Weather

492 
fxus63 kgrb 280913 
afdgrb 


Area forecast discussion 
National Weather Service Green Bay WI 
413 am CDT Thursday Aug 28 2008 


Short term...today through Friday. Showers and thunderstorms 
moving through the region early today as strong low level jet 
brings up moisture ahead of weak front. Think that severe weather 
threat will be hampered by residual clouds and rain today...but if 
we get sunshine later in the day there could be a few storms with 
gusty winds. Drier air arrives tonight with warm...dry weather 
expected Friday. 


Long term...Friday night through next Wednesday. Main forecast focus through the 
upcoming Holiday weekend will be temperatures as quiet weather pattern to 
prevail over the region thanks to hi pressure. Forecast becomes more 
challenging toward the middle of next week as an upper trough and 
associated cold front approach WI. 


A broad area of hi pressure to extend from the Midwest into the Great 
Lakes region Friday night and should provide for mostly clear to partly cloudy 
skies with a relatively light west-SW wind. Not much change in airmass 
aloft...thus would expect min temperatures to be close to values 
witnessed Thursday night. A few of the models want to drop a weak surface trough 
southward into WI on Sat...but with such a dry airmass in place...don't 
see much more than a few clouds from this feature (assuming it even 
exists). Otherwise...hi pressure remains over the Great Lakes through 00z 
Sunday. A touch of warm air advection will allow temperatures to rise back into the upper 
70s to lower 80s for Sat. 


A new upper trough digs into the Pacific northwest Sat night which allows for 
downstream upper ridging to take place over the Midwest/western Great 
Lakes. May need to nudge min temperatures up a couple of degrees over southern 
sections of the forecast area as temperatures aloft continue to slowly warm. 
While the upper trough moves inland toward The Rockies on Sunday...the 
upper ridge remains parked over the Great Lakes. Winds are expected to 
become more from a S-southeast direction...thus inland locations will see 
warmer temperatures with readings in the lower to middle 80s. This would put 
temperatures about 10 degrees above normal for the last day of August. 


Tranquil weather to persist over NE WI to start the work week with 
the upper trough over The Rockies and the upper ridge over the eastern Continental U.S.. 
mean flow aloft will be from the SW for WI on Monday which is expected 
to not only bring warm temperatures...but a gradual increase in low level 
moisture. 800 mb temperatures residing in the upper teens should send surface temperatures 
into the middle 80s (except right along the lake and bay). 


Models Apr to be trying to get into better sync with the handling of 
the upper trough toward the middle of next week. The wild card could be 
where tropical system 'gustav' will be located and whether it will 
have any impact on the speed with which systems traverse the Continental U.S.. 
it aprs that the eastern Continental U.S. Upper ridge will be more of a factor on the 
approaching upper trough (by slowing it down). If this trend continues... 
later shifts may be able to go completely dry over NE WI on Tuesday and 
focus more on the Tuesday night or Wednesday time frame for our next chance of 
showers and thunderstorms. 
&& 


Aviation...thunderstorms with MVFR ceilings and visibilities expected 
through early afternoon. Then VFR/MVFR weather expected later in the day 
with scattered thunderstorms. Haze will likely be common this 
afternoon with visibilities around 5 miles. Will become VFR overnight and 
Friday. 
&& 


Grb watches/warnings/advisories... 
none. 
&& 


$$ 
Rdm/kallas