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Area forecast discussion for western South Dakota and northeastern Wyoming 
National Weather Service Rapid City South Dakota
216 PM MDT Tuesday Jul 7 2015

Short term...this evening through Wednesday night
issued at 200 PM MDT Tuesday Jul 7 2015

Latest surface analysis shows high pressure over the far eastern
Dakotas and Minnesota...resulting in breezy southerly return flow
over northeastern Wyoming and western South Dakota. Diurnal
heating and instability along a Theta-E ridge are combining with
lift associated with an approaching upper shortwave to produce
scattered showers and thunderstorms over northeastern Wyoming and
northwestern South Dakota early this afternoon. Shear remains
relatively weak at this time resulting in relatively short lived
convection cells. Cape and shear plots in the mesoscale-models
indicate that the most likely area for severe thunderstorms this
afternoon and early this evening would be over northwestern South
Dakota and possibly near the northern Black Hills...although
isolated severe thunderstorms cannot be ruled out over the rest of
the area too. The region of best instability will gradually move
southeastward tonight and on Wednesday with showers and
thunderstorms possible generally along and near the west-east oriented
boundary through the day on Wednesday. Shear profiles are
expected to remain relatively weak on Wednesday so widespread
severe thunderstorms are not expected. Temperatures on Wednesday
will continue to be cooler than average. A broad upper ridge will
begin to build over the northern plains on Wednesday night with
any showers or thunderstorm ending during the evening...with dry weather
through the rest of the night.

Long term...Thursday through Tuesday
issued at 200 PM MDT Tuesday Jul 7 2015

A shortwave will move through the southwest flow into
the region on Thursday...resulting in possible showers and
thunderstorms...mainly across northeastern Wyoming. Upper low across the
far western Continental U.S. Will slowly phase back into the main flow through the
end of the week...and upper ridge over the central Continental U.S. Will
strengthen...bringing above average temperatures and generarlly drier
weather to the area. Upper waves will cross Montana into ND and the low
will briefly restrengthen...bringing occasional sl chance probability of precipitation mainly
over northwest South Dakota Friday into Saturday. Otherwise most locations will
remain dry through the long term. Temperatures will generally reach
the upper 80s to lower 90s.


Aviation...for the 18z tafs through 18z Wednesday
issued at 200 PM MDT Tuesday Jul 7 2015

Some MVFR conds over the Black Hills with low clouds
this afternoon. Scattered -tsra will develop this afternoon across the County Warning Area and
continue into tonight. MVFR conds expected in heavier precipitation.
Otherwise VFR conds expected.


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


Short term...10
long term...pojorlie

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