957 
fxus63 kfsd 201542 
afdfsd 


Area forecast discussion for southeast South Dakota/southwest Minnesota/northwest Iowa 
National Weather Service Sioux Falls South Dakota 
1030 am CDT Sat Mar 20 2010 


Discussion... 


Solid stratocu deck continues to erode over the central portions of 
the County Warning Area this morning...though as expected with decent low level 
lapse rates beginning to see scattered redevelopment of clouds 
across a good bit of the western and central parts of the area. In 
light of that...think partly cloudy is the way to go for the 
remainder of the afternoon. Temperatures still on track for highs in 
the middle and upper 30s. Minor updates out. /Jm 


&& 


Aviation... 


Low clouds continuing to erode over the area this morning...but do 
expect some redevelopment into the afternoon...with scattered 
coverage of 3 to 4 kft ceilings across the area. Clouds will clear out 
by this evening with VFR conditions through tonight. 


&& 


Previous discussion... 


North-northwesterly flow of fairly cold air today...and with a decent lapse rate up 
to 850 mb...SC deck may hang around especially central to southern County Warning Area and will go 
partly cloudy. Clear skies and light winds tonight under surface ridge should permit 
temperatures to drop on cold side of guidance. The ridge from to surface to aloft 
will move slowly southeastward over County Warning Area sun through Monday morning flwd by a south-southwesterly 
flow of gradually warmer air. Uppd the temperatures for the western to northern County Warning Area 
with this pattern through Monday as warmer air aloft should translate to 
the surface with stronger middle March sun and no leftover snow cover. Southeastern 
County Warning Area should still be a lit more under the influence of Cool Ridge and 
closer to melting recent new snow in Nebraska and Iowa...and may also 
have to watch out for patchy fog in the late night or early morning. 
Monday night should be a relatively mild night with mixing ahead of cold front 
that looks to move east-southeastward over County Warning Area faster than previous forecast for 
Tuesday...so cut back highs in the northwestern half of the County Warning Area. Played with 
slight chances of light precipitation for Tuesday through Wednesday...with middle level boundary 
sagging slowly southeastward through County Warning Area. Put slight chance northestern County Warning Area Tuesday...southern County Warning Area 
Tuesday night...and kept it for southeastern County Warning Area for Wednesday...based on composite of 
models. Does not look to be much moisture or dynamics though. /Rsr 


&& 




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


&& 


$$