Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

805
FXUS63 KJKL 222317
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
717 PM EDT Wed Apr 22 2026

.KEY MESSAGES...

- A warming trend continues through Friday.

- More widespread shower and storm chances enter the forecast on
  Friday night into Saturday and then again early next week.

&&

.UPDATE...
Issued at 657 PM EDT WED APR 22 2026

Updated T/Td and Sky grids based on latest trends, with the
biggest impact upping the Sky grids in the north where there is
more cumulus development than initially anticipated at this hour.

&&

.SHORT TERM...(This evening through Thursday night)
Issued at 430 PM EDT WED APR 22 2026

Late this afternoon, an upper level trough extended from east of
Hudson Bay to the Maritimes and Northeast to the Atlantic while
an upper level ridge extends from Arkansas/Arklatex region to the
upper MS Valley to Manitoba. This leaves the Commonwealth and the
Appalachians in NW Flow aloft. A disturbance is currently moving
across the mid OH Valley region with dwindling showers in the Tug
Fork vicinity associated with it. At the surface, a quasi
stationary front extended from the mid Atlantic to just south of
the Great Lakes to low pressure in MT. A sfc ridge of high
pressure was in place from off the southeast coast into the
Southeast to Lower OH Valley region. The southwestern two thirds
of the area experienced deep mixing today and winds gusting to
around 20 to 25 mph. At the same time, dewpoints in these areas
dropped into the 30s resulting in min rh in the upper teens to 20s
percent range there with 30s rh in the narrow corridor from
Fleming to Martin to eastern Pike County where some rain fell.

Tonight, the axis of the upper level ridge will shift east into
the Lower OH Valley tonight with an other shortwave in northwest
flow passing northeast of eastern KY with 500 mb heights changing
little tonight. Meanwhile, sfc high pressure over the southeast
will settle over the Southern Appalachians. This will set the
stage for slackening winds by sunset and mostly clear to clear
skies. Following deep mixing today and the currently observed
mixed dewpoints, large diurnal ranges are expected to continue for
valley locations. Fro lows, low to mid 40s are anticipated for
lows in the deeper valleys or more than 10 degrees below NBM
deterministic values with mid 50s for the coalfield ridges.
Following rainfall from Fleming County southeast to Martin and
eastern Pike County and with late afternoon dewpoints higher in
those areas, some fog may form on the far northern and eastern
areas by not long after midnight.

Shortwave upper ridging shifts east with the axis over or near
eastern KY through Thursday and Thursday night. Further west,
upper troughing moves from the Rockies to the Plains and Central
Conus. The region will remain in the warm sector with a frontal
zone remaining from the mid Atlantic coast to the Great Lakes to
a sfc low pressure system moving from MT to Saskatchewan and
Manitoba. Further warming will occur on Thursday with southwest to
westerly flow, though dewpoints should mix back to the low to mid
40s, or possibly lower in some instances, with deep mixing once
again. Winds and gusts will be lighter, however. High pressure
remains dominant for Thursday night and another at least moderate
magnitude ridge/valley split is anticipated.

.LONG TERM...(Friday through Wednesday)
Issued at 532 PM EDT Wed Apr 22 2026

A more active weather pattern sets up over Eastern Kentucky for the
long term forecast period, with multiple meaningful chances for area-
wide rainfall through early next week. As a series of shortwave
disturbances erode away at the dominant SE CONUS ridging,
atmospheric flow will shift towards a more southwesterly orientation
and set up deeper, more efficient moisture return. Precipitation
chances peak as the surface frontal forcing associated with those
disturbances arrive, but more isolated to scattered warm sector
convection cannot be entirely ruled out either. Right now,
confidence in rainfall is highest in the Friday night-Saturday
afternoon and then the Monday afternoon-Tuesday morning time frames.
Widespread severe weather is not currently anticipated this far east
in the commonwealth, but the vigorous nature of the early-week
system bears watching. Expect increasing forecast confidence
regarding both the timing and intensity details as these events
eventually enter the temporal range of higher-resolution forecast
guidance.

The period opens on Friday morning with temperatures recovering from
overnight ridge-valley splits. Surface winds out of the southwest
and efficient diurnal mixing should allow temperatures to quickly
warm towards highs in the 80s. BUFKIT momentum transfer soundings
and recent CONS guidance suggest that wind gusts could exceed the
baseline NBM guidance, as does pattern recognition. So, wind gust
grids were blended towards the upper half of the teens, with breezy
readings up to 20-25mph possible. Most of the area will likely
remain dry during the afternoon hours, but those same soundings
resolve the convective temperature thresholds being met across the
CWA. This suggests that a few warm-sector pop-up showers/storms will
be possible on Friday afternoon, although they will likely struggle
to overcome a capping inversion.

