Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

108
FXUS63 KJKL 191827
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
227 PM EDT Thu Mar 19 2026

.KEY MESSAGES...

- Temperatures steadily warm through the end of the week, climbing
  into the 70s on Friday/Saturday and towards the 80s on Sunday.

- A passing disturbance will bring chances for showers and perhaps
  a thunderstorm to northern and eastern portions of the forecast
  area on Friday evening/night.

- Expect gusty winds up to 35mph on Friday afternoon ahead of that
  system.

- A better-defined cold front on Sunday night will bring more
  widespread shower and thunderstorm chances and a noticeable
  cooldown to the area.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 227 PM EDT THU MAR 19 2026

Early afternoon surface analysis reveals surface high pressure
centered over South Carolina, exerting a broad influence across much
of the eastern CONUS, including eastern Kentucky. To the west, a
surface low is tracking into northern Missouri, while to the north,
a 1011 mb surface low is dragging a cold front through the Great
Lakes. Despite these features, eastern Kentucky remains firmly under
the influence of the surface high, which is providing dry weather,
ample sunshine, and warming temperatures.

Surface high pressure will continue to dominate through the
remainder of the day, leading to dry conditions and temperatures in
the low to mid-60s. This pattern is being reinforced by upper-level
height rises occurring this afternoon and continuing through the
overnight hours. Tonight will feature clear skies and light winds, a
combination that will facilitate a ridge-valley temperature split;
sheltered valleys are expected to drop into the mid-30s, while
ridges are forecast to remain in the low to mid-40s. While eastern
Kentucky remains quiet tonight, a clipper system will dive out of
Manitoba and into the northern Great Lakes.

By Friday morning, this feature is progged to move into the Great
Lakes, placing the forecast area within the warm sector.
Temperatures are forecast to climb into the low to mid-70s,
accompanied by increasing surface winds as a LLJ moves into the
area. HREF probabilities for wind gusts greater than 30 mph are
between 50% to 60% across the heart of the CWA, but the forecast
utilizes an NBM mix weighted toward the 90th percentile for winds
through Friday afternoon. Along with the wind, chances for showers
and thunderstorms will increase as the associated cold front dives
southeast. Forecast soundings ahead of the front indicate limited
CAPE, but 45 to 50 knots of effective shear may compensate for the
lack of instability. Given these ingredients, the SPC has placed
most of the region in a Day 2 Marginal Risk, with all hazards
possible. However, the primary limiting factors are potential cloud
cover and a lack of deep moisture, both of which are reflected in
the lower instability values. Showers and storms will persist
through Friday night before tapering off toward the end of the
period.

The forecast period will be characterized by initial dry weather due
to high pressure, followed by increasing showers and storms Friday
night as a cold front tied to a Great Lakes clipper dives through
the region. Temperatures throughout the period will trend well above
seasonal averages.

.LONG TERM...(Friday night through Wednesday)
Issued at 604 AM EDT Thu Mar 19 2026

The long term forecast period is defined by a transitioning synoptic
weather pattern over the contiguous United States. The amplified
ridging over the Desert Southwest is expected to steadily flatten
throughout the upcoming weekend. As it does so, a series of
shortwave disturbances navigating around its northern/eastern
periphery will propagate into the Ohio and Tennessee River Valleys.
The approach of these disturbances will help push the antecedent
longwave Atlantic Coast troughing out to sea. At the surface, this
pattern initially translates to a blocking high over the Gulf Coast
states and a couple of low pressure systems moving through those two
valleys. The proximity of those lows introduce low-end rain chances
to the forecast in Eastern Kentucky on Friday night (<40% PoPs) and
Southern Kentucky on Saturday afternoon/evening (<20% PoPs), but
these initial systems look rather moisture starved. As their parent
shortwaves propagate east, so will that blocking high. This allows
for a brief period of more effective warm air advection and
marginally better low-level moisture return to persist into Sunday
evening. Then, a cold front moves through the region on Sunday night.
While its parent troughing aloft looks better-defined than the first
two systems, that troughing does not look particularly deep. 40-60%
PoPs and a noticeable cooldown are still in the forecast for Eastern
Kentucky on Sunday night/Monday morning, but the quasi-zonal nature
of the associated flow aloft will likely limit both the intensity of
this system`s convection and the longevity of its postfrontal cold
air advection. Expect sensible weather conditions to return to near
climatological averages in its wake across Eastern Kentucky early
next week.

When the period opens on Friday night, that first disturbance will
be impacting the forecast area. The best forcing for showers/storms
will be in the northeastern half of the forecast area, closer to the
system`s surface low moving through the Eastern Great Lakes. There,
chance PoPs (25-40%) are outlined. Elsewhere, the chance for
measurable rain looks low. The lack of deep moisture (mean PWAT
values are less than an inch) and declining diurnal heating after
sunset will limit the amount of surface based-instability for any
convection forced by that system`s frontal boundary. Still, the
couple hundred J/kg of mean MUCAPE and marginal bulk shear values
depicted in the currently-available forecast guidance could allow
for sub-severe thunderstorms to move across NE KY on Friday evening.

