658 
fxus63 kpah 131252 
afdpah 


Area forecast discussion 
National Weather Service Paducah Kentucky 
752 am CDT Monday Oct 13 2008 


Update... 
discussion for 12z Monday routine taf issuance. 


&& 


Aviation... 
for current forecast...tried to consolidate tafs for primary 
ceiling and winds throughout the period. Guidance is suggesting a 
broken/overcast cloud deck across each of the taf sites through 
nearly the entire forecast period. This solution may be overly 
pessimistic...so later forecast shifts may need to refine and 
adjust prevailing cloud cover groups. 


For kpah...had to make an initial correction prior to valid time 
of the taf to account for a significant break in the stratocumulus 
through at least 13z. 


&& 


Previous discussion... /issued 248 am CDT Monday Oct 13 2008/ 


Discussion... 


A large high pressure system at the surface and aloft will remain 
anchored over the southeastern states into the middle of the week. 
The 500mb high pressure center will shift from east Kentucky south to Georgia 
through Wednesday. Soundings indicate a dry air mass column across the forecast area 
with the exception of a layer of moisture centered around 5k feet 
until early Tuesday...after which time increasing moisture is evident at 
all levels...especially below 15k feet. The southeast corner of the forecast area is a 
bit of an exception as moisture increases are more limited and/or 
delayed here...although for today 850mb moisture is just as 
pronounced. 


Given the persistence/strength of the ridging will back off on rain 
chances slightly for Tuesday...but then increase over previous package 
for Wednesday...at least across the northwest part of the forecast area in closer proximity 
to the approaching surface frontal system. The surface front will 
show limited southeast progress until a 500 mb shortwave moves east from 
the Central Plains on Wednesday. The GFS is a bit faster with the surface 
front...having it exit southeast of the forecast area by Thursday am whereas the European model (ecmwf) 
timing is more into Thursday afternoon or evening. For now will not 
introduce or extend probability of precipitation for Thursday night...but if later trending is 
maintained this may be needed...at least for the S or southeast portion of 
the forecast area. 


Instability is limited with this system as reflected in the latest 
Storm Prediction Center outlooks with only general thunder across southeast MO and SW Illinois for 
Tuesday/Tuesday night. Likewise rainfall totals will likely be minimal/ 
generally below 1/4 inch total given the absence of deep moisture 
and limited dynamics. 


For Friday through the weekend...high pressure will build into the 
forecast area behind the surface cold front providing seasonably cool 
temperatures and dry conditions. 


Temperature forecasts from previous package will be maintained...which are 
closest to...yet above the warmer mav MOS values. Aforementioned 
moisture will limit maximum temperatures today...however will have to watch 
closely as airmass could otherwise support temperatures as warm as Sunday 
values which were only a degree or two below record values. 




Aviation... 
southeasterly low level flow on the back side of a high pressure 
ridge will continue to pump increasing amounts of moisture and cloud 
cover into the forecast area through Columbus day. VFR ceilings will 
persist over the kcgi and kpah taf sites through Monday...and may 
even lower to high end MVFR late tonight and early Monday. Clouds 
will overspread kevv and kowb late tonight...but ceilings there 
should remain VFR. Light southeast winds tonight will pick up close 
to 10 knots on Monday. Where intervals of sunshine promote mixing... 
gusts may range as high as 15 knots. With the increase in sky cover 
and sustained light winds overnight...fog should not be a problem... 
even at kcgi. 


&& 


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


$$ 


Short/long term....Shanklin 
aviation...Smith