More widespread rainfall is likely on Friday night into Saturday. As
an upper level shortwave enters the Ohio River Valley, a 25-35 knot
850mb jet out of the southwest spreads over the forecast stream and
saturates the column. Upstream convection will move into eastern
potions of the commonwealth overnight, but the misalignment with the
diurnal cycle and the lack of robust dynamics aloft suggest that
this activity is poised to weaken upon approach. The related
synoptic cold frontal passage has trended a little bit later, with
FROPA poised to occur from NW to SE on Saturday now. Some guidance
(like this morning`s NAM) suggests that a narrow corridor of
marginally favorable CAPE/shear ingredients could set up immediately
ahead of the boundary in the wake of weaker Saturday AM showers, but
there are many limiting factors that preclude confidence in severe
storms on Saturday. Expect cloudy skies to prevail after the sun
rises on Saturday. When coupled with the approaching frontal
boundary and its CAA, this will mute Saturday`s diurnal warming
curve. AM lows near 60 and afternoon highs in the mid 70s limit the
modeled instability profiles and thus any severe weather risk. As
such, this initial round of activity could prove more beneficial
than impactful. A widespread wetting rain is looking increasingly
likely, and the 12z LREF resolves 50-70% probabilities for at least
0.25 inches of rain between Friday and Saturday evenings in Eastern
Kentucky. Locally higher totals are possible where any thunderstorms
or multiple rounds of rain occur, and the QPF grids currently call
for between 0.4 and 0.6 inches of rain with this first round of
activity.

Guidance collectively resolves shortwave ridging briefly building
back into the forecast area in the wake of Saturday`s frontal
passage. If sufficient clearing is realized on Saturday night,
valley fog could develop, as all the aforementioned rainfall will
leave grounds wetter than they have been as of late. Sunday
generally looks like a warmer and drier day, with partly cloudy
skies and highs in the upper 70s/near 80. That ridging is generally
expected to move east by Monday, but the exact timing remains
uncertain. If it is a quicker propagation, return flow could lead to
warm-air advection type showers in southern portions of the forecast
area on Sunday evening. Confidence in this is low, but a quicker
return to SW flow could lead to a more robust environment ahead of
a second, stronger storm system early next week.

The upper- and mid-atmopsheric support associated with Monday and
Tuesday`s storm system looks more robust, with a sharper, negatively-
tilted trough ejecting into the Ohio River Valley in this time
frame. Surface cyclogenesis out ahead of this feature will pull a
warm front north on Monday morning, yielding vertically stacked
southerly to southwesterly flow in the atmosphere over Kentucky.
Open warm sector convection cannot be ruled out, but the best
frontal forcing will lag out to the west, closer to Paducah, during
the daytime hours. As the parent features propagate east later that
evening though, a more pronounced 45-60 knot 850mb jet will pump a
plume of instability into areas immediately ahead of any organized
prefrontal convection. However, this will not overlap with peak
diurnal heating, which will likely relegate the highest severe
potential to the west of the I-65 corridor. SPC has accordingly
adjusted their long-range severe weather outlook further to the west
than it was at this time yesterday, but the currently-available
probabilistic ML/AI guidance resolve lower-end severe probs in our
end of the state. As per usual, the severe risk in Eastern Kentucky
on Monday night will likely be contingent upon the evolution of
upstream activity. This system bears watching still, and interests
are encouraged to stay tuned to future forecast updates.

Confidence is a lot higher that the region will see an additional
round of highly-beneficial rainfall from this second system. The
highest rain chances (already in the 80-90% range) will come ahead
of the frontal passage on Monday night into Tuesday morning. The
LREF probabilities for the same >= 0.25 inch threshold are above 80%
across the entire forecast area between Monday and Tuesday
afternoons. If this threshold is increased to 0.75 inches, the
probabilities remain around the 40% threshold, and this particular
ensemble does not take into account convective-allowing models at
the current temporal range. Given that thunderstorms are likely to
produce locally higher totals with this second round of activity,
the QPF values in the grids are generally higher than they were in
the first. A widespread 0.75 to 1.25 inches of rain is currently
reflected in the grids between Monday morning and Tuesday evening,
and this should help mitigate ongoing drought and fire weather
concerns. Precipitation chances taper off behind the system`s well-
defined frontal passage on Tuesday and give way to cooler mid-week
temperatures to close out the month of April.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
ISSUED AT 717 PM EDT WED APR 22 2026

VFR conditions will prevail through the period under high
pressure, with passing high clouds from time to time.
Additionally, widely scattered high-based cumulus will likely
develop toward midday Thursday and continue through the afternoon.

Winds have started to slacken and will diminish to 5 kts or less
on ridges and more exposed locations by 02z to 03z, and likely
decouple completely in sheltered valley locations. West to
southwest winds will pick up a bit between 14z and 18z Thursday at
5 to 10 kts, with a few gusts to around 15 to 17 kt possible in
the afternoon.


&&

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

&&

$$

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