867 
fxus63 kmkx 060952 
afdmkx 


Area forecast discussion 
National Weather Service Milwaukee/Sullivan WI 
452 am CDT Sat Sep 6 2008 


Short term... 
shortwave trough exiting WI this am but a 100 knots jet stream over 
the northern and central rockies will progress eastward into the central USA 
and then shift northward into the Great Lakes. The westerly jet stream will 
remain progressive with shortwave troughs expected on a routine 
basis. 


The next shortwave over western NE will move across northern Illinois tonight 
with the GFS and European model (ecmwf) keeping the middle level frontogenesis and quantitative precipitation forecast 
to the south and east of southern WI. For sun a shortwave trough will 
move across central and northern WI with a weak cold front to progress 
across the state as well. GFS and European model (ecmwf) have most organized 
q-vector convergence and quantitative precipitation forecast over northern and central WI. Forecast soundings 
do indicate MLCAPES of only 200 j/kg but with eq levels near 500 mb 
so will continue mention of thunder. Northwesterly winds...weak cold air advection...and a 
drier airmass briefly prevails over the region later sun nt. 


An amplifying shortwave trough moves east across the Central 
Plains on Monday and to lower Michigan by 12z Tuesday. Weak cyclogenesis gets 
underway from MO to New York state during this period. The shortwave 
will act on a strong tropospheric thermal gradient to generate 
strong low to middle level frontogenesis from Illinois and in nwwd toward 
central WI. Widespread stratiform rain is expected but only 
increased probability of precipitation to likely due to some timing concerns. 




Long term... 
a large high pressure ridge will move across the western Great Lakes 
and central USA on Tuesday in wake of the synoptic low from Monday and 
Monday nt. The progressive flow will continue with decent warm 
advection developing for Wednesday and a well organized synoptic low and 
cold front for Thursday. 




&& 


Aviation...lingering middle level clouds associated with departing 
short wave trough will continue to thin from west to east across southern 
WI early this morning. Low level mixing and low level moisture will 
cause patchy stratus and light fog west of Madison as middle level clouds 
clear prior to sunrise. Few St may drift into kmsn area for an hour 
or two this morning. In addition...expect cumulus to redevelop for a time 
later this morning before dewpoints mix out a bit. Cumulus may briefly 
result in a period of MVFR ceilings. Inversion sets up rapidly this 
evening as winds decrease to 5kts or less. May be some light fog in 
the late evening but increasing high clouds expected to prevent 
widespread thicker fog. 




&& 


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


$$ 


Short/long term...20 
aviation/marine...11