Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

435
FXUS63 KJKL 192307 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
707 PM EDT Tue May 19 2026

.KEY MESSAGES...

- Very warm and mainly dry weather will persist through this
  evening.

- Shower and thunderstorms will become more prevalent tonight and
  Wednesday, with rain chances continuing through the upcoming
  holiday weekend.

- The switch to an active and wetter pattern yields temperatures
  closer to normal readings, and is likely to provide at least
  temporary relief from developing and ongoing drought conditions.

&&

.UPDATE...
Issued at 707 PM EDT TUE MAY 19 2026

Given ongoing convection located primarily in Whitley and Laurel
counties, the main change to the forecast at this time was to
increase hourly PoPs for the southwestern portion of our forecast
area. Convective coverage is still expected to diminish around
sunset with the loss of daytime heating. Other than that,
temperatures and dewpoints were nudged and winds were adjusted to
be more in line with current observations.

&&

.SHORT TERM...(This evening through Wednesday night)
Issued at 400 PM EDT TUE MAY 19 2026

One more hot and mostly sunny afternoon is underway across eastern
Kentucky. Satellite imagery shows an extensive cumulus field across
the area and radar shows some spotty convection near and west of the
Pottsville Escarpment. Thermometers are also near record territory
for this date, ranging in the mid 80s for most. The latest
weather map shows the high pressure responsible for the hot and
dry weather of recent days now departing off the East Coast,
though still dominating over the southeast US. Meanwhile, an ~1004
mb surface low is situated northeast of Lake Superior while a
cold front extends southward from the low across the Ozarks and
Southern Plains. Aloft, an around 588 dam ridge remains over much
of the Southeast CONUS. Upstream, a 500 hPa trough is passing
through Central Canada and brushing the northern Plains while a
trailing shortwave is situated over the Great Basin. Vorticity
energy is streaming northeastward from the Western Gulf area and
across the mid-Mississippi and Lower Ohio Valleys in the
southwest flow between these troughs and the Southeastern ridge.

The northern stream trough will flatten and lift into eastern Canada
through the short-term period along with the remnant Great Basin
shortwave trailing as the ridging only slowly subsides over the
Southeast CONUS. Meanwhile, the surface low will lift northeast
toward Labrador while deepening ~990 mb. The low`s trailing cold
front will only slowly cross the Lower Ohio River late tonight
and sag across eastern Kentucky during the day on Wednesday.
Initially, upper level vort energy ejecting northeast from the
Western Gulf coast should aid in the development of diurnally-
driven scattered showers and thunderstorms through this evening,
primarily near and west of the Pottsville Escarpment though an
isolated shower or storm cannot be ruled out further east. Renewed
convective activity may impact locations near and north of I-64
Wednesday morning predawn as the boundary approaches our area.
Ahead of this boundary, the 19/12z HREF shows 1000 to 1500 J/kg of
SBCAPE building by afternoon with 20 to 30 kts of surface-500 hPa
shear south of I-64 by Wednesday midday to afternoon. This may be
sufficient for some cell organization, especially for convection
that develops discretely or in clusters out ahead of the cold
frontal boundary. SPC has included most of the area under a
Marginal Risk for severe weather on Wednesday for an isolated hail
or damaging wind threat. Cloud layer winds will tend to force
cells that develop along the actual cold front to move back atop a
more stable post-frontal environment, limiting overall extent and
vigor of convection along the true surface boundary. While PWATs
ahead of the boundary will rise to near or over 1.50 inches,
progressive cell movement and dry antecedent conditions (Moderate
to Extreme Drought) should preclude any notable hydro concerns
outside any urban/poor drainage areas that get a quick inch or two
of rain under the heaviest activity. For Wednesday night, shower
activity, mainly light, is likely to linger as disturbances aloft
continue to drift over the forecast area.

