Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

548
FXUS63 KJKL 201140 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
740 AM EDT Fri Mar 20 2026

.KEY MESSAGES...

- Temperatures steadily warm into the weekend, climbing into the
  70s today and Saturday then towards the 80s on Sunday.

- A passing disturbance will bring chances for showers and perhaps
  a thunderstorm to northern and eastern portions of the forecast
  area on this evening into the night.

- Expect gusty winds of 25 to 35 mph this afternoon ahead of that
  system.

- A better-defined, and stronger, cold front on Sunday night will
  bring more widespread shower and thunderstorm chances and a
  noticeable cooldown to the area. Strong storms cannot be ruled
  out.

&&

.UPDATE...
Issued at 725 AM EDT FRI MAR 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 zones.

&&

.SHORT TERM...(Today through Saturday)
Issued at 345 AM EDT FRI MAR 20 2026

07Z sfc analysis shows a weak area of low pressure off to the
northwest of Kentucky. This is supporting a warm front well north
of the area while its cold front is nearing western parts of the
state. High pressure to the south of the weather system has kept
skies mostly clear for eastern Kentucky for much of the night,
though some high clouds are settling in from the northwest. This
has led to a moderate ridge to valley temperature difference.
Specifically, readings vary from the mid 30s in the sheltered
valleys to lower 50s on the ridges. Meanwhile, amid mostly light
and variable winds, dewpoints are generally in the mid 30s.

The models, and their individual ensemble suites, are in fairly
good agreement aloft through the short term portion of the
forecast. They all depict a highly amplified 5h pattern consisting
of a large ridge over the Desert Southwest and troughing for the
eastern half of the nation. This has eastern Kentucky in broad
northwest mid level flow that will see a rather sharp but compact
and contained shortwave passing to the northeast by 06Z tonight.
In the wake of this, another batch of energy slips through by
Saturday evening from the west - favoring the Tennessee Valley as
it arrives. The longwave 5h pattern continues to de-amplify into
the weekend with significant weakening to the southwestern ridge
and troughing filling for the east. With quite similar model
solutions through the short term portion of the forecast, the NBM
was used as the starting point of the grids. The main adjustments
made to this initialization were to incorporate more in the way
PoP and thunder details from the latest CAMs to the fairly dry
PoPs from the NBM this evening and again Saturday afternoon.

Sensible weather features spring weather right on schedule with
warm conditions through the region into the weekend. The
approaching cold front to the northeast will support increasing
southwest winds - with gusts up to 35 mph - through eastern
Kentucky today - trying to moisten up the environment. This will
be key to provide enough instability to possibly develop a line of
scattered thunderstorms later this evening - mainly northeast of
KJKL. Models remain indecisive on the extents of any development
but the potential remain high enough to reasonably include in the
forecast - though the potential to be skunked remains. SPC
continues to highlight the area with Marginal Risk for severe
storms. Enough clouds and winds tonight will keep temperatures
mild and fairly uniform. Then Saturday our warmth continues while
a lingering sfc boundary may become active in the afternoon for
the southern parts of the CWA.

The changes to the NBM starting point primarily consisted of
beefing up the PoPs to chance in the northeast parts of the CWA
late this afternoon into the evening, as well as allowing a slight
chance for storms in the south on Saturday afternoon.

.LONG TERM...(Saturday night through Thursday)
Issued at 553 AM EDT Fri Mar 20 2026

The highlight of the long term forecast package continues to be the
passage of a cold front on Sunday night, as this will result in both
a nocturnal risk for strong to severe thunderstorms and a noticeable
cooldown. Compared to the Friday evening system discussed above in
the short term section, Sunday`s front will feature better-defined
troughing aloft, a stronger temperature gradient, and more favorable
convective parameter spacing. This leads to more widespread
prefrontal shower and thunderstorm coverage, but there are several
limiting factors to monitor with this particular set-up. Antecedent
conditions favor ridge-valley decoupling on Saturday night and
efficient diurnal mixing during the daylight hours on Sunday. While
the latter will allow forecast high temperatures to challenge record
readings on Sunday afternoon, both support the notion that the
boundary layer will be capped in the open warm sector on Sunday. The
currently available forecast model soundings depict a stout
nocturnal radiation inversion at the opening of the forecast period
on Saturday night and then a subsidence inversion atop the mixed
layer on Sunday afternoon. This will suppress the potential for
discrete convection, and thus the primary concern with this event is
for upstream convection to the NW of the forecast area to congeal
into a QLCS ahead of the better frontal forcing on Sunday night.

