967
FXUS63 KJKL 031230
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
730 AM EST Wed Dec 3 2025

.KEY MESSAGES...

- Drier and cold weather will persist through Thursday.

- Wintery precipitation is possible late Thursday night into
  Friday morning, with the greatest chances in Southeastern
  Kentucky.

- The pattern will remain active through early next week, although
  long term forecast confidence is low.


&&

.UPDATE...
Issued at 730 AM EST WED DEC 3 2025

Under extensive cloud cover, temperatures did not bottom out
quite as low as was forecast, and the starting point for this
morning has been adjusted upward. It`s also observed that the
cloud layer has become is so thin that high terrain is poking
above it now. Black Mtn. is seen with a tiny break in clouds in
satellite imagery, as is some of the high terrain in WV. It will
be interesting to see what transpires as the overcast erodes, and
it is probably safe to say that it will differ from what is
forecast.

&&

.SHORT TERM...(Today through Thursday)
Issued at 245 AM EST WED DEC 3 2025

Shallow low level moisture lingers in the wake of Monday night`s
weather system, with cold air advection in upslope flow helping to
keep it trapped beneath an inversion up to this point. This has
kept low clouds socked in. The clouds extend all the way west to
IL, MO, and AR early this morning, near the surface ridge. The
high will shift east today and cold air advection will ease. Along
with minimal heating (albeit just about the weakest solar
insolation of the year), this should finally allow clouds to break
up. However, timing is still very uncertain. Have used a gradual
decrease in clouds due to the uncertainty in timing, when in
reality it may be much more abrupt whenever it happens in any
given location.

Assuming clearing happens by tonight, the night should start out
relatively clear, along with light winds as the high center passes
over. This should allow a quick drop in temperatures after sunset.
A large lobe rotating through a mean upper trough over eastern
Canada will support another cold front to drop south and approach
us from the north overnight, reaching near the Ohio River by dawn.
Clouds will increase overnight as the front nears, slowing our
drop in temperatures.

Some light precip could occur to our north with the front.
However, the front will be running out of available moisture as it
drops south, and we shouldn`t see anything more than clouds with
its passage on Thursday. The clouds and cold fropa will hold max
temps down.

.LONG TERM...(Thursday night through Tuesday)
Issued at 446 AM EST Wed Dec 3 2025

Active weather looks to continue throughout the long term forecast
period, but diverging model solutions continue to limit forecast
confidence. The progressive flow pattern aloft favors seasonably
cool temperatures and periodic precipitation chances, but the
various pieces of currently-available forecast guidance resolve
different positioning and timing details with each individual
disturbance. Thus, it remains difficult to determine p-type and
accumulation details, especially later on in the forecast period.

When the forecast period opens on Thursday evening, an upper level
trough will be propagating through the southern CONUS. By Friday
morning, that trough axis will reach the Tennessee Valley as a
southern stream surface cyclone develops over the Gulf Coast. That
low pressure system should then lift northeast towards the Carolinas
throughout the day on Friday, and the northern extent of its
precipitation shield could clip Kentucky. Some forecast guidance has
recently trended north with this system, and precipitation chances
accordingly return to the forecast early on Friday morning. The
antecedent airmass will be cold enough for wintery precipitation
(overnight lows in the 20s), but this system will have to work to
overcome the existing dryness. LREF Grand Ensemble data signals that
the airmass ahead of the system on Thursday night will be between
the 20th and 40th percentiles of climatological PWAT data. Moisture
will begin to advect into column as the parent trough approaches on
Friday, but so will warm air aloft. Guidance disagrees on the
magnitude of this moisture return (the European data continues to be
relatively wetter), but collectively resolves increasing 850mb
temperatures (the Euro is also relatively colder aloft). This
indicates that precipitation types are likely to change in a manner
consistent with a warm frontal passage: an initial period of snow
will switch to freezing rain or a wintery mix as colder air lingers
for longer at the surface on Friday morning. Diurnal warming and
warm air advection will yield surface temperatures well above
freezing in most locations by midday, favoring a plain rain. Some
guidance, including the GFS, keeps the best moisture contained to
the south of the forecast area in the Tennessee Valley, and the
greatest PoPs remain limited to southeastern portions of the
forecast area. The previously-discussed dry air in the column would
likely keep accumulations on the lighter side, but the timing of the
wintery precip could align with the Friday morning commute. Trends
in higher-resolution forecast guidance will need to be monitored in
the coming days, as their modeled temperature and moisture profiles
will bolster forecast confidence and allow for the dissemination of
more specific details.

The flow aloft is poised to remain progressive and quasi-zonal
behind Friday`s system, but the significant model spread leads to
some artifacts in the baseline NBM data used to populate the long
term forecast grids. For example, forecast guidance has trended
drier from Saturday to Sunday morning, but the time-lagged NBM keeps
slight chance PoPs across the southeastern half of the forecast area
this weekend. Temperatures are forecast to stay seasonably cool,
with highs in the 40s and sub-freezing lows. When these PoPs overlap
with the diurnal low temperatures, the model blend spits out
unrealistic freezing rain chances. There is too much uncertainty to
completely remove these low-end PoPs, but the default p-type grids
were modified to remove the artificial icing.

The precipitation chances in the forecast for Sunday evening and
Monday appear more realistic. Guidance collectively points towards a
better-defined trough approaching the region from the west/northwest
early next week. Models indicate freezing temperatures aloft in this
time frame, but disagree on the evolution of the system and how it
interacts with southern stream moisture. A mix of winter
precipitation types appears likely in this time frame, but the
compounding uncertainty in the long term forecast package makes it
very difficult to provide specific timing or accumulation details.
Interests are accordingly encouraged to stay tuned to future
forecast updates, as models hopefully come closer to a consensus in
the coming days.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
ISSUED AT 629 AM EST WED DEC 3 2025

Low end MVFR and spotty IFR ceilings prevailed across the area
early this morning. The low overcast is forecast to break up
during the day and give way to VFR conditions, but confidence in
the timing is low. Best estimate is that it will be from 16Z-20Z.
Once VFR conditions return, they should last through tonight.
Winds will be light.

&&

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

&&

$$

UPDATE...HAL
SHORT TERM...HAL
LONG TERM...MARCUS
AVIATION...HAL