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Area forecast discussion 
National Weather Service Paducah Kentucky
617 am CST Tuesday Dec 1 2015

issued at 611 am CST Tuesday Dec 1 2015

For aviation section only.


Short term...(today through Thursday night)
issued at 329 am CST Tuesday Dec 1 2015

High confidence in a dry/cool short term forecast once light rains
exit the pennyrile of western Kentucky this am.

Cold front has now moved east of the region. There are currently
some light rains just behind the front early this morning, but
they will be exiting soon. Some low clouds will linger awhile
longer today. Clearing line should make its way east through se MO
this morning then farther east in the aftn.

Sfc ridge of high pressure will be building into the region today
and tonight. However, an upper level trof extending south from a
closed low moving east through the Midwest and Great Lakes will
pass through the region on Wednesday. Not expecting any
precipitation with this upper trof, but it could serve to bring
additional clouds, which would keep temps from warming out of the
40s at most locations.

Thereafter, a large dome of chilly high pressure will build in
from the west. Though sunshine should be plentiful by Thursday,
Max temps will probably stay in the 40s once again.

Long term...(friday through monday)
issued at 329 am CST Tuesday Dec 1 2015

The deterministic and ensemble guidance last week suggested the
development of a highly meridional shortwave diving into The Four
Corners area over the weekend and deepening into a closed low Lee of
The Rockies as early as Sunday.

As has been the case with the last couple of systems moving over the
weather forecast office pah forecast area, timing is the key. As these systems move into
the 240 hour range, they are usually a little fast with onset, then
slow down with later runs as model input from satellite and other
remote sensing data refines the movement of these systems over the
Pacific Ocean.

The latest deterministic runs (00z monday) of the GFS (20 km) and
European model (ecmwf) are slowing down the system even further for next Monday and
shearing out the Lee side low as another wave train moves across
the intermountain west.

Rather than flip-flop, mad a slight modification of the model blend
initialization to lower rain chances. The pops still remain in the
chance category on Monday, but are on the low end of the spectrum.
All of the guidance moves the system out of the area by early next
Tuesday, keeping dry weather over the area through next Wednesday.

Temperatures after midnight on next Monday night may be cool enough
for a brief and light flurry production, but evaporative cooling
will be great enough to keep any precipitation as virga
(precipitation aloft).

Otherwise, seasonable temperatures will remain in place for the
extended forecast period.


issued at 611 am CST Tuesday Dec 1 2015

Cold front has now crossed the region. A layer of IFR/MVFR stratus
will clear from west to east across the taf sites this morning,
leaving VFR conditions for the remainder of the period.


Pah watches/warnings/advisories...


short term...GM
long term...Smith

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