Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

416
FXUS63 KJKL 180954
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
554 AM EDT Sat Jul 18 2026

.KEY MESSAGES...

- Warm and humid weather will persist this weekend, with all of
  the area expecting showers and thunderstorms at some point.

- Some thunderstorms could bring locally heavy rainfall and strong
  to damaging winds this afternoon into tonight. Additional
  storms with locally heavy rain are possible on Sunday.

- A more significant cold front should bring more showers and
  thunderstorms on Tuesday, with storms capable of heavy rain and
  strong to damaging wind gusts.

&&

.SHORT TERM...(Today through Sunday)
Issued at 540 AM EDT SAT JUL 18 2026

Early this morning, narrow upper level ridging extends from the
western Gulf into the Ozarks vicinity while an upper level trough
extends across eastern sections of Canada into the Great Lakes to
Northeast, mid Atlantic, and OH Valley. A weak disturbance
upstream of eastern KY was resulting ins some convection over
sections of central KY while a more substantial shortwave moving
through the trough extends from Ontario across the western Great
Lakes into the upper MS Valley vicinity. At the surface, an
associated sfc low was centered in the Lake Huron vicinity with a
cold front trailing into the Northern Plains/SD. Some valley fog
has developed overnight along with patches of stratus while
additional patches of low and mid clouds were also crossing the
area in addition to some passing cirrus. With the cloud cover
across the area, temperatures are mainly in the lower 70s.

Today and tonight, lingering valley fog and stratus should lift
and dissipate quite quickly this morning. Otherwise, the initial
weak shortwave/disturbance should progress across eastern KY this
morning while the more potent shortwave upstream rotates across
Great Lakes and sections of the OH Valley and into the Northeast
to Lower OH Valley vicinity. This will result in northwest flow
aloft later today and tonight. Meanwhile, the sfc low in Canada
should progress into the St Lawrence Valley and then to the
Maritimes. The trialing frontal zone should drop south of the
Great Lakes and sag to near or perhaps just south of the OH River
by late tonight. Ahead of this boundary, per the 00Z HREF mean,
PW should remain in the 1.7 to 2.0 inch range or roughly the 85th
to 95th percentile on average with low to mid 70s sfc dewpoints on
average. Daytime heating per the RAP should result in MLCAPE in
the 750 to 1750 J/kg range this afternoon to early evening, though
effective shear should be meager in the 10 to 20KT range. Low
level lapse rates should be steep with weak mid level lapse rates
and long skinny CAPE profiles. Thus, what slow moving convection
that develops today ahead of any potential line or lines of
convection along or ahead of the front appears to mainly pose a
threat for torrential downpours and perhaps some locally stronger
downdrafts/outflow gusts. This potential may be greater in the
north where shear though still quite weak will be a bit stronger.
Any lines or line segments could also pose a risk for isolated
strong to damaging wind gusts and torrential downpours leading to
a risk for isolated instances of flooding. Overall, guidance has
greater coverage of convection in the evening to overnight ahead
of the boundary.

On Sunday, a rather moist airmass with 70s sfc dewpoints and PW
on the order of 1.6 to 1.8 inches will remain ahead of the
boundary that slowly sags into eastern KY. Flow aloft and shear
will remain weak and storm motions will be rather slow and thus
locally heavy rain could remain a concerns for more southern
locations.

.LONG TERM...(Sunday night through Friday)
Issued at 445 AM EDT SAT JUL 18 2026

Sunday evening, some showers and storms may linger along and south
of the Hal Rogers/Kentucky Highway 80 corridor. This is subject to
models correctly resolving a cold frontal position across the
CWA. To the west, high pressure builds into the Upper Midwest and
Ohio Valley, while a secondary upper level low, originating out
of ALberta, is expected to progress across Southern Canada.

For sensible weather, expect showers and storms should be tapering
off heading into late Sunday evening. Clearing skies and light
winds will allow for patchy fog to develop and temperatures to
drop into the mid 60s. Following the anticipated rainfall over
the weekend, some of this fog could become dense in the valleys.

As high pressure briefly noses into portions of the OH Valley on
Monday, though a secondary upper level low/trough will gradually
move across sections of the the Upper Midwest, Great Lakes, and
Ohio Valley. A stray shower or storm is possible, particularly in
the south, during peak heating as the previously mentioned
boundary remains in the vicinity. Otherwise, on Monday, mostly
sunny skies and drier conditions are expected with highs in the
mid to upper 80s. Monday night, temperatures are expected to cool
into the upper 60s to near 70.

Tuesday and Tuesday night, the upper level low/trough will
continue across the Great Lakes as an associated cold front drops
across the Ohio Valley and parts of the Plains. Afternoon
temperatures are expected to warm into the mid 80s to around 90.
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 warm and muggy conditions. A
40 kt LLJ combined with 1500-2500 MUCAPE, 0-3km SRH ranging
between 150-250 m2/s2, and DCAPE near 1000 J/kg suggests severe
weather is possible Tuesday afternoon. A line segment or line
segments along or in advance of the cold front may evolve from
Tuesday into Tuesday evening and move into eastern KY. As such the
SPC has put the northern two thirds of the CWA (Hal Rogers
Pkwy/KY 80 and north) in a Day 4 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 finally be south to southwest of
the forecast area, however, a passing disturbance may result in
isolated to scattered storms across the Big Sandy and including
the southern parts of the Licking, Kentucky and Cumberland River
Basins. Otherwise, a trend of decreasing clouds is forecast
through the day, with temperatures cooler, mainly in the low to
mid 80s, under northwest winds. Cooler air continues to work in,
with lows in the lower 60s if not some upper 50s for Wednesday
night.

While Thursday and Friday currently appear dry, the next
shortwave looks to come out of the Northern Plains and Upper
Midwest potentially in time for next weekend. Temperatures
Thursday will be on the order of 5 to 10 degrees below normal, in
the upper 70s to lower 80s, with temperatures cooling into the
low 60s at night.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
ISSUED AT 227 AM EDT SAT JUL 18 2026

Although a stray shower or storm is possible during the first 6
hours of the period, the main aviation concern is fog formation
where low and mid level clouds scatter out. A few hours of
visibility reductions to MVFR or IFR is possible in many
locations including the TAF sites. Any fog should dissipate
shortly after sunrise, with additional thunderstorms possible at
times from midday through the end of the period. Any storms will
bring a period of MVFR to IFR reductions and the stronger storms
could bring wind gusts over 30KT. Otherwise, outside of any
storms, winds will be light and variable.

&&

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

&&

$$

SHORT TERM...JP
LONG TERM...GINNICK
AVIATION...JP