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fxus63 kmkx 212041 
afdmkx 


Area forecast discussion 
National Weather Service Milwaukee/Sullivan WI 
241 PM CST Sat Nov 21 2009 


Rather stable weather pattern over US for the next few days. Upper 
level ridging holds over the eastern half of the country while 
trofing occurs over the middle of the U.S. The ridge should protect 
the southeast third of the state...including our County Warning Area...from any 
intrusion of precipitation through Monday. Satellite does show 
moisture/clouds streaming north through the Mississippi 
Valley...on the west side of the ridge. Little expansion to the 
east is anticipated. Increasing middle level southwest flow will 
stretch from the Oklahoma Panhandle to northwest Wisconsin by 
Sunday afternoon as the first round of energy digs a trough into the 
Central Plains. 


As this first short wave arrives and pushes into the ridge... 
more clouds will spread into the western County Warning Area...but the chance for 
precipitation should stay west of our area. Overall through 
Monday...the west will be mostly cloudy while the east stays 
partly cloudy. Temperatures will remain unseasonably mild. 


A second...much stronger...Pacific northwest short wave digs into 
the Central Plains Monday night. Wow...can the Pacific northwest 
catch a break...they have been getting pounded. This short wave 
closes off quickly and heads for northern Illinois Tuesday and 
Tuesday night. The first main band of rain associated with this 
strong low will lift north into southern Wisconsin Tuesday 
afternoon. The model guidance is now in fairly good agreement on 
the timing. This hasn/T been the case over the last week or so. 
Temperatures will be warm enough initially for this to be an all rain 
event. The low quickly occludes and sucks in and wraps around dry 
air which makes precipitation chances from Tuesday night into Wednesday 
rather murky. Would expect scattered light stuff during that time. 


Then a third short wave dives into the back side of the departing 
low on Wednesday...looking more like an Alberta clipper...though 
admittedly it is a little too far south for that. But...it 
originates farther north and pulls down a surge of colder air into 
the back of the exiting Great Lakes low. The GFS brings an area of 
associated quantitative precipitation forecast across the southern County Warning Area Wednesday afternoon and Wednesday 
night...that would be all snow and resulting in a few inches of 
accumulation. The European model (ecmwf) has a much more northern placement of the 
quantitative precipitation forecast over central Wisconsin...keeping US in the much lighter 
quantitative precipitation forecast/snowfall regime. How this third short wave energy interacts 
and evolves within the lead Great Lakes low is very complicated 
and prone to significant run to run deviations over the next few 
days. Stay tuned. 


&& 


Aviation...limited aviation concerns over the next 24 hours. Winds 
will likely stay up a bit tonight...limiting the chance for fog. 
Could see some MVFR visbys if winds are light enough...mainly after 
midnight. Otherwise...VFR conditions will prevail. 


&& 


Mkx watches/warnings/advisories... 
WI...none. 
Lm...none. 
&& 


$$ 


Short/long term...Davis 
aviation/marine...Vancleve