Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

319
FXUS63 KJKL 251946
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
346 PM EDT Thu Jun 25 2026

.KEY MESSAGES...

- Unsettled weather returns to end the week and into the weekend,
  with rounds of showers and storms possibly producing heavy rain
  and a flood threat.

- An extended period of hot temperatures begins Monday with high
  temperatures reaching into the low to mid 90s and heat indices
  nearing or exceeding 100 degrees.

&&

.UPDATE...
Issued at 649 AM EDT THU JUN 25 2026

Made minor updates to Sky and hourly T/Td grids, with little
change to the overall forecast.

&&

.SHORT TERM...(Today through Friday)
Issued at 253 AM EDT THU JUN 25 2026

A cold front currently located from the Upper Great Lakes to the
Central Plains will continue advancing southeast to the Ohio Valley
later today, nearly reaching the Ohio River before retreating back
north as a warm/stationary front Friday. Meanwhile, aloft an upper
level jet streak and disturbance will advance across the Lower Great
Lakes and northern Ohio River Valley Friday parallel to the surface
front, setting the stage for strengthening warm advection and
resulting in what is likely to be multiple rounds of showers and
thunderstorms moving east across the Ohio River Valley Friday into
Saturday.

As the front moves southeast towards the Ohio River Valley, showers
and thunderstorms should develop ahead of the front, but is unclear
if they will develop far enough south and east to reach our northern
counties. For now, we will continue to use the NBM 1-hour guidance
in keeping low-end PoPs roughly along and north of the Interstate 64
corridor from late this afternoon through tonight. Much higher
chances arrive by Friday afternoon and especially from early
evening onwards from west to east with the increase in warm
advection and a disturbance moving from the Mid-Mississippi
Valley east across the southern Ohio/TN Valley region, though many
models still keep the better instability and moisture west of the
escarpment until near or after 00z Saturday. This passing
disturbance will help allow higher dew points, and thus better
instability, to penetrate further through eastern and southeastern
Kentucky Friday night. Given this reasoning, the risk of
excessive rainfall will likely remain confined to the Bluegrass
region during the day Friday before advancing east with time into
Friday night.

.LONG TERM...(Saturday through Thursday)
Issued at 346 PM EDT THU JUN 25 2026

A significant pattern change to much hotter weather is still
anticipated as we close out the month of June and turn the
calendar to July. When the long-term period opens at 12Z Saturday,
the models are in good agreement showing shortwave troughing
aloft over the Ohio Valley to Eastern Great Lakes while a
developing ridge extends northward across the Plains from a broad
upper-level high extending from Bermuda to Northern Mexico. An ~550
dam closed low will also be diving into the Pacific Northwest
from the Gulf of Alaska. At the surface, a weak area of low
pressure will be situated near/over the Bay of Fundy with a cold
front extending southwest from the low to a weak area of low
pressure over southern Indiana and then west to a lee trough along
the eastern slopes of the Colorado Rockies. Convection is likely
to be ongoing across eastern Kentucky after daybreak Saturday
within the warm sector of the low, amidst a high PWAT air mass
(nearing 2.00 inches) and weak skinny instability (750-1250 J/kg
of MLCAPE).

While guidance varies on overall speed, the surface low will scoot
north of the JKL CWA during the day on Saturday with the trailing
cold front sagging to along or south of the Lower Ohio River, though
overall progress across the Commonwealth is uncertain due to
guidance spread. With morning convection and categorical PoPs,
sufficient destabilization for severe weather ahead of the cold
front remains an open question. Of greater confidence will be the
deep warm cloud layer, PWATs near or exceeding 2 inches and skinny
CAPE with high RH to the stratosphere, all of which will be
supportive of torrential downpours. Where rainfall is most
persistent, isolated instances of flash flooding remain a legitimate
concern and so most locations south of I-64 are in a Day 3 WPC
ERO Slight Risk.

By Sunday, troughing over the Western CONUS will continue to deepen
while the downstream ridging builds over the Central CONUS and a
closed high takes shape over the Lower Mississippi Valley. In
response, the frontal boundary will lift back to the north and
east with a generally lower probability of showers and thunderstorms
(mostly chance PoPs) on Sunday afternoon. The boundary continues
to progressively lift northeast through the new work week as the
center of the upper-level high drifts up into the Mid-
Mississippi and Lower Ohio Valleys. This will keep high humidity
in place from Monday through Thursday, but the rising heights
will tend to lead to some mid-level capping. LREF mean PWATs are
in the 1.5 to 1.6 inch range during this period. High humidity
values at the low-levels will support robust instability (2,500
to 3,500 J/kg of MUCAPE) formation each afternoon but it will
remain largely trapped by the capping inversion. However,
differential heating over the rugged Coalfield topography may be
sufficient to break the cap and yield isolated afternoon and
evening pulse thunderstorms. With weak flow and mid-level dry air
in place, it does appear that there is a risk for a few of the
most robust cores to produce strong to severe microburst winds as
they collapse. Temperatures will also be very hot with LREF mean
850 hPa temperatures reaching 20 to 21C on Monday, around 22C on
Tuesday, 22 to 23C on Wednesday, and around 23C on Thursday.
Probabilities for temperatures exceeding 90F across the lower
elevations are in the 50 to 70 percent range on Monday, 70 to 90
percent range on Tuesday, 80 to 100 percent on Wednesday, and 90
to 100 percent on Thursday. The high temperatures combined with
dew points in the low to mid 70s should support heat indices
nearing and in many locations exceeding 100F, especially by mid-
week.

In sensible weather terms, look for occasional rounds of showers and
thunderstorms, some of which could produce heavy rainfall and
instances of flooding on Saturday, becoming less numerous on Sunday.
It will be mild and muggy with highs in the low to mid 80s on
Saturday, warming into the 85 to 90F range for Sunday, while
nighttime lows range within several degrees of 70F. Thereafter, it
will be hot and steamy with temperatures soaring into the upper 80s
to lower 90s on Monday, and low to mid 90s each subsequent
afternoon. Nighttime lows stay mostly in the 70s. Heat indices
will reach new highs each afternoon with most places eclipsing the
100F mark by Thursday. Isolated showers and thunderstorms will be
possible each afternoon and may bring localized relief for some.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 201 PM EDT Thu Jun 25 2026

VFR conditions should prevail for the majority of the forecast
period. A diurnal cumulus field has developed this afternoon, and
a few passing cirrus clouds are noted in recent satellite
imagery. These clouds will not produce any ceiling impacts this
afternoon. Vsbys will also remain above impact thresholds at all
TAF sites. Valley fog formation is anticipated in SE KY again
tonight, but this will not affect the terminals. At northwestern
terminals, a stray shower cannot be entirely ruled out around 00z,
but these probabilities were not high enough to warrant an
explicit mention. Relatively greater rain chances enter the
forecast in the 04z-10z time frame at terminals along and north of
I-64, so Prob30 groups were introduced at KIOB and KSYM to
account for this. Mid to high level clouds will linger tomorrow
morning as another cu field develops. Tomorrow`s cu field should
eventually yield more impactful rain chances just beyond the end
of today`s 18z TAF period. In the mean time, expect SW winds to
give way to light and variable winds overnight and VFR conditions
to persist.

&&

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

&&

$$

UPDATE...CMC
SHORT TERM...CMC
LONG TERM...GEERTSON
AVIATION...MARCUS