Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

367
FXUS63 KJKL 190637 AAC
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
237 AM EDT Sun Jul 19 2026

.KEY MESSAGES...

- A cold front approaches the area from the north early tomorrow
  morning, but stalls out across Southern Kentucky tomorrow. This
  allows additional storms to produce heavy rain in the
  Cumberland River Basin tomorrow.

- 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.

&&

.UPDATE...
Issued at 1218 AM EDT SUN JUL 19 2026

Although afternoon convection has been long died out, additional
activity ahead of the front is expanding from around the Ohio
River southward toward the JKL forecast area. Models have not
handled this well. The HRRR at least acknowledges it, but suggests
that it could largely slide by just to our northeast. Have updated
with a model blend, but there`s not a a lot of confidence in the
forecast.

&&

.SHORT TERM...(This evening through Sunday night)
Issued at 545 PM EDT Sat Jul 18 2026

Loosely organized bands of showers and storms continue to move
through the forecast area this afternoon, as the region is positioned
firmly within the warm sector of a deepening surface cyclone
centered up in the eastern Great Lakes. This feature is supported
aloft by a trough digging into the NE CONUS, with the trough axis
progged to dip down into the vicinity of the Appalachians and the
Mid-Atlantic overnight. Shortwave impulses moving around the base of
the broader troughing will allow additional showers/storms to
traverse through Eastern KY through this evening. The intensity of
this warm sector convection is shrouded in forecast uncertainty
though. Rain-cooler air has been noted in the immediate wake of each
round of convection today, and the area`s afternoon temperature
observations keep oscillating between the upper 70s and low/mid 80s.
This has caused forecast highs to under-perform previous
expectations in many locales, and convective cloud debris is
impeding upon peak diurnal heating. The more recent rounds of
convection have accordingly weakened upon approaching areas that
already saw rain, but outflow boundary collisions left over from the
earlier rounds have also been able to spark new storms. Where there
is still untapped instability, and if atmospheric recovery takes
root elsewhere, a few of this evening`s storms could produce gusty
to locally damaging straight line winds. Given modeled precipitable
water content values of 1.9-2.1 inches across the entire region, all
of this evening`s storms are poised to produce locally heavy
rainfall. Any attending flash flood risk appears conditional on
multiple rounds of stronger storms tracking over the same places
through the overnight hours. This is certainly possible, as the cold
front associated with the aforementioned low pressure system is
poised to approach from the north after sunset and bring additional
showers/storms to the CWA.

The Storm Prediction Center has maintained a Level 1/5 (Marginal)
Risk for Severe Weather for most of the CWA through 8 AM tomorrow
morning, with a Slight (2/5) Risk along/north of I-64. While this
risk does capture the more isolated minor wind damage potential from
the messier afternoon/evening activity, the latest hi-res forecast
guidance continues to collectively resolve a frontally-forced line
of convection dropping south of the Ohio River after midnight. These
showers and storms could take advantage of relatively greater wind
shear (15-20 knots, unidirectional) to become more organized, but
they will be working against the diurnal heating curve. That should
intrinsically limit the amount of available surface-based
instability for these pre-frontal storms, and a radiation inversion
may develop in sheltered SE locales after sunset. Breezy low level
winds out of the WSW will continue to advect warm, moist air into
the column ahead of storms` arrival, with northern and western
locations seeing the most effective advection. Therefore, the
greatest potential for stronger storms with tonight`s activity is
highest in our northernmost counties (hence the slight). The
activity is forecast to weaken and become outflow dominant as the
night progresses, but the outflow winds could still yield minor
impacts across southern counties. Furthermore, if there are any
standing outflow boundaries leftover from the ongoing round of
storms, an outflow collision could force an isolated storm or two
out ahead of the main line. Widespread, significant severe weather
is not expected in our CWA tonight, but there is enough of a gusty
wind and heavy rain signal to encourage interests to stay weather
aware through Sunday.

