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Area forecast discussion...updated 
National Weather Service Aberdeen South Dakota 
1034 am CDT Thursday Aug 21 2008 


Update... 
overall the forecast is in fine shape. Winds will likely approach 
advisory criteria...but for now will take a wait and see attitude. 
Temperatures look okay. 


&& 
Previous discussion... 
short term...today through Saturday 
the model and ensemble trend continues to agree now and is 
consistent through the short term. The big upper level spinner 
coming onshore this morning will track east and northeast across 
the far northern US and southern Canada through the short term. 
For today...strong south winds will again be the rule across the 
County Warning Area as the surface pressure gradient remains tight and low level 
mixing winds remain strong. Will hold off today with a Wind 
Advisory as the winds will be marginal. Otherwise...expect to see 
some mixing cumulus again today...especially east in the County Warning Area with some 
middle and high level clouds moving in from the west. Also...expect 
it to be a little warmer today across the County Warning Area with higher 850 mb 
temperatures. Still looking at a strong cold front moving across 
the County Warning Area after midnight through middle morning Friday. Plenty of 
MUCAPE in advance of this front with decent dewpoints and a good 
low level jet. With the middle level temperatures remaining warm and with high 
cinh values...it will be difficult for thunderstorms and rain showers to develop along the 
front as it moves through. Left slight chance probability of precipitation alone through 
this time period across the northern County Warning Area. Otherwise...cooler and 
much drier air will be moving into the County Warning Area Friday and Friday night 
as surface high pressure builds in from the northwest. Friday 
could be a breezy day across the County Warning Area as northwest winds mix out 
with the cold air advection. Winds will drop off Friday night with mostly clear 
skies and lower dewpoints. Temperatures will fall into the lower 
to middle 50s across the County Warning Area. Saturday will be sunny and dry with 
less wind and even cooler temperatures...especially northeast in 
the County Warning Area with surface high pressure across the area. 


Long term...Saturday through Monday 
latest guidance is in good agreement during this period with main 
feature of forecast being that first hint of fall with a slow 
return to summerlike conditions. Upper trough responsible for short 
term weather will be departing via the western lakes and upper 
ridging will end up dominating majority of the forecast. Surface 
high pressure will center overhead early...and slowly move east 
over the next several days. The result is a fairly cool start of 
the weekend...but with temperatures moderating towards the start 
of the work week aided by strong return flow around surface high 
ahead of next approaching western Continental U.S. Trough. 


&& 
Aviation... 
gusty southerly winds can be expected at all terminals today. 
Winds are expected to range from 20 to 30 miles per hour with gusts up to 40 
miles per hour. A cold front will move across the state Friday morning with 
winds shifting to the west then the northwest. Visby and ceilings are 
expected to remain VFR through this afternoon and evening. 
&& 


Abr watches/warnings/advisories... 
South Dakota...none. 
Minnesota...none. 
&& 


$$ 
Update...tdk 
short term...mohr 
long term...Connelly 
aviation...South Dakota 


Weather.Gov/Aberdeen