424 
fxus61 Kiln 080233 
afdiln 


Area forecast discussion 
National Weather Service Wilmington Ohio 
1033 PM EDT sun Sep 7 2008 


Synopsis... 
high pressure over the Central Plains will build into the Ohio 
Valley tonight. The high will move east of the region on 
Monday...as a deepening surface low moves into the Great Lakes. 
A cold front trailing from the low will swing through the region 
late Monday and early Tuesday. 


&& 


Near term /until 6 am Monday morning/... 
surface high pressure over Illinois to build across Ohio Valley overnight. 
Diurnal cumulus which developed today has dissipated yielding clear skies. 
Isentropic lift ahead of next short wave has lead to the development of 
middle level ceilings into the middle MS valley. These middle level clouds will 
spread into the west late tonight before lifting north on Monday. 
Had made minor adjustments tweaking lows up slightly tonight. 
Otherwise...just freshened up forecast for current conditions. 


&& 


Short term /6 am Monday morning through Tuesday night/... 
surface high will be fast to move east of the area on Monday bringing a 
return southerly flow to the Ohio Valley. With continuous warm air advection 
through the day...felt warmer mav numbers were the way to go for 
maximum temperatures. 


Front still expected to quickly cross the area late Monday night 
and early Tuesday as deepening surface low moves across the Great Lakes. 
NAM and GFS indicate a good deal of low level convergence along 
and ahead of the front as low level jet intensifies overnight. 
This jet brings in a surge of higher Theta-E air ahead of the 
front...so elevated instability should be in place. Increased probability of precipitation to 
50 across the northeast 2/3 of the County Warning Area Monday night into Tuesday...which 
may need to be increased even further. Strong cold air advection behind the 
front will bring below average temperatures on Tuesday...and felt cooler met 
numbers had a better handle on the depth of the cool airmass 
behind the front for Tuesday and Tuesday night. 


&& 


Long term /Wednesday through Sunday/... 
surface high pressure will slide off to the east through the 
middle part of the week. This will provide for a gradual warm up 
Wednesday into Thursday as warm air advection pattern develops across the area. 
Both the 12z GFS and 00z European model (ecmwf) are then pushing a middle level short 
wave through the region Thursday night into Friday...resulting in 
the next chance of precipitation. 


Some minor differences between the two models for Friday night into 
Saturday...but both are hinting at a bit of a middle level ridge quickly 
transversing the area before trough begins to establish itself 
across the Mississippi vally through the end of the weekend. Will 
therefore just carry a silent 20 pop in the grids for Friday nigh 
and Saturday and then bring a better chance of precipitation back in for 
Sunday. 


With the possibility for a fair amount of clouds and some 
precipitation...will generally go a little cooler than guidance 
for highs and a little warmer with lows through the last part of 
the long term period. 


&& 


Aviation /02z Monday through Friday/... 
surface high pressure over the middle MS valley to build east through 
the Ohio Valley tonight. Scattered/broken diurnal cumulus which developed will 
dissipate through the evening leaving mostly clear sky conditions. 
Flow backs late tonight/Monday ahead of approaching short wave dropping 
into the middle MS valley. Isentropic lift will allow middle level clouds 
to develop and spread across the taf sites late tonight/Monday before 
lifting north. These clouds should limit the fog formation. Have 
mention of MVFR visibilities late tonight at kcvg and Kiln with IFR visibility 
restriction at kluk. Surface winds on Monday will shift from easterly 
to more southerly. 


Outlook...showers and thunderstorms are possible Monday night 
into Tuesday. 


&& 


Iln watches/warnings/advisories... 
Ohio...none. 
Kentucky...none. 
In...none. 


&& 


$$ 
Synopsis...Arkansas 
near term...hawblitzel 
short term...hawblitzel 
long term...jgl 
aviation...Arkansas