In sensible terms, spotty shower and thunderstorm activity will
continue through mid-evening, diminishing after sunset. Showers
may develop again toward morning, especially near and north of
I-64 and closer to central Kentucky. Temperatures will be mild
with lows in the lower to middle 60s. Additional shower and
thunderstorm activity is expected to spread in from the northwest
on Wednesday with highs ranging in the upper 70s northwest of
I-64 to the upper 80s in the deepest valleys near the KY-VA
border. Showers linger Wednesday night while temperatures settle
back into the lower 50s north of I-64 to the mid 60s near the KY-
TN border.

.LONG TERM...(Thursday through Tuesday)
Issued at 330 PM EDT TUE MAY 19 2026

The forecast period begins with the region situated on the backside
of a departing cold front. Although the boundary will be sagging
southward, scattered showers and thunderstorms remain possible
across the area. Given marginal instability and weak kinematic
profiles, severe weather is not anticipated, and activity should
remain largely garden-variety. Ongoing precipitation and cloud cover
will suppress daytime heating, keeping afternoon highs on the cooler
side. Temperatures are forecast to reach the lower 70s across the
northern portions of the area, while areas along the Tennessee
border should top out in the upper 70s. Overnight lows for Thursday
into Friday morning will remain mild as a quasi-stationary boundary
begins to lift northward as a warm front, initiating a warming trend.

This warm front will cross the region on Friday, serving as the
catalyst for widespread showers and thunderstorms throughout the
day. While marginal thermodynamic indices will once again favor
pulse-type, non-severe convection, the primary hazard shifts toward
heavy rainfall and high precipitation efficiency. This wet pattern
will persist through the weekend as precipitable water values climb
well above 1.50 inches within a deep moisture profile characterized
by a skinny CAPE distribution. Furthermore, ECMWF Shift of Tails
(SoT) values are progged to approach 0.8 on Friday before exceeding
0.8 Sunday into Monday. For context, a SoT greater than 0.8 is
highly indicative of an unusual event relative to the climatological
norm. As Fridays synoptic evolution locks the region into a pattern
supportive of repeated training rounds of convection, this event may
ultimately be classified as climatologically anomalous. An analysis
of the GEFS and ECMWF ensemble systems reveals strong model
consensus, with nearly all Total QPF members indicating that
rainfall totals upwards of 3.00 inches are possible through Monday
morning. The current deterministic forecast package projects
widespread QPF amounts ranging from 2.00 inches in the Lake
Cumberland area to 2.75 inches across northeastern portions of the
forecast area. Locations along the West Virginia and Virginia
borders will likely see lower totals due to local downsloping
effects. Once the stalled boundary finally shifts eastward on
Monday, another surface low is progged to develop and track
northeastward into the area. This system will bring a secondary
round of showers and storms, keeping the region wet through the
remainder of the forecast period. As a side note, since the area is
dry, heavy rainfall on top of moisture starved ground could create
runoff issues leading to potential hydrologic issues.

Ultimately, this period will highlight a distinct regime shift away
from the persistent dry pattern observed over the last few weeks
toward a much wetter synoptic setup. While the expected heavy
rainfall will help reduce the current precipitation deficit, overall
totals will still track below normal for this time of year. Due to
persistent cloud cover and rain, daytime highs will remain capped in
the upper 70s to lower 80s, while overnight lows drop into the lower
to middle 60s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 156 PM EDT TUE MAY 19 2026

VFR conditions will prevail through the daytime hours, but will
deteriorate gradually from the northwest through the period with
the approach of a cold front. Look for an extensive cumulus field
this afternoon with PROB30 groups to account for the low potential
of diurnally driven shower activity. Additional probabilities are
noted later tonight and on Wednesday as the cold front nears.

Winds will be the south to southwest at 6 to 13 kts again with
some gusts of 15 to 20 kts for this afternoon, highest at KSYM
and KIOB. These winds will diminish near sunset, but more exposed
sites will see a variable to southerly wind around 5 kts or so.

&&

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

&&

$$

UPDATE...FAGAN/JP
SHORT TERM...GEERTSON
LONG TERM...VORST
AVIATION...GEERTSON