Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

496
FXUS63 KJKL 042329
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
729 PM EDT Mon May 4 2026

.KEY MESSAGES...

- Temperatures remain milder through Tuesday with potentially
  scattered showers and a few storms by evening.

- More widespread showers and a few storms are expected Tuesday
  night into Thursday morning, resulting in a beneficial rainfall.

- Below normal temperatures settle in through Saturday, with periodic
  low chances for showers heading into the weekend.

&&

.UPDATE...
Issued at 616 PM EDT MON MAY 4 2026

The forecast is on track, with just minor updates to T/Td and Sky
grids to account for current hourly trends.

&&

.SHORT TERM...(This evening through Tuesday night)
Issued at 410 PM EDT MON MAY 4 2026

As of mid afternoon, an upper level trough extended into the Central
conus from an upper low in Ontario. An initial shortwave/disturbance
was moving to the east and northeast of eastern KY while another
shortwave was upstream entering the Lower OH and TN Valleys. At the
surface, a ridge of high pressure extended from off the Southeast
coast to the eastern Gulf. Meanwhile, a frontal zone trailed into
the western Great Lakes into the mid MS Valley to Central Plains
into the western Conus.
Clouds have decreased since this morning as the disturbance and
associated convection has departed. Temperatures have moderated on
south to southwest flow and a few fair weather cumulus have
developed into the southwest portions of the area during the heating
of the day.

This evening and tonight, the next upstream disturbance should cross
the region this evening with no notable influence on sensible
weather. At the same time of mid afternoon, an upper level trough
extended into the Central conus from an upper low in Ontario. An
initial shortwave/disturbance was moving to the east and northeast
of eastern KY while another shortwave was upstream entering the
Lower OH and TN Valleys. At the surface, a ridge of high pressure
extended from off the Southeast coast to the eastern Gulf.
Meanwhile, a frontal zone trailed into the western Great Lakes
into the mid MS Valley to Central Plains into the western Conus.
Clouds have decreased since this morning as the disturbance and
associated convection has departed. Temperatures have moderated on
south to southwest flow and a few fair weather cumulus have
developed into the southwest portions of the area during the
heating of the day.

This evening and tonight, the next upstream disturbance should cross
the region this evening with no notable influence on sensible
weather. At the same time, the upper low in Ontario meanders toward
James By with the axis of the upper trough approaching the
Commonwealth. Yet another shortwave, potentially convectively
induced in the Plains and moving through this trough should reach
the mid MS Valley and near the OH Valley late. The pressure gradient
across the CWA will increase through the night so that leads to
uncertainty on the areal extent of deeper valleys decoupling with an
associated ridge/valley split and how much fog could develop in
those areas following recent rainfall. The headwaters region of the
Kentucky and the Big Sandy basin would be the most likely area for
some fog development or fog development that may tend to lift or
dissipate late tonight with the increasing gradient. For now as the
clear skies should favor some decoupling included some patchy fog
from around midnight through near sunrise on Tuesday given the
uncertainty. Assuming there is some decoupling a moderate magnitude
ridge/valley split may occur in the evening to the start of the
night with some valleys potentially rebounding to warmer
temperatures as the pressure gradient increases.

Tuesday and Tuesday night, the shortwave progged to near the Lower
OH Valley toward dawn should progress across the Lower OH Valley and
TN Valley on Tuesday while the upper low and another shortwave
progresses into Quebec and the St Lawrence Valley. The upper trough
axis should remain west of the OH Valley though. This will result in
the associated cold front only gradually sagging into eastern KY Wed
night. Following some mid level height rises late tonight into
Tuesday morning, deeper moisture advects into eastern KY ahead of
the shortwave trough and the approaching cold front. This scenario
should result in isolated to scattered showers and a few stray
storms late on Tuesday afternoon into early Tuesday evening. More
widespread activity should precede the front for Tuesday night.me,
the upper low in Ontario meanders toward James By with the axis
of the upper trough approaching the Commonwealth. Yet another
shortwave, potentially convectively induced in the Plains and
moving through this trough should reach the mid MS Valley and near
the OH Valley late. The pressure gradient across the CWA will
increase through the night so that leads to uncertainty on the
areal extent of deeper valleys decoupling with an associated
ridge/valley split and how much fog could develop in those areas
following recent rainfall. The headwaters region of the Kentucky
and the Big Sandy basin would be the most likely area for some fog
development or fog development that may tend to lift or dissipate
late tonight with the increasing gradient. For now as the clear
skies should favor some decoupling included some patchy fog from
around midnight through near sunrise on Tuesday given the
uncertainty. Assuming there is some decoupling a moderate
magnitude ridge/valley split may occur in the evening to the start
of the night with some valleys potentially rebounding to warmer
temperatures as the pressure gradient increases.

