Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

277
FXUS63 KJKL 201245 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
745 AM EST Tue Jan 20 2026

.KEY MESSAGES...

- A Cold Weather Advisory remains in effect for the Bluegrass area
  of eastern Kentucky early this morning.

- Temperatures will average 10 to 20 degrees below normal through
  tonight before we briefly warm to above normal at mid week.

- There is a chance for light precipitation - primarily rain - on
  Wednesday and Wednesday night.

- A potentially significant storm system could yield impactful
  snow accumulations this weekend.

&&

.UPDATE...
Issued at 720 AM EST TUE JAN 20 2026

No significant changes were made to the forecast with mainly just
the inclusion of the latest obs and trends for the T/Td/Sky grids.
These minor adjustments have been sent to the NDFD and web servers
along with a freshening of the SAFs and zones.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 525 AM EST TUE JAN 20 2026

09Z sfc analysis shows high pressure pushing into Kentucky from
the southwest. This has kept the skies mostly clear overnight
allowing for good radiational cooling and temperatures on their
way into the single digits for most places. Currently,
readings are running near 10 degrees north to the mid teens in
the far southeast with some colder pockets in the upper single
digits found in many sheltered valley locations. A light breeze
from the west to northwest is driving apparent temperatures toward
zero degrees early this morning. Meanwhile, dewpoints are
generally in the single digits below zero north and between zero
and five above in the south. A Cold Weather Advisory is in effect
north, over the Bluegrass Counties, early this morning while an
SPS covers the rest of the area.

The models, and their individual ensemble suites, continue to be
in good agreement aloft through the short term portion of the
forecast. They all depict the broad and dominant 5h troughing over
much of the continent temporarily relaxing above Kentucky today
with a node of it shifting east. This tilts the mid level flow
more zonal for a brief time into the evening. The pattern then
swings to southwesterly later tonight and into Wednesday in
response to more energy and 5h height falls digging through the
Midwest. Some of the energy associated with this sweeps over
eastern Kentucky by Wednesday afternoon. Again the small model
spread supported using the NBM as the starting point of the
forecast grids with adjustments made to include more terrain
details for temperatures tonight, as well as beefing up the winds
a bit on Wednesday - closer to HRRR gusts. Did also push higher
PoPs into the area Wednesday afternoon per the CAMs consensus.

Sensible weather features a very cold start to the day for most of
the area with only a partial warmup into the afternoon despite
plenty of sunshine. Another mostly clear night and light winds
will set up a ridge to valley temperature difference showing up
through the first part of the night before warmer air advects in
on increasing southwest winds toward dawn. This will bring
temperatures to above freezing by mid morning and just about the
same time some light pcpn moves into the area ahead of a weak cold
front. This warm up will likely change any early patches of light
snow over to scattered rain by afternoon with no impacts
anticipated. Breezy southwest winds that afternoon helps
temperatures reach the mid and upper 40s for the bulk of the area
on Wednesday with a nice, but brief thaw, for the area - ahead of
more Arctic air moving in during the latter part of the week and
setting the stage for increasing probabilities of a winter storm
over the weekend.

The changes to the NBM starting point primarily consisted of
including more terrain details in for temperatures tonight along
with stronger winds ahead of a cold front Wednesday afternoon. Did
also beef up the PoPs per CAMs consensus on Wednesday.

.LONG TERM...(After midnight Wednesday night through Monday)
Issued at 731 AM EST Tue Jan 20 2026

While light precipitation is likely to be ongoing across the
forecast area on Wednesday evening, it is unlikely to produce
significant impacts. However, the cold air advection regime behind
this midweek activity will set the stage for a more impactful winter
storm this weekend. It remains too early to provide details like
exact accumulation amounts and specific precipitation start/end
times with this second system, but the synoptic pattern points
towards a significant winter storm moving across the southern CONUS.
Here in Eastern Kentucky, we look to be positioned firmly on the
cold side of the system as the dynamic ingredients favoring
precipitation come into place. Thus, confidence is increasing that
accumulating snow and bitterly cold temperatures will affect the
forecast area in the Saturday to Sunday time frame. The cold air
will linger through the end of the forecast period on Monday, and
January 2026 is poised to end on a wintery note.

