Area Forecast Discussion
Issued by NWS Paducah, KY

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FXUS63 KPAH 122106 CCA

Area Forecast Discussion
National Weather Service Paducah KY
302 PM CST Sun Nov 12 2017

.SHORT TERM...(Tonight through Tuesday night)
Issued at 301 PM CST Sun Nov 12 2017

A weak cold front/surface wind shift was well on its way across
the PAH forecast area this afternoon as a mid level trof axis
approached from the northwest. Lingering pcpn has ended in the
east. Some breaks in the clouds may occur for a few hours this
afternoon, mainly over parts of southeastern MO/western KY, but
should fill back in as the aforementioned trof creates a bit of
lift. Generally light surface winds should be out of the north to
northwest everywhere by around nightfall. As northwesterly flow
aloft and high surface pressure move into our region overnight, a
general reduction in cloudiness is expected to begin. Mon and Mon
night will be mostly clear and relatively cool, followed by a
modest warming trend for Tue/Tue night.

Tue night, another low-amplitude mid level shortwave is progged by
the models to move through the Dakotas and upper Midwest, dragging
a cold front eastward toward the PAH forecast area. As a result,
winds will gradually gain a more southerly component Tue/Tue
night. Clouds are forecast to increase from west to east Tue
night, with an accompanying increase in PoPs for showers after
midnight for most of the region. At this time, indications are
that instability will not be enough for lightning activity before

.LONG TERM...(Wednesday through Sunday)
Issued at 301 PM CST Sun Nov 12 2017

Confidence in the Wednesday forecast remains fairly high. The models
are in good agreement moving a front through during the day, with
categorical PoPs for showers maintained, along with a continued
slight chance of thunder. The instability is weak, and difficult to
find until lifting parcels from h8 and especially h750. Mid level
lapse rates aren`t too bad either. The chances will end quickly by
early evening, with mainly dry weather Wednesday night through
Thursday morning. Left a token slight chance in along the TN/AR
border so we don`t discount the GFS completely. However the last few
runs of the ECMWF/CMC are definitely trending dry all areas. In the
afternoon, will maintain a low chance PoP over SEMO, probably not
much until dark as again, the ECMWF/CMC are slower to push the warm
front and associated moisture and lift back northeast into the area.
Thursday night, will gradually spread the chance of showers
northeast across the CWFA, with the front pushing northeast into the

Same timing and confidence problems exist for the Friday through
early Saturday time frame. The 12z ECMWF and UKMET have slowed down
even more, suggesting the front may not move through until early
Saturday. This would leave Friday and early Friday night warm
sector, with lower PoPs in the wake of the warm front. The GFS
remains slightly faster though it slowed as well, as does the CMC
(not as fast). We have seen the EC/UKMET solutions slow down too
much in the past only to speed back up with time. Think a middle
ground approach remains the way to go, with just a trend slower.
Therefore once again, the ridiculous categorical blend PoPs here and
there are simply not appropriate for a low confidence forecast that
could shift 6-12 hours either way Day 6 and beyond, until we get
closer to the event. Therefore just high chance PoPs again Friday.
Went low end likely Friday evening, mainly to collaborate without
being too far off with other offices. Then we taper off PoPs after
midnight Friday night. Saturday through Sunday remain dry and cooler
in the wake of the front. If the slower solutions hold, Saturday
morning may be in question (not dry). The ensemble mean solutions
from the NAEFS, GEFS and ECENS all support not slowing down as much
as the latest 12z EC/CMC models. Temperatures will be highly tied to
how events unfold. So low confidence call here as well. Went close
to persistence and MOS to minimize the sway. We may be looking at
strong convection with the Friday/Friday night system. Still an
awful lot of question marks at this point.


Issued at 301 PM CST Sun Nov 12 2017

A weak cold front will continue to make its way through the
region today. By nightfall, surface winds under 10 knots will turn
to the north or northwest across the PAH forecast area. Cigs over
southern IL/southwestern IN will remain in the MVFR category
through the evening while the remainder of the region should
generally maintain VFR cigs. However, parts of southeastern MO,
including KCGI, may experience a scattered or even broken stratus
layer (MVFR) during the evening. Cigs should go at least
scattered after midnight, and mostly clear skies are forecast for
roughly the last six hours of the 18Z TAF period.




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