Tuesday and Tuesday night, the shortwave progged to near the Lower
OH Valley toward dawn should progress across the Lower OH Valley and
TN Valley on Tuesday while the upper low and another shortwave
progresses into Quebec and the St Lawrence Valley. The upper trough
axis should remain west of the OH Valley though. This will result in
the associated cold front only gradually sagging into eastern KY Wed
night. Following some mid level height rises late tonight into
Tuesday morning, deeper moisture advects into eastern KY ahead of
the shortwave trough and the approaching cold front. This scenario
should result in isolated to scattered showers and a few stray
storms late on Tuesday afternoon into early Tuesday evening. More
widespread activity should precede the front for Tuesday night.

.LONG TERM...(Wednesday through Monday)
Issued at 348 PM EDT MON MAY 4 2026

The long wave pattern will remain amplified through the period.
An upper level low will gyre around the vicinity of Hudson Bay,
allowing for broader cyclonic flow and general troughiness to rule
east of the Rockies through early next week. Model agreement is
good through the first half of the weekend, but then breaks down
for Sunday and Monday.

On Wednesday, a positively tilted trough will be aligned from
central Ontario through the eastern Pacific. At the surface, a
cold front will be stretched from New England through the Ohio
Valley and into the lower Mississippi Valley. This front will
bring some needed rainfall to eastern Kentucky, with widespread
showers and some thunderstorms expected during the day. The more
sustained shower activity will then gradually taper off from
northwest to southeast Wednesday night. On Thursday, another short
wave trough will bring some additional light rainfall to the
area, mainly favored over our southeastern terrain. High pressure
will then build in from the west on Thursday night. Overall, the
probabilities for event rainfall totals of greater than an inch
have remained in the 50-70 percent chance range, similar to 24
hours ago. The higher probabilties have also remained generally
over locations that have bigger rainfall deficits, near I-75 and
along and south of KY-80.

Dry weather will be short-lived across the Commonwealth on Friday,
as additional short wave activity rotates through the broad
cyclonic flow set up in the eastern CONUS. Another cold front will
approach and eventually move through the area Friday night and
Saturday, bringing in low rain chances. Dry weather returns for
Saturday night into Sunday morning, before the next system
encroaches by the afternoon, with rain chances continuing into the
start of the new week. Again, model agreement is poor by Sunday
and Monday, so confidence is low on the timing of the unsettled
weather at this time.

Temperatures will average below normal through Saturday. Highs
will be in the 60s to low 70s Wednesday, before retreating to the
50s and 60s for Thursday behind the departed cold front. Highs
will then moderate each day through Sunday, with highs in the
upper 70s to around 80 by that time. Depending upon the timing of
the next cold front, Monday highs would cool back to the upper 60s
and lower 70s. Lows will average in the 40s Thursday morning,
with some 30s possible for Friday morning, given the nearby high
pressure and clear skies overhead. Overnight temperatures will
then warm through 40s and 50s each day through early next week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 729 PM EDT MON MAY 4 2026

VFR conditions are expected through ~16z Tuesday with passing
mid- and high- level clouds, with increasing lower-VFR cloud cover
and potential shower activity after 18z Tuesday.

Although the winds at the surface are expected to slacken with the
loss of daytime mixing, a renewed low-level jet should be
marginally strong enough for mentionable LLWS between 02z and
~14z. At KSYM and KIOB, enough mixing is expected to keep
prevailing gusts of 15 to 20 kts through much if not all of the
overnight, so LLWS was not explicitly mentioned. Valley fog may
become an issue especially south and east of the TAF sites near
the deeper river valleys following recent rainfall, assuming these
locations decouple. Any valley fog at non TAF sites and the LLWS
threat diminishes between 12z and 14z with winds returning to
south to southwest at roughly 8 to 15 kts with gusts to around 18
to 23 kts through the daytime hours Tuesday.

&&

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

&&

$$

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