688 
fxus63 kjkl 061909 
afdjkl 


Area forecast discussion 
National Weather Service Jackson Kentucky 
309 PM EDT Monday Oct 6 2008 


Short term.../tonight through Wednesday night/...updated 


The main weather feature in the short term period will be the 
approaching cold front and upper level low Tuesday night through 
Wednesday night. First...for tonight and Tuesday...we should see dry 
weather continue. Skies will be mainly clear tonight with just some 
cirrus moving across the area after the diurnal cumulus dissipates. Could be a 
little patchy smoke again near Red River gorge tonight. Diurnal cumulus 
and some cirrus can be expected again for Tuesday. Should be warm again 
on Tuesday with highs again from 80 to 85. Moisture begins to 
increase ahead of the front Tuesday night. Prefer to lean toward the 
WRF solution in the short term. Will bring in high chance probability of precipitation in 
the west...tapering to slight chance in the east. Southeast 
downsloping flow should delay the eastward advancement of the precipitation. 
The best chance for showers should be Wednesday into Wednesday 
evening. Not a lot of instability...but there is enough shear where a 
few thunderstorms could develop as well Wednesday afternoon. Will go 
with likely probability of precipitation for most of the area...except in the extreme east 
where downsloping could again limit precipitation development. Cross 
sections show it may take until afternoon for the column to saturate 
over a good portion of the area. A digging 500 mb trough will be moving 
through the Mississippi Valley...where a cutoff 500 mb low is expected to 
develop. Am concerned this could also rob some of the moisture this 
far north...so did not go with categorical probability of precipitation. In fact...kept probability of precipitation 
at 50 over far southeast Kentucky due to the downsloping. Precipitation 
across the area should begin to wind down later Wednesday night as 
moisture moves east of the area. As for quantitative precipitation forecast...used scaled down HPC 
numbers. Should see up to a tenth of an inch in the far southeastern 
areas if showers are able to make it there...with up to a half inch 
along our western tier of counties in the County Warning Area. 


Long term.../Thursday through Monday/...updated 


The models are in better agreement early in the period...then 
diverge by the weekend and early next week. Went closer to a blend 
of the European model (ecmwf) solution and the latest HPC guidance. An 500 mb low...with 
a weak surface reflection...is expected to be over the southeastern 
Continental U.S. Thursday. Will keep slight chance to chance probability of precipitation across the 
area...with lingering moisture over the area. The GFS develops a 
stronger low...with the Canadian and European model (ecmwf) slightly weaker. Prefer a 
solution slightly stronger than the European model (ecmwf)...but not as strong as the 
GFS. The upper low will drift east Friday...but most of the 
moisture should be east of our County Warning Area...so will keep just slight chance 
probability of precipitation in. Things should dry out Friday night as the moisture pulls 
further east of the area. Significant differences in the handling of 
the low show up in the models by Friday night and Saturday. 
Following the idea of an European model (ecmwf) and HPC blend...this allows the 500 mb 
low to drift drift east-southeast off the southeast coast by the weekend. A 
cold front should be approaching by late in the period...but appears 
it will be far enough west to not bring any precipitation into the area 
until after the end of the forecast period. Dry weather and above 
normal temperatures will return next weekend into early next week. 


&& 


Aviation.../18z to 18z/ 


VFR expected through the forecast period. Typical Lower Valley 
locations may see an hour of high end MVFR light fog near sunrise 
tomorrow morning. Otherwise...southerly gradient kicks in Tuesday 
ahead of approaching frontal system. 


&& 


Jkl watches/warnings/advisories...none. 


&& 


$$ 
Short term...wjm 
long term...wjm 
aviation...ray