620 
fxus61 krlx 091931 
afdrlx 


Area forecast discussion 
National Weather Service Charleston WV 
231 PM EST Friday Jan 9 2009 


Synopsis... 
warm front in our vicinity...lifts a bit north...into southern Ohio 
and to near WV/PA border Saturday. Low pressure passes late 
Saturday. Colder air Saturday night into Sunday. 


&& 


Near term /through tonight/... 
tough hourly temperature forecast tonight - with that challenge 
continuing on Saturday for our short term forecaster. Tried to drop 
temperatures this evening...then start rising temperatures...first 
over the high terrain around lnp to bkw then into heights-crw region 
during the predawn hours. The 925 mb inflow ahead of surface 
wave...into the frontal zone...increase to 40 to 50 knots by 12z 
Sat over eastern Kentucky and southern WV. 


Slowed down the chance pop reaching ln-bkw-ekn...so completely dry 
overnight in our eastern counties. 


Was a bit less energetic on the snow across interior southeast 
Ohio...thinking more sleet and freezing rain in the wintry mix there. 
With the snow concentrated further north. 


No reason to change the current Winter Weather Advisory where 
we feel strong enough for the freezing rain. May need a west-southwest 
for a strip of counties further south in southeast Ohio into northwest WV for a 
short duration Saturday morning. Will leave "some work" for the 
evening and graveyard shifts since have temperatures on either side 
of 32 and my tight pop gradient is during that time. 


&& 


Short term /Saturday through Monday/... 
models continue to indicate a area of low pressure will move across 
the Saturday into Saturday night. Ahead of this feature...warm air 
will stream northward. This will result in rain across the southern 
two-thirds of the County Warning Area...with freezing rain possible across the far 
north at the beginning of the period. As the precipitation spreads 
eastward...there could be a few hours of freezing rain in the 
Greenbrier valley. This area may need a Freezing Rain Advisory for 
a few hours early Saturday. 


Expect temperatures to continue to warm Saturday morning...with most 
locations seeing liquid rain by noon. 


The cold air aloft will being to filter in from northwest after 18 
UTC...which should allow the precipitation to change back to snow 
across the northwest counties by 00 UTC Sunday. 


As the low pushes off to the east late Saturday and Saturday 
night...the precipitation will change back to snow as it ends from 
the west. 


High pressure building in Sunday will result in scattered snow 
showers in the mountains...with dry conditions across much of the 
remainder of the area. The snow should then end by 00 UTC 
Monday...as high pressure takes control. 


The high should remain in control of the weather through Sunday 
night...resulting in dry conditions as well as below normal 
temperatures. 


Another system will approach from the west on Monday...bringing 
another chance of wintry weather to the area. 


Temperature guidance was generally in line with previous temperature 
forecast and appears reasonable...so only some minor tweaks were 
made. 


&& 


Long term /Monday night through Thursday/... 
northwest flow will become predominant through the period with a 
series of Canadian clipper systems pushing through middle level flow. 
Each clipper brings a reinforcing shot of cold air...so that by the 
end of the period...850h temperatures will dip down to around the -25c 
range. 


Both GFS and European model (ecmwf) show slight differences in timing each of these 
features across. Therefore...stayed close to HPC guidance in terms 
of probability of precipitation and temperatures...which generally followed the European model (ecmwf) and European model (ecmwf) 
ensembles. This pairing has show the best run to run consistency 
with time. 


With overland trajectory of systems...and cold air environment... 
moisture amounts will be limited. However...with cold air in 
place...all precipitation will be of the frozen variety through the 
extended period. Therefore...there will be increasing chances for 
some light snow accumulation as the upcoming week progresses. 


&& 


Aviation /20z Friday through Wednesday/... 
last of the stratocumulus should evaporate vicinity ckb at start of 
this period. Otherwise broken to overcast middle deck at 6 to 10 thousand feet 
this afternoon mainly north of heights-crw-bkw line. Have a chance of light 
snow reaching the ground north of pkb-ckb corridor for a few hours 
20-23z. 


Clouds at 3 to 5 thousand feet broken/overcast increasing after 06z...reaching 
heights-pkb 06z-09z...crw-ckb 09-13z and mountains by 15z. Have rain 
for hts-crw-bkw-ekn...with possible freezing rain at the start for 
pkb and ckb. See tafs for precipitation timing. 


Aviation outlook /beyond 18z Saturday/... 
IFR possible Saturday afternoon and Saturday night in ceilings and 
precipitation. Rain changing to...and diminishing to...snow showers 
overnight Saturday night. 


&& 


Rlx watches/warnings/advisories... 
WV...none. 
Ohio...Winter Weather Advisory from 3 am to 7 PM EST Saturday for 
ohz066-067. 
Kentucky...none. 
Virginia...none. 


&& 


$$ 
Synopsis...ktb 
near term...ktb 
short term...jsh 
long term...kmc 
aviation...ktb