933 
fxus63 kgrb 282026 
afdgrb 


Area forecast discussion 
National Weather Service Green Bay WI 
326 PM CDT Thursday Aug 28 2008 


Short term...tonight and Friday. Cold front now extends from near 
imt to Wautoma...with clouds clearing behind. Low clouds with and 
ahead of front has not allowed for sig destabilization of 
atmosphere...though strong shear with 100+ jet pushing into Lake 
Superior enough to get some activity going this afternoon over 
eastern WI. More diurnal type activity over northern Minnesota associated 
with cold pocket will stay west/north of area. High pressure 
building in tonight will lead to light winds...some patchy fog 
west where rainfall was heavier early this morning. Upstream temperatures 
not as warm as guidance...though with westerly flow and 
sun...will go slightly below for highs Friday. 


Long term...Friday night through next Thursday...main forecast concerns 
are temperatures throughout the period...and precipitation chances associated with 
a slow moving cold front and possible interaction with tropical moisture 
from Gustav during the middle-late part of next week. 


Forecast starts off pretty straight-forward as high pressure at the surface 
and aloft shifts slowly east through the Great Lakes and intensifies. 
This will result in another prolonged dry period...with developing 
return flow leading to much above normal maximum temperatures. Have boosted 
maximum temperatures well into the 80s for the weekend and early next week. 
With a more amplified flow pattern developing...models have 
slowed the progression of the approaching cold front for the middle 
part of the next work week. With this in mind...have opted to remove 
precipitation from the Tuesday forecast. 


Forecast gets tough for the Tuesday night-Thursday period...as models disagree on 
how quickly the front will move through the wstrn Great Lakes region. 
The GFS (with support from most of it's ensemble members) quickly 
pushes the front through WI Tuesday night...and moves it into the Ohio 
Valley Wednesday night into Thursday. On the other end of the spectrum...the 
European model (ecmwf) moves the front through WI on Wednesday...and stalls it just to 
our east Wednesday night into Thursday. This sets the stage for a potential 
overrunning event as tropical moisture from Gustav surges north. 
Since the European model (ecmwf) is usually quicker to pick up on significant 
trends in the medium range...have opted to lean the forecast in its 
direction. Have added probability of precipitation for Wednesday night into Thursday... with the 
highest probability of precipitation in our southeast counties...closer to the front. Confidence 
is low for this part of the forecast. 
&& 


Aviation...cold front moving through state with clearing 
expected west to east this evening...with VFR ceilings expected all 
sites after 01z. Scattered shower/thunderstorm activity expected grb and 
eastern airports through 00z. Clearing skies and light winds will 
lead to patchy fog central and north central taf sites given 
lingering moisture from last nights rains. 
&& 


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


$$ 
Te/kieckbusch