Thankfully, the arrival time of any linear convection here in
Eastern Kentucky will not align with peak diurnal heating. Storms
will have less surface-based instability to work with in our
forecast area, but 40-50 knots of 0-6km shear parallel to the
boundary and 500-1000 J/kg of CAPE will still pose a risk for
convectively-enhanced damaging wind gusts. Models also resolve an
intensifying southwesterly 850mb jet in this time frame, and this
could work to sustain a QLCS as it enters the forecast area after
dark. The chances for strong to severe storms are currently greatest
in areas to the NW of the KY-80 corridor, where SPC has outlined a
Marginal (Level 1/5) Day 3 Severe Weather Outlook. SPC highlighted a
Slight (Level 2/5) Risk in portions of KY closer to the Ohio River,
so we will need to closely monitor the evolution of any discrete
convection to the NW on Sunday evening. Confidence in specific
forecast details like timing and intensity will improve once this
event enters the temporal resolution of higher-resolution ensemble
guidance and the CAMs. For now, interests are encouraged to review
their nighttime severe weather safety plans and monitor for future
forecast updates.

Sunday night`s frontal boundary is also forecast to drop
temperatures by 20-30 degrees across the Commonwealth. Expect Sunday
to get off to a seasonably mild start, with ridgetop locales seeing
AM lows in the mid to upper 50s and the traditionally cooler valleys
in the 40s. There may actually be some patchy river valley fog to
start the day, but the efficient diurnal mixing and breezy
southwesterly winds (gusts up to 25 mph appear possible) should
allow temperatures to easily climb into the 80s area-wide on Sunday
afternoon. While LREF probabilities for maximum temperatures greater
than 85 degrees are not particularly high, the NBM ensemble
probabilities and the deterministic MOS guidance suggest that
Sunday`s highs may continue to trend upwards in subsequent forecast
packages. If even a one degree increase comes to fruition from the
current forecast, the record highs of 84 at the Jackson climate site
and 82 at the London climate site would both break. In the Big Sandy
Basin and in southeastern portions of the forecast area, proximity
to a surface high over the SE CONUS suggests that deeper mixing is
possible than what the baseline NBM guidance accounts for. Some MOS
guidance places highs there in the upper 80s, and climatological
knowledge suggests that dewpoints will likely be lower than the
default blended data. In locations where that deeper mixing is
realized, dewpoints will drop towards the 50 degree mark and set up
minimum RH readings in the 30s on Sunday afternoon. The resultant
30+ degree dewpoint depressions cement the idea that daytime
convection is unlikely on Sunday. Some modest dewpoint recovery is
still possible on Sunday evening as SW low level flow
persists/intensifies ahead of the front, but temperatures will have
already fallen into the lower 70s/upper 60s by then. That downward
slide will continue into the first few days of the upcoming work
week. Postfrontal northerly surface wind components and quasi-zonal
flow aloft will advect a cooler and drier continental airmass into
the forecast area for the beginning of the work week. The dryness of
that new airmass favors efficient clearing behind the front on
Monday morning, and NBM PoPs appear to be too high in this time
frame. However, the sunshine will likely not be enough to warm highs
out of the upper 50s/lower 60s on Monday afternoon. Expect lows to
plummet further into the 30s on Monday night/Tuesday morning as the
cool/dry air advection regime continues.

The parent troughing responsible for all of the above does not
appear particularly deep, and the forecast area will be positioned
just below the apex of the trough axis. As longwave ridging
amplifies over the SW CONUS through mid-week, additional shortwaves
are forecast to move around its northeastern periphery. These
features will oscillate the flow over the Ohio River Valley between
quasi-zonal and more northwesterly orientations, whereas the flow at
the surface should return to southerly directional components as the
postfrontal surface high propagates off to the east. There is a
notable increase in model spread regarding the timing and evolution
of those shortwave disturbances, which makes it difficult to
pinpoint specific forecast details right now. However, the
synoptic setup favors a return to near/just-above-normal
temperatures ahead of the next rainmaker towards the end of the
period.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 740 AM EDT FRI MAR 20 2026

VFR conditions will prevail through at least the first half of
the TAF forecast. A weak cold front approaches from the northeast
late this afternoon, and may also result in increasing cloud
coverage, but these should remain in the mid to high range through
00Z Saturday. Then, the front and any associated rain or storm
chances could briefly impact the KSYM or KSJS terminals (and
possibly KJKL) toward the 00-06Z time frame. Lower CIGs follow
into dawn, Saturday. There remains a large amount of uncertainty
with this system as far as coverage and extent, with many models
still painting a drier and more benign solution. As for winds:
look for them to be light and variable into mid morning before
picking up from the south to southwest at 10 to 15 kts with gusts
as high as 25 kts in the afternoon - diminishing to light after
sunset.

&&

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

&&

$$

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