Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

251
FXUS63 KJKL 012311
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
711 PM EDT Wed Jul 1 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 and over
  the weekend.

&&

.UPDATE...
Issued at 626 PM EDT WED JUL 1 2026

The early evening update is out with no changes needed outside of
updating near-term hourly T/Tds with the latest measured observations.

&&

.SHORT TERM...(This evening through Thursday night)
Issued at 400 PM EDT WED JUL 1 2026

This afternoon, an upper level ridge was centered near the WV and
KY border with this ridge extending across much of the eastern
Conus while a trough extended across portions of the western
Conus. At the surface, a ridge of high pressure was centered
across the central to southern Appalachians. Near to the center of
the ridge cumulus that had developed late in the morning to
midday had largely dissipated east of I-75 and outside of the
highest terrain of Harlan County and Wise County VA. Temperatures
were mainly in the 90s below 2000 feet with dewpoints mainly in
the 70s. This was yielding heat indices in the mid 90s to 105
range.

This evening through Thursday, the upper level ridge is expected
to remain centered in the vicinity of WV, but may become more
flattened or oriented more east to west with time downstream of
the troughing in the western Conus. The ridging should keep
cumulus largely capped through Thursday, though the capping may
begin to become a bit weaker further from the center of the ridge,
generally in sections of the Southern Appalachians to TN Valley
and south of the Commonwealth. This will support another night
with valley fog formation around or shortly after midnight that
dissipates within a couple hours after sunrise. Forecast soundings
from the 12Z HREF suggest that at least some cumulus should again
form by late morning to midday though may again tend to mix out
through the afternoon. 850 mb temperatures are progged to warm
slightly for Thursday, and Thursday may be the height of the heat
wave. The center of the ridge slides further east of eastern KY on
Thursday night as the first in a series of shortwaves troughs
moves into the Central conus and nears the MS Valley.

12Z and 18Z HRRR runs kept convection south of the KY/TN border in
sections of the Southern Appalachians to TN Valley as did the 00Z
and 12Z ECMWF as well as the 06Z and 12Z NAM. The 12Z ARW and FV3 do
have some convection in the late afternoon/evening as far north as
eastern KY with the FV3 as is typical among the most aggressive.
The 12Z GFS may be affected by some convective feedback issues or
appears to be over-convecting in the least in the Southern
Appalachians that then moves west and northwest around the ridge
and into eastern KY on Thu night. Confidence in these more
aggressive solutions and a slightly weaker ridge allowing
convection that far north is low. However, did opt to have slight
chances pops in the late afternoon/early evening along the TN
border from Bell to Wayne Counties and not nearly as far north as
the general thunder and marginal outlooks in the SWODY2, capping
pops later in the evening/overnight to 14 percent.

.LONG TERM...(Friday through Wednesday)
Issued at 359 PM EDT WED JUL 1 2026

At the onset of the long term period, eastern Kentucky will find
itself on the western side of the aforementioned upper level high
as the ridge finally begins to translate east and break down. High
temperatures on Friday will remain well above average (generally
in the upper 90s across the forecast area). However, given the
eastward translation of the ridge, in addition to ample
instability and an uncapped environment, convective coverage will
likely be higher than in previous days, and any diurnally driven
thunderstorm activity could reduce high temperatures. Further
complicating matters, some models depict small scale impulses
rotating along the periphery of the upper level ridge, which could
provide an additional forcing mechanism for convective activity,
especially for our western counties. In fact, a few models show a
signal for MCS activity in the Ohio Valley late Friday, although
confidence is low in this solution at this time. Given such a
muggy and hot environment, instability will likely be anomalously
high, with LREF mean SBCAPE exceeding 3000 J/kg in the western
portion of the forecast area, although shear will be extremely low
given exceedingly weak flow aloft. Accordingly, the Storm
Prediction Center has introduced a Marginal (Level 1/5) Risk for
severe thunderstorms across our entire forecast area, and machine
learning guidance is in good agreement with this. Damaging winds
associated with pulse convection would generally be the favored
hazard in this environment; however, should an MCS solution come
to fruition, the wind threat could be more widespread, and this
potential will need to be watched as more CAMs become available.
Regardless, convective activity is expected to decline overnight,
with typical valley fog developing in mainstem river valleys.

The upper level ridge will continue to break down over our area
this weekend, with marginally cooler high temperatures expected
each day as upper level troughing gradually digs closer to our
forecast area. To our north, a west to east oriented frontal
boundary will sit over the Great Lakes region; however, with
little to push this boundary south, it should remain relatively
stationary through the weekend. In the absence of any larger scale
forcing mechanisms, additional rounds of diurnally driven
convective activity will be possible Saturday and Sunday
afternoon, with increasing column moisture each day. The Weather
Prediction Center has introduced a Marginal Risk (Level 1/4) for
Excessive Rainfall on Saturday and Sunday to account for this
moist environment; LREF mean PW values generally range from 1.5 to
1.7 in across the forecast area on Saturday, with marginally
higher PW values on Sunday, especially in the northern portion of
the forecast area. However, given the scattered nature of these
storms, confidence remains low in any forecast rain totals or
flash flood impacts at this time. On Independence Day
specifically, weather will likely be hot (barring convective
interference), with highs ranging from the low to mid 90s.
Scattered storms capable of producing lightning and heavy
downpours will be possible across the forecast area; thus,
interests should remain weather aware during any outdoor
celebrations Saturday afternoon/evening.

Moving into early next week, the aforementioned frontal boundary
should eventually sag south as a slow-moving and weak cold front,
leading to unsettled weather and mild relief from the heat.
Shortwaves could provide reinforcement for additional convective
activity, although model guidance diverges greatly with respect to
the general pattern at this point.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
ISSUED AT 711 PM EDT WED JUL 1 2026

Mainly VFR conditions with light winds are expected through the
period. Mainly valley fog is expected to impact portions of the
region between 04z and 13z with MVFR or IFR reductions, or
locally lower in some cases. The fog could again impact some or
all of the TAF sites during the 08z to 13z timeframe. Opted to
keep TEMPO groups with generally less reductions compared to what
occurred this morning. Any fog should dissipate by 13z in all
locations, with just some diurnally driven cumulus possible
before the end of 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.

&&

$$

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