Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

354
FXUS63 KJKL 041520
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1120 AM EDT Sat Jul 4 2026

.KEY MESSAGES...

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

- Scattered showers and storms are possible today and into
  tonight, before convective coverage increases during the latter
  part of the weekend.

- Storms through the middle of next week may produce strong to
  locally damaging wind gusts along with heavy rainfall and
  isolated instances of flooding.

&&

.UPDATE...
Issued at 1120 AM EDT SAT JUL 4 2026

Scattered showers and thunderstorms have largely faded late this
morning as the subtle forcing that initiated the convection
appears to be departing. In the wake of this activity, skies
should be come more sun-filled overall and that will help lift our
temperatures more rapidly into and through the 80s through early
afternoon. Still expect highs to eclipse the 90F mark at many
locations by late afternoon before any additional showers and
thunderstorms develop.

UPDATE Issued at 735 AM EDT SAT JUL 4 2026

Updated the forecast for the ongoing convection bubbling up in
the southwest parts of the area and also included the latest obs
and trends for the T/Td/Sky grids. These adjustments have been
sent to the NDFD and web servers along with a freshening of the
SAFs and zones.

&&

.SHORT TERM...(Today through Sunday)
Issued at 525 AM EDT SAT JUL 4 2026

08Z sfc analysis shows high pressure having slipped southwest a
bit and weakened over the past 24 hours. As such, it is now
located over Middle Tennessee but still providing light winds and
some subsidence for our area this night. Even so, strong to severe
convection was able to develop and sustain itself over a good
portion of the Cumberland Valley into the late evening hours.
After a few hour lull, the radar scope is showing renewed
development in the I-75 corridor while the earlier convective
debris clouds are fading out overhead. These clouds have likely
kept the worst of the nightly valley fog development at bay,
though some is showing up clearly in the far east. Meanwhile,
temperatures and dewpoints are again similar this night - both
running in the upper 60s in places that saw the rain to the low
and mid 70s elsewhere, amid light and variable winds.

The models, and their individual ensemble suites, are still in
great agreement aloft through the short term portion of the
forecast. They all depict the 5h ridge weakening and sinking south
as more mid level energy impulses are able to move into the area -
generally from the northwest through the rest of the weekend. This
trend culminates in troughing pushing into the Ohio Valley by 00Z
Monday bringing both height falls and additional energy to
Kentucky. Given the quite good agreement among the models, the
NBM was again used as the starting point for the grids with some
adjustment applied for minor terrain details in the temperature
grids tonight along with additional convective details provided by
the latest consensus CAMs guidance.

Sensible weather features an end to the worst of the heat for many
across eastern Kentucky today as convection will provide relief
where it occurs. Indications are that earlier showers and storms
(as well as the extra clouds associated with them) in the west
will interrupt the heating process and keep temperatures and heat
indices a bit lower for much of the day. Meanwhile, the east
appears that it may get through more of the heating process this
morning without such interruptions and allow for higher
temperatures and heat indices. This would all be fuel for stronger
storms later that afternoon and into the evening when there is a
potential for severe convective development with damaging wind
gusts as the main threat. These storms around the area should
provide enough cooling that will last into the night and help
break the heat wave while providing more low level moisture for
valley fog formation. Additional showers and thunderstorms -
strongest favoring the east - on Sunday should be the death knell
of the heat dome for our area as conditions return to ones more
typical of summertime and not on the hottest fringe of the
climatological norms.

The main adjustments to the NBM starting point were to again tweak
the NBM temps for very minor terrain distinctions tonight and to
add more high resolution CAMs details into the PoPs and thunder
potential grids through Sunday evening.

.LONG TERM...(Sunday night through Friday)
Issued at 430 AM EDT SAT JUL 4 2026

The main change to grids for the first part of the extended
forecast this morning was to add in minimal amounts of terrain
details each night on account of the still moist air mass and
only partly clear skies that will be in place through Tuesday
morning and beyond. Persistent troughing aloft still looks to
keep things fairly active and well hydrated through the end of the
work week keeping shower and storm chances in the sensible weather
forecast.

The previous long term discussion follows:

The long-term period opens Sunday morning with a pattern change
underway from a hot and mostly dry pattern this week to near
normal temperatures and unsettled weather for next week. The
03/12Z model suite analysis beginning at 12Z Sunday shows split
flow over the Great Lakes with troughing prevailing to the south
over the Ohio, Mississippi, and Tennessee Valleys while ridging
extends northward from the Great Lakes into northwest Greenland.
The remnants of the upper-level high that dominated this week
will have retreated to the far southeastern CONUS and out over the
Central Atlantic. Meanwhile, an ~593 dam high will reside over
the Upper Rio Grande Valley beneath a robust trough over Western
Canada. At the lower levels, the pattern is messy, though there is
likely to be some kind of a weak surface low near or over Indiana
with an associated subtle warm front extending eastward toward
the Mid-Atlantic and a decaying cold front extending back into
the Ozarks. A second weak low should be found near or over Lake
Michigan.

Heading into the upcoming week, guidance generally shows the
troughing aloft propagating eastward with time, with the southern
low fading and the more northerly low predominating and shifting
east toward the Mid-Atlantic by Tuesday and dragging a weak cold
front south of the Ohio River. As the trough and weak surface
reflection depart, that front stalls by Wednesday as heights aloft
rebound slowly. While spread increases, models suggest that the
western ridge will also break down fairly quickly by midweek as
another shallow shortwave trough (associated with the Western
Canada trough from the start of the period) drops southeast into
the Northeastern CONUS. PWATs will be seasonably moist (75th to
90th percentile relative to climo) to start the period, ranging
from 1.5 to 1.8 inches in the LREF mean on Sunday and Monday,
dropping off to around 1.5 on Tuesday as the cold front settles
through, and remains in the vicinity on Wednesday. Gradual
moisture recovery is then likely heading later in the week as the
next trough approaches. Given the synoptic features as well as
numerous weaker perturbations passing aloft, a generally unsettled
pattern is expected to persist throughout the week with diurnally
modulated convection (most widespread in the afternoon and early
evening, least widespread in the early morning) as the norm. The
driest day of the period appears likely to be Wednesday, but even
then isolated to scattered convection still appears probable.

In terms of heavy rainfall, a Marginal (level 1 of 4) ERO is in place
from Sunday through Monday night to highlight the threat of isolated
flash flooding should storms become persistent over a given location.
Temperatures through the period again start on the warm side Sunday
with highs close to 90F before settling back into the mid to upper
80s for daily highs each afternoon from Monday onward. Nighttime lows
retreat into the 65 to 70F range for most locales.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
ISSUED AT 750 AM EDT SAT JUL 4 2026

Aside from the storm near KLOZ, VFR conditions prevail at the TAF
sites for the 12Z issuance. The convective debris clouds around
and new clouds with the redevelopment kept river valley fog from
affecting all but far eastern parts of the area. Ongoing storms
have been addressed with tempo groups that also extended to nearby
TAF sites. We are also looking for the development of scattered
thunderstorms across the entire forecast area late this afternoon,
so these were handled with PROB30 groups at all of the aviation
terminals. Winds may become erratic and gusty in any thunderstorm
activity through the period, but otherwise, they will remain light
and variable. Given the low- confidence nature of this forecast,
aviation interests should monitor for potential TAF amendments
during the morning and early afternoon hours.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 9 PM EDT this evening for KYZ044-050>052-
058>060-068-069-079-080-083>085.

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

&&

$$

UPDATE...GEERTSON
SHORT TERM...GREIF
LONG TERM...GEERTSON/GREIF
AVIATION...GREIF