Wednesday night`s precipitation chances are associated with an upper
level shortwave disturbance swinging through the Great Lakes. This
feature`s surface reflection will eject northeast into Ontario
overnight, dragging a weak cold front through the forecast area. The
narrow band of pre-frontal warm air advection and low-level moisture
return that occurred on Wednesday afternoon is expected to yield
thermal profiles favoring rain on Wednesday night. Cold air
advection and wetbulbing could allow a few snowflakes to mix in as
temperatures cool to near freezing on Thursday morning, but little
to no accumulation is expected. Surface winds will shift towards the
west as a post frontal high nudges into the region during the
daytime hours on Thursday. This favors quiet sensible weather, and
temperatures should reach the low to mid 40s on Thursday afternoon
under partly cloudy skies. However, another shortwave disturbance
pivoting through the cyclonic flow aloft is forecast to send a
second cold front into the region on Thursday night. That boundary
will have little to no moisture to work with, and it will likely
stall out to the south in the Tennessee Valley. However, a much
stronger surface high pressure system will nudge into the Midwest
behind that front on Friday, allowing the surface pressure gradient
over the forecast area to tighten throughout the day.

As winds strengthen and shift to a more north-northwesterly
orientation in response to these synoptics, a potent low-level cold
air advection regime will emerge. Temperatures on Friday will be 10-
15 degrees colder than they were on Thursday, and may take the form
of a north-south gradient depending on where the front stalls out.
North of the Mountain Parkway, temperatures will likely struggle to
warm above freezing all day. Further to the south, expect
temperatures in the low to mid 30s. A few pieces of forecast
guidance suggest that a weak disturbance may try to ride the stalled
boundary to our south on Friday. There are low-end PoPs in the
forecast as a result, but expect them to trend downward in
subsequent forecast packages. The better precipitation chances have
been trending later in the weekend, after persistent cold air
advection allows temperatures to tank further overnight.
Temperatures will dip into the lower teens/single digits on Saturday
morning, then struggle to warm above freezing for the rest of the
long term forecast period. Wind chills will be bitterly cold, and we
may approach cold weather advisory criteria.

The forecast guidance suite continues to collectively depict a
stream of deep moisture funneling into the southern CONUS on
Saturday and Sunday. Modeled streamlines indicate that this
moisture will be connected to both Pacific and Gulf sources, as
there is high confidence in deep mid/upper level troughing over the
Desert Southwest and a strong Caribbean ridge in this time frame.
The arctic surface high responsible for the cold surface
temperatures will propagate towards the Great Lakes this weekend.
This will flatten the isobars over the region and result in a broad
baroclinic zone stretching from the Southern Plains to the Tennessee
Valley. It remains uncertain how a shortwave trough diving into the
Northern Plains and the aforementioned southwestern trough will
interact/phase/evolve with one another as the weekend progresses,
but models generally depict a strengthening upper level jet over the
Ohio River Valley on Saturday night. It is also uncertain where a
surface cyclone may develop/track through the baroclinic zone in
response to these upper level features, but the ingredients for
dynamic lift appear to be coming into place over the forecast area
this weekend. Therefore, confidence in potentially significant snow
accumulations is increasing.

The latest probabilistic accumulation data from the 00z LREF Grand
Ensemble blend mirrors this notion. The probability of at least 1
inch (Winter Weather Advisory criteria) of snow accumulation now
stands at 85-95% across the forecast area through 12z Monday. If
this threshold is increased to 4 inches (Winter Storm Warning
criteria), those values remain at 60% along the I-64 corridor and
75% closer to the Virginia. If these storm totals are increased even
further to 8 inches, the probabilities range from 30-50%,
demonstrating the notion that significant snow accumulations cannot
be ruled out with this event. All of these values demonstrate the
continued upward trend with this event, and the spatial orientation
of these probabilities generally favor greater accumulations the
further south and east one goes in the forecast area. The potential
for a more significant snowfall is also captured by the latest ECMWF
Extreme Forecast Index/Shift of Tails (EFI/SOT) data, which resolves
an EFI of 0.6-0.8 and a SOT of 1-2 across the forecast area. These
values suggest that this event stands out in the climatological
model reanalysis data, but it should be noted that the Euro is
currently among the more aggressive pieces of guidance. Likewise,
the aforementioned snow probabilities assume a 10:1 ratio, and
specific snow ratios are difficult to pinpoint at this temporal
range. Deterministic accumulation output will remain bouncy for the
next couple of days, and it is simply too early to provide specific
accumulation numbers for specific locations. Nevertheless, most data
points towards a potentially impactful winter storm in Eastern
Kentucky this weekend. Interests are encouraged to review winter
storm preparedness information on weather.gov/safety/winter ahead of
time. Please stay tuned to forecast updates from trusted weather
sources in the coming days.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 745 AM EST TUE JAN 20 2026

VFR conditions will hold through the period with just passing mid
and high level clouds from time to time. Winds will oscillate
generally between a west and southwest direction with average
speeds of 3 to 7 kts through the period as surface high pressure
builds over the area.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
Cold Weather Advisory until 10 AM EST this morning for KYZ044-
050>052-060-104-106.

&&

$$

UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...MARCUS
AVIATION...CMC/GREIF