Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

577
FXUS63 KJKL 301135 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
735 AM EDT Tue Jun 30 2026

.KEY MESSAGES...

- Just a small chance for a stray shower or thunderstorm each day
  for most of the week. The vast majority of the area stays dry,
  though.


- Heat and humidity build today becoming quite oppressive by mid-
  week.

&&

.UPDATE...
Issued at 715 AM EDT TUE JUN 30 2026

No significant changes were made to the forecast with mainly just
the inclusion of the latest obs and trends for the T/Td/Sky grids.
Did issue an SPS for valley fog this morning, as well. These
minor adjustments have been sent to the NDFD and web servers along
with a freshening of the zones.

&&

.SHORT TERM...(Today through Wednesday)
Issued at 505 AM EDT TUE JUN 30 2026

08Z sfc analysis shows high pressure over eastern Kentucky while
ridging is building aloft just to the west. This is keeping skies
mostly clear allowing for, high dewpoint limited, radiational
cooling and the development of fog - mainly in the river valleys.
Temperatures and dewpoints are again similar this night - running
in the muggy low to mid 70s most places, amid light and variable
winds.

The models, and their individual ensemble suites, continue to be
in great agreement aloft through the short term portion of the
forecast. They all depict a fairly strong and expanding 5h ridge
covering Kentucky and basically parked overhead through Wednesday
evening and beyond. Broad subsidence from this will limit
vertical motion through the period while the sharp positive height
anomaly keeps any mid-level impulses well to the north and west
of the area. Given the quite good agreement among the models, the
NBM was used as the starting point for the grids with some
adjustment needed for minor terrain details for the temperature
grids tonight, along with a bit of extra drying each afternoon.
Did also lower the peak temperatures each day closer to a multi-
model mean.

Sensible weather features a dry and sunny day with only a stray
(sub 20%) afternoon shower possible near the highest terrain in
the southeast - leaving most places dry. Ample sunshine and a
dome of heat will make for a very humid and hot day for the entire
area. Little in the way of cooling each night will contribute to
the oppressive heat through the rest of the work week with no
substantive relief expected until perhaps some convective
activity ups the rain chances on Friday - Thursday`s chances are
very sparse. Given these stagnant and hot conditions into Friday
we have, in coordination with the neighbors, expanded the Extreme
Heat Warning east through the rest of the CWA and extended it
temporally through the day Friday. It should be noted that
confidence in a large portion of the CWA hitting criteria is lower
than than that of the other days considering the potential for
convection - organized or other. It is the length of time that we
are expecting such heat and limited relief at night that prompted
the expansion and extention of the warning this morning.
Wednesday is expected to be hotter and more oppressive than today
at this heat wave will be nearing its peak.

The main adjustments to the NBM starting point were to adjust the
NBM temps for terrain distinction tonight and go not quite so
high on maximum temps today and Wednesday. In addition, have also
tweaked dewpoints a bit lower than the still outlying NBM values
each afternoon.

.LONG TERM...(Wednesday night through Monday)
Issued at 330 AM EDT TUE JUN 30 2026

The long-term period opens Wednesday evening with an ~596 dam
high centered nearly directly over eastern Kentucky and a
corresponding surface high in place over the Southeastern CONUS. The
low-level air mass will be oppressively hot and humid with 850
hPa temperatures of 23 to 24C and dew points in the lower to mid 70s.
Upper-level troughing will be found upstream over the Western CONUS.

The hottest and muggiest air mass of the period will be over the
Coalfields and vicinity Wednesday night and Thursday as the upper
high lingers overhead. With strong solar heating and the air mass warming
even more, expect high temperatures to soar well into the mid 90s on
Thursday afternoon with some of the hottest spots flirting with
the upper 90s. These values combined with torrid dew points will
support heat indices in the 100 to 110F range. While forcing will be
weak, a few orographically induced showers or thunderstorms could pop
off. While shear will be weak, there will be plenty of instability,
so any pulse storm that does go up could be briefly strong.

The upper-level high will then slowly shift east and subside on
Friday and Saturday as western troughing deamplifies with a piece of
shortwave energy ejecting eastward out across the Plains toward the
Ohio Valley. As a result, there will be a gradual slackening in the
heat and an overall trend toward increasing PoPs each day as
disturbances pass aloft and a cold front eventually approaches from
the northwest. Most places dip back into the 80s for highs by next
Monday.

For Independence Day specifically, the daylight hours appear
mostly dry at this point with higher chances for hit-and-miss showers
and thunderstorms during the evening and early overnight. While not
as hot as Thursday, it will still be quite oppressive with highs
ranging from the lower to mid 90s while heat indices climb to between
95 and 105F.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 735 AM EDT TUE JUN 30 2026

As high pressure builds across the region, subsidence is
increasing and should suppress any convection through the aviation
period. Under mostly clear skies look for the valley fog to
dissipate over the next coupple of hours. Winds are also light at
the TAF issuance, and will remain that way through the remainder
of the forecast period - at less than 5 kts.

&&

.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.

&&

$$

UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...GEERTSON
AVIATION...GREIF