That first system`s frontal boundary is poised to push south into
the Tennessee Valley on Saturday, but with little to no effect on
the temperatures. Shortwave ridging will foster mostly clear skies
and highs in the mid 70s across our forecast area, but the approach
of a second, subtle shortwave impulse to our south could allow for
renewed rain chances in the Cumberland River basin later in the day.
PoPs have begun to show up there in a few more recent pieces of
forecast guidance, with the greatest chances aligning with peak
diurnal heating. Future runs of the NBM will likely trend towards
slight chance PoPs and perhaps a slight chance of thunder in
Southern Kentucky on Saturday afternoon/evening, but this isolated
activity is expected to be well below severe limits. Most of the
commonwealth should stay dry, and Saturday night looks like a good
night for ridge-valley temperature splits. Expect lows to remain in
the 50s on ridgetops, but to cool into the mid/upper 40s in the
typical valley locals.

Breezy southwesterly surface flow out ahead of Sunday evening`s
better-defined system should allow temperatures to quickly rise on
Sunday morning. Afternoon highs are forecast to peak in the low to
mid 80s across much of the forecast area. Diurnal mixing will lead
to 25-30 degree dewpoint depressions and 30-45% minimum RH readings
on Sunday afternoon, and the currently-available forecast model
soundings suggest that the atmosphere will be capped while the sun
is up. Therefore, mentionable precip chances are forecast to hold
off until after dark. The persistence of the southwesterly surface
winds into should allow for some marginal low-level moisture
recovery after sunset and before the better frontal forcing arrives.
LREF Grand Ensemble mean PWAT values rise to just above 1 inch
around midnight and immediately ahead of the cold front. Those
values are about a quarter of an inch higher than they were with
Friday night`s front, which supports the notion that the convective
ceiling is slightly higher with this third system. However, unlike
some of the more memorable events earlier this season, the
southwesterly winds are not replicated aloft, where the flow looks
quasi-zonal. Therefore, the lack of truly deep moisture and the
limited amount of related instability will act as major limiting
factors for any frontally-forced convection on Sunday night.

Despite this, strong to marginally severe storms cannot be entirely
ruled out with this third system. The misalignment with peak diurnal
warmth will likely mitigate the amount of available surface-based
CAPE, and there is a great deal of spread noted in the modeled
instability for Sunday evening/night. For example, there is well
over 500 J/kg spread between the 25th and 75th percentiles for
MUCAPE across the entire state of Kentucky at 8PM Sunday in the 00z
LREF Data. Mean values at that time stamp currently range from 500-
1000 J/kg, with approximately 40 knots of bulk shear. Any stronger
or more organized prefrontal convection could pose a marginal risk
for hail and/or damaging wind gusts, but the potential is limited by
the likely elevated nature of the activity. SPC has noted this
potential in their Day 4 forecast discussion, as do various
convective forecasting tools. The EFI/SOT for CAPE continued its
upward trend with tonight`s 00z run. There are now EFI values of 0.7
to 0.9 noted in the Bluegrass region alongside a small SOT contour
of 1. Likewise, the NCAR AI, CSU ML, and CIPS analog guidance tools
continue to draw 5-15% severe probability contours over much of the
region. A few of the NCAR AI models are notably more aggressive with
the probabilities for northern portions of the forecast area closer
to the Ohio River, but these look overdone compared to the rest of
the currently-available pieces of guidance. The overarching synoptic
set-up does not scream widespread severe weather, but a more
marginal event is plausible. As such, we will continue to closely
monitor Sunday`s convective potential in subsequent forecast
packages.

Deterministic models continue to trend towards a quicker frontal
passage on Monday morning, and the time-lagged NBM will likely trend
PoPs downward in future forecasts. Postfrontal northerly wind
components and surface high pressure will advect a cooler airmass
into the region for Monday and Tuesday, with highs near seasonal
averages and slightly below normal overnight lows. Yet another
passing shortwave disturbance to the north will bring an increase in
clouds and low-end rain chances by midweek, but also a shift in wind
direction. This allows for warming temperatures by the second half
of the work week, and CPC`s 8-14 day temperature outlook suggests
that the end of March will be marked by a return to above-normal
temperatures.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 125 PM EDT THU MAR 19 2026

VFR conditions will prevail through the TAF window. Light and
variable winds are expected through the period; however,
increasing southwesterly winds are forecast after 14Z/Friday.

&&

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

&&

$$

SHORT TERM...VORST
LONG TERM...MARCUS
AVIATION...VORST