Weather

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fxus63 kabr 070815 
afdabr 


Area forecast discussion 
National Weather Service Aberdeen South Dakota 
315 am CDT sun Sep 7 2008 


Short term...through Tuesday 


Region is expected to remain abnormally cool as upper trough 
persists across the High Plains/upper Midwest. Sref 850 mb anomalies 
continue in the -1 to -2 Standard deviation range along with the 
intermittent cloud cover from the active pattern combine to 
produce temperatures ranges 10 degrees below average through 
Tuesday morning. Temperatures return to slightly less abnormal for 
Tuesday in association with a low level jet that forms in response 
to approach of next system. 


As for precipitation chances...seeing much of shower activity head 
into western Minnesota with broad cloud free area upstream. Next shortwave 
to effect region in Montana at this time...so will keep majority 
of morning forecast dry. BUFKIT soundings suggest possibility of 
diurnally driven shower activity by late morning/early 
afternoon however...although opted out of thunder as middle level lapse 
rates remain unfavorable for much vertical development. 


Next wave to effect region passes south of County Warning Area...with probability of precipitation limited 
to south central counties. Again...BUFKIT soundings suggest 
possibility of shallow convective development during the late 
morning/early afternoon outside of cloud cover associated with shortwave. 




Long term...00z Wednesday through Saturday 
main challenge still in the extended is the expected frontal 
passage middle week and associated precipitation potential. 


Models still remain in overall agreement with the pattern. 00z 
Wednesday starts off with weak short wave ridging taking place over the 
County Warning Area...with next 500 mb system digging into the Pacific northwest. The models are 
now digging this sytem into the SW part of the Continental U.S....and cutting 
it off from the mean upper flow. At the surface...front still pushes 
through during the day Wednesday and Wednesday evening. With upper 
flow now perpindicular to surface flow...anticipate that the front 
will remain rather progressive in its passage...with drying taking 
place during the afternoon Thursday. Have removed mention of afternoon 
Thursday probability of precipitation due to this thinking. Have also continued to bloster 
dewpoints on Wednesday as southerly flow should draw more moisture 
northward. There is some concern for temperatures during the day 
Wednesday. The area remains under a fairly strong warm air advection regime...but 
increased cloud cover may inhibit temperature rise. The latest ensemble 
guidance is quite a bit cooler on Wednesday for all sites. Did 
undercut inherited Wednesday highs a few degrees...but still opted for a 
compromise between ensemble and operational guidance. 




&& 


Aviation... 
a slow moving cold front will continue to slowly slide southeast 
across the Dakotas. VFR ceilings will accompany the front as it 
moves...with Katy possibly seeing some MVFR ceilings through 15z. After 
15z VFR conds are expected for all terminal sites with few-sct100 
clouds. Visibilities will also be VFR through 06z Monday. 




&& 


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


$$ 
Short term...Connelly 
long term...Hintz 
aviation...Hintz 


Weather.Gov/Aberdeen