Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

244
FXUS63 KJKL 241430
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1030 AM EDT Tue Mar 24 2026

.KEY MESSAGES...

- A very dry air mass will settle over the region, dropping
  afternoon humidity levels into the 10 to 20 percent range today,
  and still sub-30 percent for most areas on Wednesday.

- Temperatures will soar to 15 to 20 degrees above normal on Thu.
  A strong cold front will then bring numerous to widespread
  showers and a chance of thunderstorms late Thu night into Fri.

- Much colder air returns behind the front this weekend, bringing
  the potential for widespread sub-freezing temperatures Fri and
  Sat nights.

&&

.UPDATE...
Issued at 1030 AM EDT TUE MAR 24 2026

There are no changes to the forecast with the late morning update.
Observed temperatures were updated and interpolated into the
hourly forecast grids.

UPDATE Issued at 716 AM EDT TUE MAR 24 2026

Temperatures have settled into the upper 20s in northern valleys
to the mid 30s near Lake Cumberland as day breaks across eastern
Kentucky. The high clouds crossing the area presently should thin
out by late morning. Still anticipate lots of sunshine this
afternoon with highs in the mid 50s north to mid 60s south with
very low humidity levels bottoming out in the 10 to 20 percent
range.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 254 AM EDT TUE MAR 24 2026

A much cooler air mass is enveloping eastern Kentucky this
morning on light northeasterly winds--temperatures range from the
lower 30s north of I-64 to the lower 40s over the Cumberland River
Basin, all under partly cloudy skies. At the surface, an ~1031 mb
surface high is passing across Lower Michigan and Lake Erie
between 500 hPa troughing over New England and 500 hPa ridging
over the Western CONUS. The Greater Ohio Valley region will remain
under a northwest flow aloft between these two upper-level
features through the short term period. Multiple perturbations
will bring increased upper-level moisture at times, but the low
levels will remain very dry as the surface high pressure drifts
southeast to over the Mid-Atlantic Coast. This will result in
surface winds veering northeast to southeast and downsloping off
of the Central and Southern Appalachians today into this evening
before turning more south to southwest on Wednesday along the back
side of the surface high, thus allowing for a gradual moisture
uptick within a mild southerly return flow.

For today, one of those upper perturbations will lead to some
increased high cloud cover this morning, but very dry air will be
present below 700 hPa. Once diurnal heating and mixing are underway,
the drier end of the NBM suite and HRRR are favored for dew
points. This yields widespread dew points in the mid-teens to
around 20F for this afternoon. Combined with temperatures in the
mid 50s north of I-64 to the mid 60s near the TN/KY border, this
should yield minimum relative humidity values in the 10 to 20
percent range at most locations. This will help dry out the finer
fuels, but weak winds should limit overall fire danger.

Tonight, another upper-level perturbation will lead to increased
cloud cover, but it should remain thin enough for at least a moderate
ridge-valley temperature split. The dry dew points will allow
rapid temperature falls in valleys after sunset, yet weak low-
level WAA on the back side of the high should keep thermal belts
mild. The result is forecast lows ranging from the upper 20s in
the sheltered northern hollows to the mid 40s on thermal belt
ridges. (Note that some of the COOP MOS suggests mid 20s in the
coldest valley locales but cloud cover thickness will be a
factor). Some patchy frost is possible in sheltered valleys.

Air temperatures and dew points will be on the rise for Wednesday
under mostly sunny skies. Look for afternoon highs in the upper 60s
to lower 70s while dew points recover into the 20s east to 30s
west, yielding minimum relative humidity values in the 15 to 30
percent range. Winds will also be stronger on Wednesday from the
south southwest at 5 to 10 mph with some gusts to around 15 mph
possible at times.

.LONG TERM...(Wednesday night through Monday)
Issued at 512 AM EDT Tue Mar 24 2026

Eastern Kentucky opens the long term forecast period by being
positioned within a warm air advection regime. Southerly to
southwesterly low-level flow is expected to intensify from Wednesday
night into Thursday, pumping a relatively warmer/moister airmass
into the column. Expect seasonably warm overnight low temperatures
in the 50s west of I-75, in the Bluegrass, and atop ridges.
Depending on the amount of overnight cloud cover that is realized,
the sheltered and shaded valley locales further to the east could
thermally decouple. Even if this occurs though, the WAA processes
will be enough to keep Thursday AM lows well above freezing. The
aforementioned southwesterly winds correspond with both the shift of
the antecedent surface high to the east and the lifting of a warm
front through the region on Thursday morning. Isentropic lift on the
northern nose of the related moisture return leads to low-end (15-
25%) shower/storm chances during the AM hours on Thursday, but model
soundings suggest that any convective activity will be both elevated
and weak in that time frame. The boundary looks to move north
towards the Ohio River by midday, placing Eastern Kentucky in the
open warm sector ahead of a stronger cold front`s approach on Friday
morning. The resultant tightening of the surface pressure gradient
ahead of FROPA suggests that SW winds could gust up to 25-30 mph on
Thursday afternoon. These gusts will be aided by diurnal mixing,
which, in turn, allows highs to warm into the upper 70s/near 80s.

