271 
fxus63 kpah 091001 cca 
afdpah 


Area forecast discussion...corrected 
National Weather Service Paducah Kentucky 
350 am CST Friday Jan 9 2009 


Discussion... 
primary forecast concern remains potential for precipitation tonight 
and Saturday...followed by much colder air next week. 


Ridge of surface high pressure was oriented parallel to and in the 
vicinity of the Appalachian Mountains early this morning. This high 
will shift east today...allowing for an increase in southerly winds 
as low pressure organizes over the Southern Plains. This will result 
in warmer temperatures for the immediate area...as highs reach the 
upper 40s to lower 50s. Sunshine will abound for the first half of 
the day...but low clouds will likely begin to overspread the western 
half of the region during the afternoon. Forcing for precipitation 
appears to be best concentrated after 00z...so we eliminated any 
mention thereof this afternoon. 


The low pressure system shifts northeast across the region tonight. 
As the wave approaches...showers will break out across most of the 
region this evening...then continue overnight. A moist southerly 
fetch at 850 mb along with decent elevated instability should 
support a round of scattered thunderstorms as well...especially over 
the southern 2/3 of the area. The best time frame for thunderstorm 
activity appears to be from 03-09z. 


Falling temperatures will be the story on Saturday behind the cold 
front. We maintained precipitation chances through the course of the 
day. While most of the lingering precipitation will be in liquid form early 
in the day...light snow is more probable as the thermodynamic 
profile cools during the course of the day. Any wintry precipitation 
should be light enough so as to not result in any accumulation. 


High pressure will build in for Sunday...resulting in dry and milder 
conditions. After that...into the cold Arctic ice box we go as a 
series of frontal systems usher colder air into the region as the 
week progresses. Still some uncertainty as to how low we will 
go...but it is certainly possible that portions of the area may 
struggle to reach the 20s for highs...with lows in the single digits 
later in the week. Our new forecast package resembles the previous 
forecast with very few changes necessary beyond Sunday. 


Temperatures today are reflective of a MOS blend. However...we threw 
out MOS tonight and Saturday in favor of a nam12/gfs40/sref blend. 
This better accounts for rising temperatures and dew points ahead of 
the low tonight...followed by falling temperatures behind the front 
on Saturday. 


&& 


Aviation... 
VFR conditions expected through taf period. Southeast to south 
winds at 6 kts or less will continue overnight...then increase to 10 
to 15 kts with gusts near 20 kts possible by late morning. Winds 
will decrease to around 10 kts or less after 23z...with ceilings of 
broken-ovc100 spreading across the region during the evening hours. 


&& 


Pah watches/warnings/advisories... 
Kentucky...none. 
MO...none. 
Illinois...none. 
In...none. 
&& 


$$ 


Rjp/drs