Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

222
FXUS63 KJKL 171538
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1138 AM EDT Fri Jul 17 2026

.KEY MESSAGES...

- Hot and humid weather continues today, with widespread heat
  indices in the 90s to near 100 degrees.

- An anomalously moist airmass over the region should lead to
  rounds of storms through Sunday, some of which could produce
  strong wind gusts and heavy rainfall and localized flooding.

- Another cold front crosses the region Tuesday to Wednesday,
  bringing a strong to severe storm threat, followed by relatively
  cooler and drier weather to end next week.

&&

.UPDATE...
Issued at 1138 AM EDT FRI JUL 17 2026

Temps have warmed quickly this morning, and the building
instability is allowing cu and showers to begin developing, with
thunderstorms eventually expected. The clouds/showers will slow
the warm-up, but even so, it would seem that the warmest locations
will probably be a degree or two warmer than was forecast, and
minor adjustments have been made.

UPDATE Issued at 750 AM EDT FRI JUL 17 2026

Hourly grids were freshened up, mainly to go with less fog near
Lake Cumberland and west of I-75 initially this morning. Lingering
fog further east should lift and dissipate over the next hour or
so. Otherwise, stray convection that had been occurring around and
prior to sunrise has largely dissipated. For now, however, opted
to keep slight pops in the southwest for the next couple of hours,
before a general increase areawide with daytime heating.

&&

.SHORT TERM...(Today through Saturday)
Issued at 450 AM EDT FRI JUL 17 2026

Early this morning, the axis of an upper level ridge extended from
eastern KY to the Carolinas to near Bermuda. An upper level low
was over the Maritimes vicinity with a trough axis south to east
of the Northeast coast. The main westerlies remained near the
US/Canadian border from the Rockies eastward and a shortwave
trough moving within this west northwest flow was moving across
northern sections of Manitoba and Saskatchewan. Another upper
level ridge was centered in the WY vicinity with a weakness/upper
troughing from the Central Plains to TX. Well south of the OH
Valley, upper ridging was also centered near the mouth of the
MS/northern Gulf. In between that ridge center and the ridge axis
extending from eastern KY into the Atlantic, a weakness/weak upper
trough was also in place. At present, a gradient in PW/moisture
was over eastern Ky with PW near 1.15 inches in eastern Pike
County to around 1.8 inches near Lake Cumberland with PW near the
confluence of the OH and MS rivers 2 to 2.1 inches. Within this
moisture gradient stray showers had been present earlier in the
night near the Lake Cumberland region and at present a few
showers are present in western parts of the CWA from Powell and
Wolfe Counties south to Leslie and Bell counties and points west.
Outside of these showers and areas of low and mid clouds, valley
fog was present along the rivers, larger creeks, and lakes within
the Big Sandy, Kentucky, Liking, and Cumberland basin.
Temperatures remained mild, in the low to mid 70s.

Today and tonight, upper ridging will shift east and become
centered south of Bermuda while height falls are anticipated
across the OH Valley region as the shortwave currently in the
Manitoba and Saskatchewan vicinity moves into the Great Lakes.
This shortwave trough will move across Ontario and the central
Great Lakes to Quebec to the eastern Great Lakes to Lower OH
Valley through early Saturday evening. At the same time, a
corresponding sfc low should track from ND across the northern
Great Lakes to Quebec/St Lawrence valley through Saturday evening
with the trailing frontal zone gradually sagging across the
western and central Great Lakes. PW will climb today from the 50th
to 85th percentile range at present to the 85th percentile (1.65
inch) near the VA border to the 97th percentile (near 2 inches)
range per 00Z HREF by evening. PW should remain in the 90th to
97th percentile range (1.8 to 2 inch range) through early
Saturday, before decreasing to the 80th to 95th percentile (1.6
to 2 inches) range per 00Z HREF on Saturday evening.

For today, with the increasing moisture and temperatures expected
to peak near 90, MLCAPE per RAP should rise to the 750 to 1500
J/kg range in the east and the 1500 to 2500 J/kg range in the west
with weak shear. Mid level lapse rates will be weak, but low
level lapse rate should reach the 7 to 9C/km range. Isolated to
scattered storms should develop during the afternoon and evening.
Torrential downpours appear to the most probable hazard. The
increasing PW may result in some water loaded downdrafts capable
for strong to perhaps a couple of locally damaging wind gusts.
WPC has the region in a marginal risk for excessive rain. SPC has
also placed the region in a marginal risk for severe storms due
with wind the main threat. Convection should wane in coverage with
the loss of daytime heating on Friday night, though falling
heights will lead to the threat for isolated showers and storms at
night.

