Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

302
FXUS63 KJKL 030900
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
500 AM EDT Fri Jul 3 2026

.KEY MESSAGES...

- Hot and humid weather persists at quite oppressive levels
  through the the start of the weekend.

- Chances for showers and storms return later today and build over
  the weekend.

- Thunderstorms from late today to the middle of next week may
  produce strong, to locally damaging, wind gusts along with
  heavy rainfall, potentially leading to a few instances of
  flooding.

&&

.SHORT TERM...(Today through Saturday)
Issued at 500 AM EDT FRI JUL 3 2026

08Z sfc analysis shows high pressure over eastern Kentucky while
ridging is also parked just about overhead. This is keeping skies
mostly clear and allowing for, higher dewpoint limited,
radiational cooling and the development of fog - mainly in the
river valleys. Temperatures and dewpoints are again similar this
night - both running in the muggy low to mid 70s most places, amid
light and variable winds.

The models, and their individual ensemble suites, are in great
agreement aloft through the short term portion of the forecast.
They all depict a fairly strong 5h ridge initially covering
eastern Kentucky but with time shifting southeast and weakening.
This will allow for some small height falls tonight and Saturday
along with more energy edging in from the west - south of some
faster west to east mid-level zonal flow north of the Ohio River.
Given the quite good agreement among the models, the NBM was used
as the starting point for the grids with some adjustment applied
for minor terrain details in the temperature grids tonight, along
with a lowering of the absolute peak of temperatures each day -
in favor of the multi-model mean.

Sensible weather features a mostly dry, hot, and rather sunny day
with only a small chance for late afternoon convection - probably
confined to the Cumberland Valley. This will mean another day of
oppressive extreme heat for the entire area. After a repeat of
the last few muggy and quiet nights with valley fog formation,
Saturday will see better chances of some relief from better
chances and more coverage of convection developing and moving
through the area. The CAMs suggest that the western parts of the
JKL CWA could see development as early as noon while the east
will take a bit longer allowing for both more time to heat up and
a greater threat for strong storms. The implications of this are
to lessen the heat extremes in the west but continue them in the
east - especially the valley cities and towns. The potential for
severe weather peaks in the east on Saturday afternoon as
indicated in the higher resolution convective allowing models
showing the the storms possibly forming organized clusters with
damaging wind gusts the main threat mode.

The main adjustments to the NBM starting point were to tweak the
NBM temps for minor terrain distinction tonight and not go quite
so high on maximum temps today and Saturday for most places. In
addition, have also applied a broad brush to the PoPs and thunder
chances on Saturday - smoothing out much of the specificity of
the finer resolution models.

.LONG TERM...(Saturday night through Thursday)
Issued at 200 AM EDT Fri Jul 3 2026

A pattern change is in store for Eastern Kentucky during the long
term forecast period. The antecedent ridging responsible for the
past week`s excessive heat is progged to break down by the end of
the holiday weekend. A well-defined shortwave trough digs into the
Upper Midwest in its wake, with the commonwealth positioned just
below the base of its axis. At the surface, this pattern shift is
marked by the departure of an anticyclone to the east and the
approach of a cold frontal boundary to the north. This allows a
plume of prefrontal moisture return to funnel into the forecast area
early next week, and the coverage of showers/storms accordingly
increases on Sunday and Monday. The related increase in sky cover
and localized pockets of rain-cooled air will provide some relief
from the heat, but it comes with a catch. Forecast guidance
generally resolves that frontal boundary coming to a crawl within
the forecast area, as its parent support aloft will propagate off to
the east and orphan it. On the warm/moist side of the resultant
quasi-stationary boundary, ample instability and atmospheric
moisture will favor additional convective development, especially
during peak diurnal heating and in Southern Kentucky. Given the
potential for multiple rounds of activity and the parallelism
between the quasi-zonal flow aloft and the increasingly west->east
oriented boundary, excessive rainfall concerns emerge early next
week. This is the aforementioned catch, but there is currently too
much forecast uncertainty to pinpoint specific details regarding
that risk.

