Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

282
FXUS63 KJKL 191940
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
340 PM EDT Sun Jul 19 2026

.KEY MESSAGES...

- A cold front sags into the Commonwealth today, and stalls out
  across southern Kentucky. This allows additional storms to
  potentially produce heavy rain in the Cumberland River Basin.

- A more significant cold front could produce multiple rounds of
  thunderstorms on Tuesday and Tuesday night. Those storms will be
  capable of producing damaging wind gusts and excessive rainfall.

&&

.SHORT TERM...(This evening through Monday night)
Issued at 340 PM EDT SUN JUL 19 2026

The latest surface analysis across the CONUS shows a 992 mb surface
low over the Canadian Maritimes, with a trailing cold front draped
across the Atlantic Seaboard. This cold front is presently moving
from north to south through the CWA. Along and ahead of the front,
showers and thunderstorms have developed and are slowly moving
south. To the north, surface high pressure is starting to build into
the northern portions of the area. Temperatures across the CWA range
from the mid 80s north of the Mountain Parkway to the lower 80s
south of the Mountain Parkway, where thicker cloud cover and
precipitation have occurred.

Through the remainder of the afternoon, the front will continue to
drop south through the region, with showers and thunderstorms
remaining present through sunset before dissipating due to waning
instability. The environment ahead of the front remains potent for
pulse thunderstorms, as upwards of 3000 to 3500 J/kg of SBCAPE
exists even with widespread cloud cover. Coupled with 700 to 1000
J/kg of DCAPE and PW values ranging from 1.5 to 2.0 inches, this
combination will favor thunderstorms capable of producing heavy
rainfall and gusty outflow winds. The primary limiting factor for
organized severe weather remains a lack of sufficient wind shear, as
effective bulk shear magnitudes are less than 20 knots. Nonetheless,
once sunset arrives, convective activity will dissipate. Clearing
skies overnight will then favor the development of locally dense
river valley fog and in locations that received rainfall Sunday
afternoon and evening.

Monday brings another day with shower and thunderstorm potential as
a potent upper-level trough begins to dive southeastward out of
southern Canada. The forecast surface low will move into the
northern Great Lakes, lifting a warm front northeastward through the
Ohio Valley. As this occurs, Sundays cold front will return
northward across the area as a warm front. This will initiate WAA,
triggering the development of showers and thunderstorms and allowing
temperatures to warm into the mid to upper 80s. Forecast soundings
ahead of and behind the lifting front show a gradual change in the
thermodynamic profile of Eastern Kentucky. Increasing CAPE and PW
values confirm a robust moisture-rich WAA regime entering the
region; however, wind shear continues to remain the missing
ingredient for organized severe storms. Like Sunday, showers and
thunderstorms will dissipate after sunset, giving way to clearing
skies and another night of potential for locally dense river valley
fog.

A cold front moving south through the area today is triggering pulse
thunderstorms capable of heavy rain and gusty winds, fueled by high
instability but limited by weak wind shear. Activity will diminish
after sunset, leading to clearing skies and patchy river valley fog
overnight. On Monday, the front lifts back north as a warm front
ahead of an incoming Canadian upper-level trough, bringing a return
of warmer temperatures, high moisture, and another round of
unorganized, afternoon thunderstorms that will fade by Monday
night.

.LONG TERM...(Tuesday through Sunday)
Issued at 340 PM EDT SUN JUL 19 2026

The extended forecast period will start out active as Mondays warm
front lifts north through the area, bringing an increase in shower
activity overnight Monday into Tuesday morning. Along with the
potential for early morning shower and thunderstorm activity, an MCS
is forecast to track southeastward toward the CWA from the southern
Great Lakes. The 18Z CAMs suite is starting to resolve this feature
at the far end of the forecast cycle. Model soundings ahead of the
approaching MCS depict a highly potent thermodynamic environment
capable of supporting strong to severe thunderstorms, with damaging
wind gusts serving as the primary threat.

The 12Z NAM forecast sounding reveals MLLCAPE values exceeding 2500
J/kg, effective bulk shear around 50 knots, and ESRH values near 175
m2/s2. Additionally, 0 to 3 km shear vectors of approximately 30
knots oriented orthogonal to the forecast UDCZ indicate that the MCS
will propagate into an environment highly favorable for maintaining
convective organization, where damaging wind signatures and brief
spin-up tornadoes are possible. However, uncertainty remains due to
meager low and mid-level lapse rates, which may act as a limiting
factor for deeper updraft acceleration. As well as, the potential
for ongoing shower and thunderstorm activity that could overwork the
atmosphere and atmospheric recovery doesnt occur. Nonetheless, the
area is under a SPC Day 3 Enhanced Risk for much of the area and
areas not in the Enhanced area are in the Slight Risk category.

In addition to the severe weather risk, an elevated hydrologic
threat is forecast to develop. The southern flank of the MCS is
expected to become the focus for training thunderstorms. Deep
moisture will be in place with forecast precipitable water (PW)
values exceeding 2.00 inches. This exceptional moisture profile will
support highly efficient rainfall rates over already saturated
soils, increasing the risk for flash flooding. Furthermore, ensemble
probabilities indicate that integrated water vapor transport will
approach the 99th percentile of climatology. In collaboration with
the Weather Prediction Center, the Day 3 Slight Risk Excess Rainfall
Outlook has been expanded to encompass the entirety of the JKL CWA.

As the forecast MCS and the actual cold frontal squall line exit the
area through the day Wednesday, surface high pressure will gradually
build into the region. This will usher in a period of dry weather
and slightly below seasonal temperatures through late Friday
afternoon. Extended guidance then suggests that the next low
pressure system will bring a return of shower and thunderstorm
chances beginning late Friday evening and persisting through the
remainder of the weekend.

The extended period opens with a high-impact weather setup as a
potent MCS and cold frontal squall line moves into an unstable,
highly sheared environment on Tuesday. This system brings a distinct
threat of damaging winds, brief tornadoes, and flash flooding. A
cold front cleans out the area Tuesday night, introducing a cooler
and drier high-pressure regime from Wednesday through Friday
afternoon before another storm system brings renewed rain chances
for the weekend.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 134 PM EDT SUN JUL 19 2026

A combination of MVFR and VFR observations exist across all TAF
sites with this issuance as a slow moving cold front is working
through the area. Showers and storms have developed and presently
staying clear of TAF sites; however, shower and storm potential
will persist through the sunset before dissipating. Clearing skies
will allow for fog development which could create MVFR to IFR fog
through sunrise. VFR conditions will build back into the area for
the rest of the TAF window.

&&

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

&&

$$

SHORT TERM...VORST
LONG TERM...VORST
AVIATION...VORST