Area Forecast Discussion
Issued by NWS Jackson, KY

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FXUS63 KJKL 010556
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1256 AM EST Thu Dec 1 2016

.UPDATE...
Issued at 1256 AM EST THU DEC 1 2016

With rain having exited eastern Kentucky, will continue to keep an
eye on stratus moving across northern to portions of central
Kentucky. Have seen a recent slight shift to the north with this
cloud deck, so this would point to locales in the Cumberland
Valley and southeastern Kentucky cooling a few more degrees than
previously thought this morning. Will continue to monitor this and
adjust temperatures if needed.

&&

.SHORT TERM...(This evening through Thursday night)
Issued at 345 PM EST WED NOV 30 2016

As of mid afternoon, a mid level ridge was in place from the
Caribbean to the Bahamas while another ridge was located over the
Eastern Pacific. A broad area of mid level troughing extended from
much of the Western Conus into the Central Conus. Within this
trough a closed low was nearing the Western Great Lakes while a
shortwave trough was nearing the Lower OH Valley. At the sfc, an
area of low pressure was over the Great Lakes region with a cold
front extending south through the Ohio Valley and into the TN
Valley. At this time, the front is moving further into Eastern KY
with the main band of much needed rain finally shifting into WV
and VA. Another sfc trough and associated band of low and mid
clouds associated with the returns over Central Ky is also
approaching.

The closed upper level low should meander to the Northern Great
Lakes/Eastern Ontario region with the sfc low moving further to
the north and east. The shortwave nearing the Lower OH Valley at
this time will work across the area through this evening although
another weak shortwave moving around the closed low will pass
through the Lower OH Valley and approach the Great Lakes tonight.
The core of the coldest air aloft, with 850 mb temperatures around
-3C to -5C moving across the area late tonight and into the day on
Thursday. The cold advection aloft will steep lower level lapse
rates and additional isolated to scattered showers will be
possible as the lead shortwave moves through. Colder air will work
in at the lower levels, but moisture will linger near 850 and
below and the colder temperatures aloft should promote a
considerable amount of low clouds tonight and lingering into the
day on Thursday. Surface high pressure over the Southern Plains
will build northeast toward the TN and OH Valleys tonight.

Mid level heights are expected to rise on Thursday into Thursday
evening as the closed low departs further west and a western
trough digs toward the Four Corners region. Meanwhile sfc high
pressure is expected to build across the southern states and into
the Lower OH Valley and Southern Appalachians. Low level moisture
is expected to linger and a rather substantial cu and stratocu
field should be in place or develop on Thursday and this combined
with the rather cold 850 mb temperatures should lead to below
normal temperatures for Thursday. During this time, the high will
usher drier air into the region and some clearing or partial
clearing should support temperatures dropping off to near the
freezing mark if not the upper 20s on Thu night.

.LONG TERM...(Friday through Wednesday)
Issued at 259 PM EST WED NOV 30 2016

There will be plenty more opportunities for rain through the long
term period as an active weather pattern sets up across the CONUS.
We start out with zonal flow aloft but this transitions to
southwesterly flow next week as a cutoff low over northern Mexico
ejects northeastward and is followed by the establishment of a
deep and broad trough out west, with ridging up the East Coast.

High pressure at the surface will control our weather through
Saturday with dry but chilly conditions expected. A weak ripple in
the flow aloft passing across the Ohio Valley combined with
diffluence aloft to our southwest results in a weak overrunning
event Saturday night into Sunday. Light precipitation will
overspread the area from southwest to northeast Saturday night.
Temperatures will be borderline for rain or snow, and will include
both at the onset, but precip should become all rain during the
day Sunday as temperatures warm into the 40s.

Models have trended drier Sunday night as our overrunning event
quickly pushes off to the east. The next solid chance for precip
then arrives late Monday into Tuesday morning as the upper low
over northern Mexico opens up and ejects northeastward. This
should be all rain with temperatures well above freezing. We will
then maintain a small rain chance Tuesday afternoon through
Wednesday as models are varying with their timing of another
weather maker entering the scene from the west. This last system
still looks poised to bring some cold air south into our region
to end the work week.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1256 AM EST THU DEC 1 2016

A deck of stratus clouds moving across northern to portions of
central Kentucky will continue to track eastward tonight. Have
seen a recent slight shift northward with this deck, suggesting
LOZ/SME and possibly JKL may maintain VFR conditions. SJS/SYM
stand a better chance at seeing degradation to MVFR ceilings into
mid-late Thursday morning. Clouds should lift and break up by late
morning through the afternoon as west/southwest winds increase to
5-10 knots with gusts of 15-20 knots. These winds will diminish by
late afternoon/early evening to less than 5 knots as VFR
conditions persist.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...GUSEMAN
SHORT TERM...JP
LONG TERM...ABE
AVIATION...GUSEMAN


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