When the period opens on Saturday evening, scattered, diurnally-
driven convection is likely to be ongoing across the CWA. The
previously-discussed instability should subside after sunset, with
modest ridge-valley temperature splits forecast. A few of the
conventionally cooler valleys could descend into the upper 60s on
Saturday night, with the rest of the area remaining in the low 70s.
These warmer-than-average MinTs reinforce the notion that an
exceptionally warm airmass will remain in place across the CWA ahead
of the early week boundary, although there should still be enough
radiational cooling for patchy river valley fog formation. Wet
grounds from earlier convection could cause locally dense pockets of
fog elsewhere, but confidence in this was not high enough to
explicitly include it in the grids.

Saturday night`s warmth will give Sunday`s temperatures a head
start, but greater precipitation coverage and the related increase
in sky cover will relegate Sunday afternoon highs to the upper
80s/lower 90s. Sunday`s PoPs are bolstered by the arrival of
relatively greater forcing, with dynamic, frontal, and convective
lifting mechanisms all in play. Forecast model soundings are not
particularly impressive from a severe convective standpoint, as the
1500-3000 J/kg of SBCAPE is met with less than 25 knots of effective
bulk shear for storms to get organized and sustain themselves. Thus,
minus the low-end chance for a cold pool-driven cluster/MCSes to
move in from upstream, Sunday`s convection looks pulsy yet again.
LREF mean PWAT values are in the 1.7-1.9 inch range, which ranks
around the 90th percentile of model climatology. We will need to
watch closely for water loaded downdrafts to produce gusty winds and
torrential downpours, and storms are not likely to be moving very
quickly. This setup persists into Monday in Southern and Eastern
portions of the CWA, and WPC has accordingly outlined our CWA in
Marginal (Level 1/4) Risks for Excessive Rainfall on both days.
While widespread flooding is not currently anticipated, we will need
to closely watch for any areas that experience multiple slow-moving
downpours multiple days in a row. Those locales will be the most
susceptible to flash flooding, and that risk will compound with each
day that this wet pattern remains in place.

It is currently unclear how long those rain chances will persist, as
model spread increases considerably early next week. The progressive
GFS continues to depict the the flow aloft backing towards a more
northwesterly orientation as the front pushes south and a
postfrontal high briefly builds into the area on Tuesday. The
European model family keeps the flow aloft parallel to the stalled
surface boundary while another shortwave trough organizes in the
Ozarks. While the former favors a return to drier weather and the
latter would allow the wet weather and hydro concerns to persist,
both favor temperatures relatively cooler than what we have
experienced in Eastern Kentucky as of late. The blended model
guidance used to populate the long term forecast grids smooths out
to 30-50% PoPs across most of the CWA through the end of the period.
The greatest chances will likely align with peak diurnal instability
each afternoon/evening, but future forecast packages will likely
contain changes to both the numeric values and the spatiotemporal
details of these rain chances. Regardless of the specific set-up,
either the advection of a cooler continental airmass into the area
or the presence of increased cloud cover and rain-cooled air will
bump high temperatures back down into the 80s next week. This is
much-welcome relief from the exceptionally hot conditions forecast
within the short term period, but interests in southern and
southeastern KY are encouraged to stay tuned to precipitation
forecast updates in the coming days.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 155 AM EDT FRI JUL 3 2026

High pressure will keep the weather benign for the majority of
the area with VFR conditions through the period. Fog through dawn
will be mostly confined to the valleys, but may impact a few of
the terminals from time to time between 06 and 13Z. Any remaining
fog should dissipate around 13Z, and we will be left with VFR
skies as diurnally driven cumulus develop between 4 and 5 kft agl
level through the afternoon. There is a small chance for a
thunderstorm late in the afternoon and this was included in the
more southwestern TAFs. Winds will remain generally light and
variable, away from any storm.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Warning until 8 PM EDT this evening for KYZ044-
050>052-058>060-068-069-079-080-083>085.

Heat Advisory from 8 PM this evening to 9 PM EDT Saturday for
KYZ044-050>052-058>060-068-069-079-080-083>085.

Extreme Heat Warning until 9 PM EDT Saturday for KYZ086>088-104-
106>120.

&&

$$

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