566
FXUS63 KJKL 022248
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
548 PM EST Tue Dec 2 2025

.KEY MESSAGES...

- Spotty light precipitation will wind down in the southeastern
  counties early this evening.

- Drier and colder weather will be in place for the middle of the
  week. Temperatures will average between 5 and 10 degrees colder
  than normal.

- Light snow is possible Thursday night into Friday morning before
  any precipitation changes to rain.

- The pattern will turn active again towards the weekend with
  additional chances of precipitation.

&&

.UPDATE...
Issued at 548 PM EST TUE DEC 2 2025

Raised overnight low temperatures a couple of degrees as extensive
low clouds and moisture should keep temperatures from falling as
much as what the NBM has predicted. Nevertheless, it will still be
a cold sub-freezing night across eastern Kentucky. Also added a
bit more fog for the ridges where the low clouds may intersect
the tops of the plateau across the area.

Taking a quick look at the forecast for Wednesday, there are
suspicions that extensive low clouds will linger longer through
the daytime hours than currently forecast, which would have a
detrimental effect on the forecast high temperatures, especially
across the northern and central parts of the forecast area.


&&

.SHORT TERM...(This evening through Wednesday night)
Issued at 400 PM EST TUE DEC 2 2025

Late this afternoon, a broad trough extended from the Hudson Bay
vicinity into much of the Conus downstream of an upper level
ridge centered in the eastern Pacific. A shortwave trough
extended from the eastern Great Lakes to mid OH Valley and
Southern Appalachians that was moving within that trough.
Additional shortwaves moving through the trough extended from
near the Ontario and Manitoba border into the Dakotas while
another shortwave was moving across the Four Corners/Co Rockies
vicinity with another over sections of the Great Basin. At the
surface, an area of low pressure was centered off the coast of the
Delmarva with the cold front trailing into FL to the Gulf.
Meanwhile a sfc ridge of high pressure was centered in the
Arklatex vicinity and building toward the TN and Lower OH Valley
regions. Another low pressure in advance of the shortwave near
the Ontario and Manitoba borders was centered near the border
between the Dakotas and MN with a warm front south into the
Central Conus and a cold front trailing into MT. Another sfc low
associated with the shortwave currently in the Four Corners region
was beginning to organize in the northeastern NM/TX and OK
panhandles vicinity. Locally, some spotty light flurries and/or
drizzle and perhaps spotty freezing drizzle above 2000 feet was
likely occurring at this point in the counties nearer to the VA
border. Elsewhere, cloud cover has persisted and temperatures
have risen very little throughout the day.

This evening and Wednesday, the shortwave trough currently
departing to the east of the area will move further norht and east
with a trend of 500 mb height rises expected overnight into
Wednesday morning. As this occurs, the sfc ridge of high pressure
will build into the Gulf coast states to OH and TN Valley regions.
Meanwhile, further north and northwest, the shortwave trough
currently near the Ontario and Manitoba border to Dakotas will
rotate to James Bay to the Central Great Lakes while the
associated sfc low tracks into Quebec and the trailing cold front
extends into the Great Lakes to mid MS valley to Plains. As this
occurs, the southern sfc system should track to eastern sections
of TX. For Wednesday night, the shortwave in Canada to the Great
Lakes should move deeper into Quebec to the St Lawrence Valley to
eastern Great Lakes while the cold front in advance of it nears
the Northeast to Lower OH Valley region.

Despite a trend of mid level height rises and sfc high pressure
building into the region tonight, guidance has low level moisture
and clouds being slow to erode though some breaks may begin to
occur as the night progresses. Moisture should become too shallow
for any light precipitation even near the VA border this evening.
Otherwise, if breaks in the clouds or partial clearing were to
occur, fog or evening freezing fog could become a concern. Also,
with some fairly low cloud bases as present and some subsidence
and some cooling during the evening into the night some stratus
build down fog is not out of the question.

High pressure will lead a clearing trend for Wednesday along with
drier weather and milder temperatures. Clouds will increase
Wednesday night as the next cold front begins to near the OH
Valley and moisture increases as mid and high levels. However,
with high pressure starting to shift east of the area, a moderate
ridge/valley temperature split is anticipated with lows likely to
occur around 06Z before mid level moisture and clouds increase.
Moisture will be limited late Thursday night, but there may be
deep enough mid level moisture or seeder feeder for some flurries
or spotty light snow north of the Mtn Parkway. More southern
locations should remain dry for Wednesday night. Lows should range
through the 20s.

.LONG TERM...(Thursday through Tuesday)
Issued at 241 PM EST TUE DEC 2 2025

The forecast period commences with surface high-pressure dominance,
yet aloft, two distinct synoptic-scale waves are poised to govern
the weather through the initial segment of the forecast. The first
is a minor shortwave trough currently ejecting from the Great Lakes,
which is expected to have negligible impact on the forecast area.
The more significant feature is a potent upper-level trough moving
eastward from the Rocky Mountains at the start of the period.

This feature is forecast to track swiftly eastward along the Red
River Valley through Thursday before lifting northeastward into the
Tennessee Valley by Friday morning. As this trough lifts, the
precipitation shield will encroach from the south, beginning as all
snow but rapidly transitioning to a wintry mix as the elevated warm
layer advects northward. Both the GEPS and GEFS ensemble
probabilities indicate the highest threat for freezing rain over
Tennessee, with approximately a 10% chance across the southernmost
tier of counties in the forecast area. Nevertheless, as the surface
cyclones warm front progresses northward throughout the day, the
wintry precipitation will transition to predominantly rain before
the system departs the region by late Saturday morning. A brief
period of a wintry mix remains possible on the backside of the
departing system as cold-air advection returns to the region.

Model confidence begins to degrade heading into the remainder of the
weekend. Some agreement exists between the ECMWF and GFS models, but
the ECMWF favors a quasi-zonal flow pattern through the weekend
ahead of another shortwave, whereas the GFS accelerates another fast-
moving shortwave with the CWA remaining under a southwesterly flow
regime through the duration of the weekend. Long-term guidance
returns to better continuity with the development of the latter
shortwave. At the surface, this translates to the return of surface
high-pressure for the weekend, but increasing PoP is expected late
Sunday afternoon with the approach of the trough. This system
appears likely to bring another round of wintry mix, as critical
thickness contours, forecast soundings, and ensemble probabilities
suggest the CWA could experience the full spectrum of winter
precipitation types through the conclusion of the forecast period.

The overall period will be punctuated by intervals of surface high
pressure interspersed with episodes of rain and wintry mix.
Temperatures are forecast to remain slightly below average
throughout the period.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 107 PM EST TUE DEC 2 2025

A mixture of IFR and MVFR was reported at issuance with upslope
flow between a departing area of low pressure and high pressure
gradually building in from the central Conus. Spotty light
precipitation likely a mixture of snow, drizzle, and perhaps
spotty freezing drizzle lingers south of the TAF sites. That
precipitation should end over the first 2 to 5 hours of the
period, but low level moisture will linger for much of the period
and if and or when any clearing does take place, fog with some IFR
reductions may develop. In addition, as the night progresses,
some stratus build down fog with IFR or lower vis is also
possible for KJKL, KSJS, KSME, and KLOZ. Otherwise, mainly a
mixture of MVFR and IFR ceilings are anticipated areawide through
about 09Z, before high pressure building in leads to some
scattering of low clouds from that point through the end of the
period.

Winds will average northwest at 5 to 10KT to begin the period an
then become light and variable after 23Z.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

UPDATE...CMC
SHORT TERM...JP
LONG TERM...VORST
AVIATION...JP