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Area forecast discussion for western South Dakota and northeastern Wyoming 
National Weather Service Rapid City South Dakota
502 PM MDT sun Sep 14 2014

Short term...this evening through Monday night
issued at 142 PM MDT sun Sep 14 2014

Central Canadian upper level trough will shift east
in the period...with the western noam ridge building into the
northern plains. One last associated southern periphery upper level
trough will push through the northern plains this evening...possibly
supporting a rain showers across the far southeast. Otherwise...clouds will clear
in the period...with much warmer weather on tap for Monday. deck from weak positive Theta-E advection under a remnant
subsidence inversion...will clear west to east this evening as the
upper trough shift east. Weak surface trough advecting through the
region may support a shower around Tripp County this evening. Not
too excited about rain chances given dismal moisture profiles and
general weak forcing. Opted for slight chance probability of precipitation. Clearing with
light winds and weak surface high over the area will support another
cool night with frost possible once again western half.

Monday...surface high will shift southeast of the area with Lee side
troughing supporting increasing southerly return flow. Warmer
conditions can be expected with highs in the 60s and 70s...warmest
over NE Wyoming. Warmer night on track Monday. Ongoing ll pressure falls
will support a weak nocturnal low level jet with terrain induced downsloping
expected in usual areas at times in addition to NE Wyoming. This should
hold temperatures up at many locations.


Long term...Tuesday through Sunday
issued at 142 PM MDT sun Sep 14 2014

An upper level ridge of high pressure will build across
the western Continental U.S. Through middle week...bringing dry conditions and
near to above average temperatures. Upper ridge slides across the
County Warning Area on Thursday /with thermal ridge over the area/ will see the
warmest temperatures of the week on Thursday. A chance for showers will
be possible by the late afternoon/evening hours on Thursday over
the higher terrain in northeastern Wyoming and the Black
Hills...given western ridge position. Upper ridge continues to
slide east and break down as an upper trough swings through the
northern plains on Friday and Saturday. With increasing Pacific
moisture...there will be a chance for showers and thunderstorms
and slightly cooler temperatures. Western ridge then reforms and
builds again on Sunday...resulting in dry conditions for the
forecast area.


Aviation...(for the 00z tafs through 00z Monday evening)
issued at 501 PM MDT sun Sep 14 2014

VFR conditions and lght and variable winds are expected through
the forecast period.


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


Short term...jc

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