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fxus63 kpah 222040 

Area forecast discussion
National Weather Service Paducah Kentucky
240 PM CST Fri Nov 22 2019

Short term...(tonight through Sunday night)
issued at 240 PM CST Fri Nov 22 2019

A surface low pressure wave will move northeast along a frontal
boundary tonight, passing across middle Tennessee on Sat morning.
This low will produce a chilly northeast wind flow. Since the 850
mb low center will pass to our northwest, the northeast wind flow
will be very shallow. This will result in areas of overrunning
light rain/drizzle, even apart from the contribution of an upper
level shortwave late tonight. Although pops will be very high,
rainfall amounts will be mainly one-quarter inch or less.

Light rain will taper to drizzle during the day Saturday as the
upper-level shortwave moves off to our east. Under the persistent
low-level inversion, low clouds will hang tough all day. The
northerly winds and dense overcast will keep temps nearly steady
in the lower to mid 40s through the day.

Clearing appears likely Saturday night as deep-layer northwest
flow breaks up the inversion. Low level winds will decrease,
allowing temps to radiate down to about freezing in most places.
This will be a favorable setup for dense fog if clearing occurs
early at night. Due to the potential for clouds to linger much of
the night, will refrain from mentioning fog at this time.

Sunday and Sunday night should be mostly clear under drier
westerly winds. Under the influence of high pressure over the
lower Mississippi Valley, highs will struggle to reach 50 Sunday
even with the sunshine. Lows will fall back into the 30s Sunday

Long term...(monday through friday)
issued at 240 PM CST Fri Nov 22 2019

Zonal flow aloft and a developing low level flow will start out next
week, with temps on the mild side. The medium range models were in
reasonable agreement with their depiction of a fast-moving and
strengthening shortwave and its attendant surface low moving out of
the Pacific northwest and crossing the pah forecast area on Tue.
Robust low level moist flow (40+ knots at 850 mb) ahead of the
surface low Tue morning should provide a fairly short interval of
rainfall before the surface wind shift occurs Tue night. As the
surface low bumps up against a southeastern Continental U.S. Ridge, breezy
conditions are expected in our region Tue, and also Tue evening as
skies begin to clear. Gusts 35 to 40 mph are possible.

The GFS was quicker than the European model (ecmwf)/CMC at shunting deep moisture
farther east for Wed night as a large mid level low begins to dig
into the southwestern Continental U.S. Flow, setting up a longwave trof-
West/Ridge central/trof east pattern across the Continental U.S.. overall, the
deterministic solutions suggested that Wed night/Turkey day will be
mostly dry, but cloudy for US. The National blend contained minimal
pops for the Wed through Thu evening time period, which seemed
reasonable with the models' difficulty with pcpn timing in this type
of mid-to-late week flow pattern. Fri (day 7) could be a little


issued at 240 PM CST Fri Nov 22 2019

Gradual clearing of the low clouds has been taking place from
north to south through the afternoon hours. It still remains to be
seen whether clearing will cross the Ohio River before nightfall.
As of 20z, VFR conditions are still forecast to reach kpah and
kowb by this evening.

Another period of rain is forecast later tonight into Saturday as a
low pressure center passes to our southeast. Conditions will
deteriorate to IFR once again by Saturday morning.


Pah watches/warnings/advisories...


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