Area Forecast Discussion
Issued by NWS Paducah, KY

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FXUS63 KPAH 230203

803 PM CST Mon Dec 22 2014

Issued at 803 PM CST MON DEC 22 2014

With this interim forecast update, removed prior first period
(tonight) reference and adjusted PoP`s, Weather, and other
sensible weather elements to reflect periodic rain chances for the
remainder of the first period.


.SHORT TERM...(Tonight through Wednesday night)
Issued at 237 PM CST MON DEC 22 2014

Complicated forecast on tap for the latter part of the short term
period with models not in the best agreement, so forecast confidence
not that good.

A storm system digging southeast across the northern plains will
push a cold front across our region tonight. In the meantime strong
warm air advection and plenty of moisture should continue to
generate rainfall across the area.

There may be a lull in precipitation chances late tonight into
Tuesday morning if we get dry slotted in the wake of the front, but
unfortunately it won`t last long. As a lobe of the parent H5 low
digs southward across the plains, it will induce a surface low/wave
on the front and bring another surge of moisture and elevated
precipitation chances back across the region Tuesday afternoon and
Tuesday night.

The most complicated part of the forecast comes on Christmas
Eve, and as mentioned above, models not in good agreement. On
Wednesday a huge area of moisture/wrap around precipitation will be
pulled across the area with the surface/upper low couplet. In the
process, the deeper cold air will begin to filter into the region.
The timing of the arrival of the colder air and associated QPF
varies considerably between models. If the NAM12 were to pan out,
virtually everyone in our CWA would get snowed upon. If the SREF
were to verify, there would be little to no accumulation at all. The
GFS and ECMWF solutions fall somewhere in the middle, so leaned that
way til we see the whites of its eyes and/or subsequent model runs
come into better agreement.

The down side to any snow accumulation will be the antecedent
conditions where temperatures are concerned, ie the ground and
roadways are and will be fairly warm at the onset of snow. Long
story short, have light snow amounts over our far western counties
Wednesday morning, then less than an inch generally north and west
of a line from Fairfield Illinois to Van Buren Missouri Wednesday
afternoon. As the last of the moisture/wrap around QPF exits the
region Wednesday night, there could be minor snow accumulations
over the far northeast sections of our CWA during the evening.

.LONG TERM...(Thursday through Monday)
Issued at 237 PM CST MON DEC 22 2014

High pressure over the southeast U.S. will provide the PAH forecast
area with dry conditions and south to southwest winds Thursday into
early Friday.  Temperatures will be unseasonably warm with highs
Christmas day in the middle to upper 40s, and Friday in the upper
40s to lower 50s.  Lows Christmas night will be in the middle to
upper 30s, which will be around 10 degrees above normal.

By Friday afternoon, the forecast becomes more challenging, and gets
more confusing through the weekend.  Both GFS and ECMWF bring a weak
cold front through the region late Friday into Friday night, with
GFS the fastest with its passage.  Went with chance pops for rain
showers across the entire PAH forecast area Friday night, mixing
with snow for all but west Kentucky after 06z Saturday.  For the
rest of the weekend, GFS builds in high pressure and keeps our area
dry and near seasonal.  ECMWF brings a surface low just southeast of
the PAH forecast area by 12z Sunday, producing widespread
precipitation mainly Saturday night into early Sunday.  Consensus is
to lean toward the ECMWF, but due to lower confidence, kept pops in
the chance to slight chance categories for now.  Colder air
infiltrating the area would keep us in a rain/snow mix across our
northern half of counties on Saturday, with a rain/snow mix across
our entire area Saturday night.  For Sunday, continued a slight
chance of a rain/snow mix only across our eastern half of


Issued at 615 PM CST MON DEC 22 2014

IFR/Low IFR cigs should take over all sites between 00z and 06z
this evening, along with MVFR vsbys in br and -shra/dz. Conditions
may improve into the MVFR category 14-17Z Tue, but would probably
be lower end 1-2K ft range.




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