Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

762
FXUS63 KJKL 302338
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
738 PM EDT Tue Jun 30 2026

.KEY MESSAGES...

- Hot and humid weather persists at quite oppressive levels
  through the rest of the week, likely peaking on Thursday.

- Mostly dry weather is anticipated through Thursday, before
  chances for showers and storms return to end the week.

&&

.SHORT TERM...(This evening through Wednesday night)
Issued at 402 PM EDT TUE JUN 30 2026

As of mid afternoon, an upper level ridge was centered over the
Commonwealth in the vicinity of the I-75 corridor and extended
across the Lower and middle OH Valley to the Great Lakes and into
the Southeast/Lower MS Valley. Further west, an upper level trough
was in place across much of the western Conus. At the surface, a
ridge of high pressure extended from the Lower OH Valley to the mid
Atlantic coast. Diurnally driven cumulus that developed in the late
morning/midday timeframe have been gradually mixing out. Many
locations were in the lower 90s at this point, with dewpoints in the
low to mid 70s. This yielded heat indices a few degrees either side
of 100.

This evening through Wednesday night, the 596 dm upper level ridge
will remain centered over or near eastern KY, though it will become
enlongated from east to west as a series of shortwaves move from the
Plains across sections of the Great Lakes and to the St Lawrence
Valley and Northeast Conus. At the same time, sfc high pressure will
remain centered in the Southern Appalachians.

The ridging will keep a very warm and humid airmass in place across
the region. Light winds and clear or most clear skies should result
in valley fog development tonight as well as Wednesday night. In
addition, the valley fog should lift into a diurnally driven cumulus
field on Wednesday. The ridging should keep this cumulus capped or
only limited in depth and shower activity is not anticipated. With
the dewpoints in the 70s, lows will be in the low to mid 70s and
offer only limited relief from the heat. Wednesday will be the
second of 4 consecutive days of heat indices expected to peak at or
near 105, an Extreme Heat Warning Remains in effect and will remain
in effect into the long term period on Friday.

.LONG TERM...(Thursday through Tuesday)
Issued at 354 PM EDT TUE JUN 30 2026

Unfortunately, little relief from the heat is expected at the
opening of the long term period. An upper level ridge will
continue to be centered over the Central Appalachians, keeping
weather hot and muggy across eastern Kentucky. Of note, Thursdays
record high in Jackson (a measly 93 degrees) could be in jeopardy.
NBM output suggests highs could generally range from the upper
90s to the low 100s across the forecast area; however,
temperatures this high are not currently supported by 850mb
temperatures in any model guidance. Given this trend, it is more
likely that high temperatures should generally range from the mid
to upper 90s across the forecast area, so MaxTs were nudged down
slightly to account for this. Additionally, with such a hot and
humid air mass in place, diurnally driven isolated convection
cannot be ruled out, particularly in the southern portion of the
forecast area. Associated cloud cover and precipitation could keep
temperatures cooler than forecast in affected areas, but the
majority of the forecast area should remain hot with limited
overnight relief as dewpoints remain in the 70s.

Friday will bring the first indications of a pattern change as
troughing generally becomes less amplified in the western CONUS
and embedded impulses are able to finally push the upper level
ridge axis to our east. With high pressure no longer directly
overhead, temperatures will be marginally cooler than Thursday
(largely in the mid 90s), although dewpoints will remain high.
This will allow for a slight increase in diurnal convective
coverage, with scattered storms possible on Friday afternoon and
evening. Given a moist environment (with LREF mean PW values
generally in the range of 1.6-1.7), any storm that develops could
be capable of producing brief torrential downpours. However, given
weak mid and upper level winds, shear will be so minimal that
truly organized convection is not expected.

Looking into the weekend and early next week, a transition to a
more active pattern and a gradual cooling trend is expected. Hot
and humid conditions will generally continue through this weekend,
with scattered storms possible each afternoon. On the Fourth of
July specifically, highs are currently forecast to remain in the
low 90s for much of the forecast area; however, with dewpoints
remaining in the 70s, it will still be noticeably muggy for any
outdoor activities, and scattered evening storms could become a
problem for Independence Day. With ample atmospheric moisture
(LREF mean PW values in the 1.6-1.8 range), torrential downpours
will again be possible with any convective activity. To account
for potentially high rain rates, the Weather Prediction Center has
introduced a Day 5 Marginal Risk (Level 1/4) for Excessive
Rainfall across eastern Kentucky, indicating the potential for
isolated flash flooding. Additional rounds of rain will be
possible through the end of the period as a frontal boundary
approaches at the surface and the upper level pattern evolves
towards increasing troughing and shortwave activity.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 738 PM EDT TUE JUN 30 2026

With high pressure remaining across the region, diurnally-driven
cumulus have largely dissipated but should return around 15Z.
Valley fog is expected to develop again tonight and affect the
typically favored valley locations between about 04Z and 13Z. At
this point, TAF sites are not expected to be affected. Winds will
remain light and variable through the period.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Warning until 8 PM EDT Friday for KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.

&&

$$

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