Weather

848 
fxus63 kunr 280224 
afdunr 


Area forecast discussion for western South Dakota and northeastern Wyoming 
National Weather Service Rapid City South Dakota 
824 PM MDT Wednesday Aug 27 2008 


Discussion...lates surface analysis shows surface trough over the 
western Dakotas. Upper level analysis shows near zonal flow across 
the northern Continental U.S....with strong jet moving across the Pacific northwest. 
Good deal of middle and high cloudiness associated with the jet 
energy is passing over the region...especially northern portions. 
Regional radars showing some weak returns...mainly in the middle 
levels of the atmosphere...with little if any moisture reaching 
the ground. 


Relatively quiet weather expected for the next several days...with a 
warming trend toward the weekend. Only minor changes made to the 
short term forecast. 


For tonight...skies will remain partly to mostly cloudy as 
trough/front continues to moves south and east. Plenty of middle and 
upper level moisture and upper level energy will cross the 
northern plains...the bulk of it passing north of the area. 
However...low levels will remain quite dry. Will leave a slight 
chance for light showers across portions of NE Wyoming and northwestern South Dakota through 
the evening...with a slight chance for showers across far south 
central South Dakota later tonight as trough interacts with better low level 
moisture...increasing middle level Theta-E advection...and some 
instability aloft. Lows will mostly be in the 50s...40s in the 
usual cooler spots. 


A tight pressure gradient will develop over western South Dakota behind the 
surface trough on Thursday...which will lead to breezy to windy 
conditions across most of the plains. Temperatures will remain on the 
cooler side...with highs again mostly in the 70s. Warmer air will 
begin to return of Friday as southerly flow develops. Highs will be 
back into the 80s across the plains...70s in the hills. 


Extended...Flat Ridge will shift east of the region on Saturday as a 
trough digs into the Pacific northwest. The trough will move into 
the central rockies on Sunday night as a cold front slowly moves 
across the area. This system will bring a chance of showers and 
thunderstorms to the area through Tuesday morning. An active weather 
pattern will remain over the region through the middle of next 
week. 






&& 


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


$$