On Saturday, isolated to scattered storms should develop with the
heating of the day and continued gradual height falls. Late
afternoon/early evening MLCAPE per the 03Z RAP reaches the 1500 to
2500 J/kg range with effective shear still weak roughly 10KT near
the TN border and 20 to 25KT north of I-64. Steep low level lapse
rates, but meager mid level lapse rates are again anticipated. A
few strong storms with torrential downpours and strong to damaging
wind gusts will again be possible. The threat for a strong storm
with a wind and heavy rain threat may linger into the start of
the long term period. WPC has the more eastern portions of the
area that have the longer residence time of the higher total
moisture content in the column (PW) in a marginal risk for
excessive rainfall, with all of eastern KY also in a marginal
risk for severe storms.

All of these threats will be highlighted in the HWO and social
media posts, etc.

.LONG TERM...(Saturday night through Thursday)
Issued at 345 AM EDT FRI JUL 17 2026

Saturday evening into Saturday night, showers and thunderstorms
are anticipated across Eastern Kentucky, as a shortwave moves
through a positively tilted trough covering much of the Northeast
US and Southeast Canada and an associated cold front sags into the
OH Valley and portions of the Appalachians. Farther upstream, a
high amplitude ridge of high pressure will remain over the
Intermountain West, with the apex of the ridge axis extending well
into Alberta and Saskatchewan. Models also depict another upper
level low on the upstream side of the ridge, located in British
Columbia.

The cold front becomes draped across the Ohio Valley late Saturday
night and is expected to continue to sag south into Kentucky
on Sunday. PWATs will be close to 2 inches ahead of the cold
front, dropping to around 1 inch behind it. Storms ahead of the
cold front Saturday evening through Sunday will have potential to
put down localized heavy rainfall. The WPC has placed most of the
Big Sandy and southern portions of the Kentucky River Basins in a
marginal ERO Saturday through Sunday morning. While all of the
better severe weather parameters (especially shear) stay north of
the forecast area and in the Ohio Valley, there may be a low end
severe threat across Kentucky. Moderate instability is anticipated
and water loaded downdrafts could result in strong to damaging
wind gusts from isolated to scattered activity early Saturday
evening. Locations in and around thunderstorms may experience
gusty and erratic winds. Convective allowing models suggest a
weakening line of storms may move into eastern KY around sunset or
a bit after and there could be a small wind gust threat from this
as well. The SPC has the entire area under a marginal risk for
severe weather Saturday and more southern location on Sunday ahead
of the front where instability may be strongest.

Through Sunday, as the upper level low progresses deeper into
Northeast Canada, the trailing cold front slowly slides off to the
east producing additional showers and storms along the way. The
upper level low over British Columbia rides over the ridge of high
pressure over the Intermountain West. Height rises are expected
Sunday night through Monday, leading to a break in active weather
and mostly sunny skies Monday.

By Tuesday, the upper level low that was modeled to ride over the
ridge, spills down the lee side, into the Great Lakes and Ohio
Valley. Another cold front will pass trough the region Sometime
Tuesday afternoon into Wednesday morning. Some models are suggesting
a great deal of moisture accompanying this system and preceding the
frontal passage. There should be stronger flow aloft/more shear
with this system compared to this weekend, and strong to locally
damaging winds will be possible with any storms along or ahead of
the front. SPC has highlighted this potential mainly for northern
parts of eastern KY. However, details and timing of mesoscale
features will likely change over the coming days. This will continue
to be monitored. After showers and storms move through with the
cold frontal passage much drier air is forecasted to move into the
area. This will contribute to a dry Thursday.

Temperatures generally range from  the mid to upper 80s during the
afternoons and upper 60s to lower 70s at night, at least through
Tuesday. After the frontal passage Tuesday temperatures are expected
to cool some, ranging from the low to mid 80s during the afternoons,
cooling into the lower 60s at night.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 755 AM EDT FRI JUL 17 2026

VFR conditions prevailed at KSME, KJKL, KSJS, and KIOB with low
stratus at KLOZ and some MVFR reductions in fog at KSYM.
Reductions to MVFR, IFR, and in some cases lower than that were
occurring at non TAF site locations. This fog should lift and
dissipate through around 13Z. Otherwise, cumulus development is
anticipated by around 15Z to 16Z with isolated to scattered
showers and storms between 16Z and 00Z, with spatial coverage
likely the greatest for the more western terminals. PROB30s were
used to cover the potential for all but KSJS, where activity
should be more sparse. Outside of any showers and storms, expect
generally light winds.

&&

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

&&

$$

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