Rapid City South Dakota
328 am MDT Monday Aug 31 2015

Short through Tuesday night
issued at 327 am MDT Monday Aug 31 2015

Water vapor imagery shows strong upper wave crossing central to eastern Montana
into northern Wyoming. Surface analysis shows low pressure across the western/central
Dakotas ahead of the upper wave...with a cold front quickly pushing
through eastern Montana/central Wyoming toward the County Warning Area. Temperatures across the County Warning Area are in the
60s/70s...even 80s across the downsloping north/NE Black Hills. Behind the
front...observation showing temperatures dropping into the 50s with winds of 15 to
30 gusting to 30 to 40 miles per hour. Radar shows shower activity crossing western
South Dakota...however nearly all the precipitation is virga with little to no rain
reaching the ground. The cold front will push through NE Wyoming to western
South Dakota in the next 4/5 hours or so...and clear scntrl South Dakota by middle to late
morning. Hrrr suggests winds will generally be 15 to 25 miles per hour with
gusts to 30 to 40 miles per hour...but is also showing stronger winds across
the western South Dakota plains north and east of the Black Hills. Wind Advisory
criteria winds are expected...however just for couple hours or so
immediately after the frontal passage. Could see lingering rain showers activity early
this morning as models are having a hard time deciding how much
precipitation will reach the ground. Will lean toward a dry forecast for
now considering the latest radar imagery...but will reassess closer
to 12z. Otherwise a dry day is expected with much cooler
temperatures and clearing skies. Highs will reach the upper 70s to
upper 80s. Temperatures tonight will drop into the 50s to lower 60s. Return
flow will set up by Monday nght/Tuesday morning with warmer temperatures expected.
Highs will return to the middle 80s to middle 90s. Dry weather will
continue Tuesday/Tuesday nght with broad southwesterly flow aloft persisting.

Long term...Wednesday through Sunday
issued at 327 am MDT Monday Aug 31 2015

The upper trough will remain over the North American Pacific
coast through most of the week...eventually moving inland by the
weekend as another impulse drops into the upper trough from the
northwest. This pattern will lead to continued very warm
temperatures over the northern plains both Wednesday and Thursday.
Friday and Saturday will be slightly cooler...with much cooler
temperatures on Sunday and Monday behind a relatively strong cold front
which will pass through the area early Sunday. Dry weather is
expected on Wednesday and Thursday with a chance of thunderstorms
each day from Friday through the weekend as a series of upper
impulses cross the region and cooler air flows in at the surface.


Aviation...for the 12z tafs through 12z Tuesday morning
issued at 327 am MDT Monday Aug 31 2015

Breezy northwest winds will follow a cold front this morning. VFR
conditions are expected today and tonight.


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


Short term...13
long term...10

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