767 
fxus63 kunr 200733 
afdunr 


Area forecast discussion for western South Dakota and northeastern Wyoming 
National Weather Service Rapid City South Dakota 
130 am MDT Sat Mar 20 2010 


Discussion...water vapor shows upper trough axis moving through the northern 
plains with upper ridge building into the northern rockies. Surface analysis 
places surface ridge across the Black Hills region. Lingering snow flurries are 
quickly pushing south of our area. 


Sat and sun...warming trend in store as upper ridge builds eastward into 
the northern plains. High temperatures in the 30s/40s today will give way to 
50s/60s on sun. Plenty of sunshine both days. 


Monday...upper ridge begins to break down as upper trough moves through the northern 
rockies. Associated cold front will push through during the day although most 
areas will still reach the 50s/60s before the cooler air filters in. 
There should be enough instability for some Post frontal -shra Monday 
afternoon...possibly mixing with snow Monday night. 


Extended...the upper wave/trough will slide east of the area Tuesday 
with some lingering showers possible on the backside. Temperatures 
will be noticeably cooler with highs in the upper 30s to around 50. 
Weak upper ridging will build in from the west for the middle of the 
week with dry weather and temperatures warming back up to near or 
above seasonal averages. 


&& 


Aviation...VFR conditions expected through the forecast period. 


&& 


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


$$ 
Johnson/calderon