439 
fxus63 kmpx 300814 
afdmpx 


Area forecast discussion 
National Weather Service Twin Cities/Chanhassen Minnesota 
314 am CDT Sat Aug 30 2008 


Discussion... 
the main regional weather highlights over the weekend will be 
increasing winds and warmth. Surface high pressure will continue shifting 
south/east of the area today...as surface cyclogenesis ensues over 
eastern Montana and the extreme western Dakotas. The result 
locally will be increasing surface winds this afternoon...with 
breezy conditions developing over west central Minnesota. Continued 
surface low intensification and the attendant tightening pressure 
gradient /pressure falls/ over the County Warning Area will yield even stronger winds 
on Sunday and Monday. NAM/GFS BUFKIT profiles indicate surface 
winds in the middle/upper 20s /knots/ across most of the Minnesota portion 
of the forecast area...with gusts to around 35 knots. 850mb 
temperatures climb into the low 20s /celsius/ across much of west 
central and central Minnesota today and Sunday...which should contribute 
to highs in the 85 to 90 degree range across the Minnesota portion of the 
forecast area as deep mixing occurs. Slightly cooler /although 
still warmer than normal/ highs in the 80s will occur across west 
central WI. 


Minimum relative humidity values this afternoon will range between 25 and 35 
percent...which raises fire weather concerns...especially as winds 
increase this afternoon. Increasing moisture advection/dewpoints 
on Sunday and Monday should slightly diminish the fire weather 
threat. 


Frontal passage timing still appears to occur in the Tuesday to Wednesday 
timeframe...during which high chance probability of precipitation have been maintained. 
Forecast confidence decreases on Wednesday and beyond in the wake 
of the front...as the European model (ecmwf) and GFS differ dramatically on the 
evolution of Hurricane Gustav. For now...have not made any notable 
changes past Tuesday night. 




&& 


Aviation.../06z taf issuance/ 


Weakening surface trough from northwest WI to near kmsp will slide through eau lt 
tnght..but winds very light. T/dew point spreads dcrsg enough that local fog may 
form lt...main threat probably at eau whre bit higher dewpoints vicinity fnt. 
Incrsg pressure gradient mainly west sites lt morning. Will probably afternoon gusts 20 kts 
or bit stronger axn and rwf. 




&& 


Mpx watches/warnings/advisories... 
Minnesota...none. 
WI...none. 
&& 


$$ 


Ls/bap