622 
fxus63 kfsd 201526 
afdfsd 


Area forecast discussion for southeast South Dakota/southwest Minnesota/northwest Iowa 
National Weather Service Sioux Falls South Dakota 
1025 am CDT Wednesday Aug 20 2008 




Discussion.... 
minimal cloud cover this afternoon with some cumulus development...but 
once again cumulus will disappear this evening with the lost of daytime 
heating. Srly winds will increase to 20 to 30 miles per hour this afternoon and 
temperatures will rise into the middle to upper 80s. Forecast right on 
track for today...so only minor tweaks to the grids. 




&& 


Aviation... 
strong srly winds this afternoon and again tomorrow. VFR today and 
most of tonight...but MVFR possible late tonight near sux as low 
level moisture stream nwrd and stratus deck around 3000 feet form. 


&& 




Previous discussion... 
a few cloud patchs 5-10k feet developing and moving northward over area early this morning 
but no indicatn of a gnrl moisture increases that level till latr tonight when 
northward driftg shortwave approaches. So...sill looks like mosunny today. Gradnt 
continues to increases and a breezy to windy day expectd. With a pretty 
straight gradnt and fallng pressure think winds even far west/northwest will stay 
below advisory levels despite decent mixg down of strong low level wind field. 


Above mention shortwave will appchg southeastern/eastern forecast area late tonight and brush 
over it Thursday. Pretty decent middle cloud shield expctd and some low clouds as 
well...so a mostly cloudy day expectd over northwestern Iowa and possibly nearby areas. 
After hi temperatures today close to Tuesday...coolng in store for southeastern forecast area 
for Thursday. Will keep slight chance/chance shower mention southeastern forecast area for Thursday. 
Despite wimpy lift and support...moisture seems ample to keep as it 
wont take much to produce a few so so showers. 


NAM has come in line with other models this morning on decent movmnt of 
cold front across forecast area Friday. This wont leave much room for thunderstorm threat 
over most of forecast area. Threat should be confined to central and eastern 
forecast area and pass pretty quickly central and NE...but may linger well 
into the night far southeastern forecast area in northwestern Iowa east of sux. Friday temperatures will 
see some evening out with some coolng behind fnt west but warmr temperatures 
than Thursday east after Thursday cool pocket gets chased out. 


No change in dry Sat through Tuesday forecast...mild over weekend with a little 
warmng Monday. No excitement as of yet about cold front GFS brings into area 
Tuesday...or about diffrnt looking upper low European model (ecmwf) has at southwestern corner of 
County Warning Area. In either event pattrn not favorable for bringing widespread moisture up 
into northern plains despite these features. 


&& 


Fsd watches/warnings/advisories... 
South Dakota...none. 
Minnesota...none. 
Iowa...none. 
NE...none. 


&& 


$$ 
Update...liebl 
Williams