Traditionally, similar instances of springtime warmth out ahead of a
cold front signal potential for stronger pre-frontal thunderstorms
in the Ohio River Valley. While this particular system is forecast
to yield widespread rain chances across Eastern Kentucky on Friday,
the timing of its FROPA misaligns with peak diurnal heating and
instability. By the time the best frontal forcing arrives on our
side of the Ohio River, temperatures will have already radiationally
cooled into the 60s. Thanks to persistent southwesterly surface
winds overnight, dewpoint temperatures are forecast to remain in the
the mid/upper 50s ahead of the front. This corresponds with mean
PWAT values around 1.25 inches ahead of the front, but forecast
model soundings depict a stout capping inversion across the I-64
corridor as precipitation chances rise to >50% on Friday morning.
The parent synoptics aloft with this system do not appear
particularly sharp, with uniform, quasi-zonal flow noted above the
850mb level across most deterministic forecast guidance. This will
introduce some relatively drier continental air into the midlevels
over our forecast area, and thus cap the intensity of any frontally-
forced convection. Slightly better convective parameter spacing is
noted to the NW of the forecast area on Thursday night, and SPC has
accordingly drawn a Day 3 Marginal (1/5) Risk for portions of the
commonwealth to the NW of I-64. Locally though, the current
expectation is for linear upstream convection to weaken into general
rain showers as it sags south across the forecast area on Friday
morning.

Friday`s sensible weather forecast will be highly dependent on the
timing of this cold frontal passage. Given that the most probable
solution is currently an AM frontal passage from north to south, the
traditional diurnal heating curve is expected to be muted by
plentiful cloud cover, rain-cooled air, and a shift to northerly
surface flow. Friday`s MaxTs could occur before noon, and in many
places, temperatures will steadily drop throughout the day. The
above conditions also will keep any pre-frontal diurnal instability
in Southern KY at bay on Friday afternoon. All this to say,
anafrontal rain showers appear to be most likely forecast solution
with this particular atmospheric set up.

Perhaps the most significant sensible weather impacts with Friday`s
frontal boundary will come from the drop in temperatures and
dewpoints behind it. Post-frontal northerly winds will advect a much
drier and colder airmass into Eastern Kentucky on Friday night, with
widespread lows near or below freezing. The 00z LREF Grand Ensemble
currently resolves a >50% chance of freezing MinTs across the entire
JKL CWA on Saturday morning, with >80% chances noted north of I-64.
Interests with sensitive plants should monitor future forecast
updates closely, as a frost is possible on both Saturday and Sunday
mornings. Sunday morning could actually be even colder than Saturday
morning if ridge-valley temperature splits come to fruition and
valley locales drop into the low/mid 20s. Saturday`s persistent dry
air advection and the proximity of a broad, post-frontal high
pressure system overhead reinforce the idea that these splits are
plausible. Such synoptics favor efficient diurnal mixing, and
afternoon MinRH values could drop below the critical 25% threshold
on Saturday afternoon. Mixed boundary layer dewpoint data from the
GFS and BUFKIT momentum transfer soundings suggest that mesoscale
processes could lead to single digit dewpoints and 40-50 degree
dewpoint depressions in Eastern Kentucky on Saturday afternoon.
Thankfully, winds will be fairly light within this continental high
pressure regime, but elevated fire weather danger appears plausible
on Saturday afternoon thanks to the utter dryness of the resultant
airmass. It should be noted that these mesoscale forecast details
are not currently reflected in the baseline NBM data used to
populate the long term forecast grids. As the time frame approaches
and forecast confidence increases, edits will be made accordingly.
For now, fire weather interests should take note of the forecast for
very dry weather on Saturday, and the general public is highly
encouraged to follow all subsequent burn guidance or bans from the
appropriate local, state, and federal authorities.

Cool, dry sensible weather continues into Sunday, but the previously-
discussed synoptics are forecast to shift east headed into the next
work week. This favors progressively veering return flow, steadily
warming highs, and gradually increasing amounts of atmospheric
moisture on Sunday, Monday, and Tuesday. Another rain-producing
system is poised to approach the area at the very end of the
forecast period, but it is too early to provide specific details
regarding its timing and any potential impacts right now.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 730 AM EDT TUE MAR 24 2026

VFR conditions will continue at the TAF sites through the forecast
period as high pressure passes over the Upper Ohio Valley today and
settles off the Mid-Atlantic coast by 12Z Wednesday. Only some
high and mid level clouds are anticipated from time to time across
eastern Kentucky. In this pattern, northeast to easterly winds at
less than 10 kts are expected through the TAF period.

&&

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

&&

$$

UPDATE...CMC
SHORT TERM...GEERTSON
LONG TERM...MARCUS
AVIATION...GEERTSON/JP/GUEST