If there is an overlap between where radiational inversions are
realized after dark and where grounds are still wet from today`s
rainfall, fog could develop tonight. Otherwise, lingering convective
cloud debris and low stratus will insulate low temperatures into the
upper 60s/lower 70s. That cold front is not going to make it through
the entire forecast area tonight, and its upper level support is
progged to propagate off into New England tomorrow. This will leave
a stalling WNW->ENE oriented cold front draped across the forecast
area tomorrow as weak quasi-zonal flow aloft begins to veer
northwesterly. The airmass on the southern side of this boundary
will remain seasonably warm and anomalously moist, and as diurnal
warming processes take effect, the airmass should become
sufficiently unstable for additional showers and storms to develop
tomorrow afternoon/evening. This final round of activity will be
slow-moving and water-laden, so the torrential rainfall threat will
persist into tomorrow. The boundary parallel-flow yields an eyebrow-
raise pertaining to potentially-training convection in Southern
Kentucky tomorrow afternoon. Blended QPF guidance and this
afternoon`s CAM runs continue to paint a heavier 6-hour rainfall
bullseye in the vicinity of Lake Cumberland tomorrow afternoon, so
WPC carries today and tonight`s Marginal (Level 1/4) Excessive
Rainfall Outlook into tomorrow across our southern counties.
Depending on how tonight`s activity evolves, a locally higher flash
flood risk could emerge in our SW counties tomorrow. It is also
plausible for tonight`s storms to weaken/dissipate before reaching
tomorrow`s risk area. That would keep hydrological concerns more
isolated, so interests there are encouraged to monitor for near-term
forecast updates and weather alerts tomorrow.

On the other hand, northern portions of the CWA are poised to stay
dry tomorrow, with post-frontal NW flow advecting a relatively
cooler and drier airmass into the area. Post-frontal high pressure
builds into the entire area tomorrow night into Monday, which sets
up favored synoptics for ridge-valley temperature splits and
extensive overnight fog formation. Wet grounds could allow tomorrow
night`s fog to extend to more than just the river valleys, although
the greatest/densest fog is currently contained in the grids to
locations along the area`s waterways. That fog could impact the
Monday morning commute, marking a busy end to a very active short
term forecast period.

.LONG TERM...(Monday through Saturday)
Issued at 353 PM EDT SAT JUL 18 2026

As high pressure tries to build into the area Monday an upper level
low will dig into the Upper Midwest, Upper Great Lakes, and Ohio
Valley. Showers or storms are possible from Irvine to Jackson to
Pikeville and areas south, with chances increasing along the TN/KY
border, otherwise a mix of sun and clouds can be expected with dry
conditions and temperatures  in the mid to upper 80s. Monday evening,
temperatures are expected to cool into the upper 60s to near 70.

Tuesday, the upper level low will continue across the Great Lakes
as the systems cold front will extend southwest through the Ohio
Valley into the Central Plains. Afternoon temperatures are expected
to warm into the upper 80s to low 90s. Ahead of the cold front model
PWAT ranging from 1.8 to 2.0 inches along with dew points in the low
70s and temperatures in the upper 80s will all combine for hot and
muggy conditions. A 30-45 kt LLJ combined with 2500-3500 MUCAPE, 0-
3km SRH ranging between 150-200 m2/s2, and DCAPE 700-900 J/kg
suggests severe weather is possible Tuesday afternoon. As such the
SPC has put areas north of the Hal Rogers/ Kentucky Highway 80
corridor in a Day 5 Slight Risk for severe weather, highlighting at
least isolated to widely scattered damaging wind potential.
Temperatures are expected to cool into the upper 60s to low 70s.

Wednesday the cold front should be southwest of the forecast area,
however, isolated to scattered storms are possible across the Big
Sandy and including the southern parts of the Licking and Cumberland
River Basins. Otherwise, decreasing clouds through the day, with
temperatures cooler, in the upper 70s to low 80s, under  northwest
winds. Cooler air continues to work in, with lows in the upper 50s
to lower 60s Wednesday night.

While Thursday and Friday will remain dry under quasi-sonal flow,
the next shortwave looks to come out of the Northern Plains and
Upper Midwest introducing shower and storms chances again for  next
weekend. Temperatures Thursday will be cool in the upper 70s to
lower 80s, with temperatures cooling into the upper 50s to low 60s
at night. Temperatures Friday and Saturday average out in the mid
80s, with temperatures cooling into the mid 60s at night.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 235 AM EDT SUN JUL 19 2026

A few areas of convection lingered across parts of central and
eastern KY at issuance time with reduction mainly to MVFR.
However, a cold front slowly approaching from the north may bring
additional showers/thunderstorms during the first 6 hours of the
period. Forecast confidence is not very high on any of the TAF
sites being affected by SHRA or thunder so have generally covered
this potential with PROB30 groups. As the front nears, nearer to
12Z, MVFR to IFR reductions in low clouds are possible for a few
hours, before cloud bases lift with daytime heating. Around 16Z
and after, prevailing VFR returns for most locations. This should
be accompanied by a potential for renewed shower/thunderstorm
development from near KJKL to KSJS and points south. Reductions to
MVFR to IFR if not briefly lower are anticipated within this. By
00Z, the convection should wane, with some clearing late in the
period that could be conducive for fog formation in many locations
prior to 06Z.

&&

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

&&

$$

UPDATE...HAL
SHORT TERM...MARCUS
LONG TERM...GINNICK
AVIATION...JP