042 
fxus63 kpah 030837 
afdpah 


Area forecast discussion 
National Weather Service Paducah Kentucky 
237 am CST Wednesday Dec 3 2008 


Discussion... 


Two weather systems to deal with in the next seven days. The first 
one will begin to affect the region today and the second one the 
first half of next week. 


The NAM and GFS continue to be in decent agreement on timing and 
placement of the approaching system. The cold front associated 
with this system currently currently extends southwest from the 
western Great Lakes into the Central Plains...and is forecast to 
race from west to east across the region this afternoon and 
evening. Latest timing would have it entering the western sections 
of our forecast area around 3/21z and clear the southeast corner of our forecast area by 
4/06z. 


Low level moisture/clouds will increase rapidly today ahead of the frontal passage on 
strong south to southwest low level flow. Consequently a high 
likelihood of rain/showers is expected with this system. Models 
continue to show cold air entrainment into the backside of the 
system possibly changing the precipitation briefly from rain to a mix of 
light sleet or snow before ending. The window of opportunity is 
fairly narrow...so do not expect accumulation. The precipitation 
should be moving out of the eastern sections of the forecast area by 12z 
Thursday. 


Regarding the Saturday clipper system that was forecast to remain 
just north and east of our forecast area...the 3/00z GFS and the 2/12z European model (ecmwf) 
had brought the .01 quantitative precipitation forecast line farther south and west into the 
northeast sections of our County Warning Area. Since the day shift had removed all 
probability of precipitation across our forecast area on Saturday based on previous model runs...decided 
to not flip flop and keep it dry. Looks like this may have been a 
good decision because the 3/00z European model (ecmwf) hot off the press has moved 
the chances for precipitation back to the north and east of our forecast area. 


Next system begins to affect the region starting late Monday and 
continuing through middle week. Potential for precipitation with this system 
looks good at this time...however latest GFS and European model (ecmwf) quite 
different on timing and placement. Will not make any changes 
beyond Saturday at this time. 


&& 


Aviation... 
stratus noticed on satellite imagery over eastern Texas will 
accelerate/develop toward the area today...and overspread the area 
from 12z to 18z. It will gradually lower through the MVFR range 
with time during the afternoon...and may eventually dip to IFR 
levels near and behind the cold front Wednesday evening. 


Rain will also develop ahead of the front as ceilings lower...but at 
this time...it appears that visibilities should stay at VFR levels 
ahead of the front. Some drizzle/light rain or fog could reduce them 
to MVFR levels behind the front. 


00z models are in decent agreement in strong/gusty south southwest 
winds continuing through the day ahead of the front...before 
abruptly shifting to the north northwest behind it. Gusts ahead of 
and behind the front will top 20kts in most locations. There is 
still some variability in the 00z models on exact frontal 
timing...so confidence in timing the wind shift is not particularly 
high. 


&& 


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


$$ 


Public.....Jap 
aviation...drs