Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

278
FXUS63 KJKL 170757
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
357 AM EDT Fri Jul 17 2026

.KEY MESSAGES...

- Hot and humid weather continues today, with widespread heat
  indices in the 90s to near 100 degrees.

- An anomalously moist airmass over the region should lead to
  rounds of storms through Sunday, some of which could produce
  strong wind gusts and heavy rainfall and localized flooding.

- A series of systems cross the region early next week, bringing
  rounds of storms Tuesday to Wednesday, followed by relatively
  cooler and drier weather for the second half of next week.

&&

.UPDATE...
Issued at 1150 PM EDT THU JUL 16 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.
These minor adjustments have been sent to the NDFD and web servers
along with a freshening of the HWO, SAFs, and zones.

UPDATE Issued at 735 PM EDT THU JUL 16 2026

23Z sfc analysis shows high pressure west of the state with a dome
of high heights over eastern Kentucky. This is keeping most of
the area free of convection except for some pinprick cells that
are nearly stationary providing a scant few locations a narrow
bout of heavy rain. The worst so far has been over central
Jackson County where there was some small response in the creeks
per the CREST analysis, but that cell has since dissipated.
Otherwise, the activity fades out with sunset allowing for mostly
clear skies and the development of fog in the valleys becoming
locally dense - especially for spots that saw any rain today.
Currently, temperatures are running in the still very warm low to
mid 80s. Meanwhile, amid light and variable winds, dewpoints
remain quite high in the low to mid 70s most places. Have updated
the forecast mainly to add in the latest obs and trends for the
T/Td/Sky grids. These minor adjustments have been sent to the NDFD
and web servers along with a freshening of the SAFs and zones.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 420 PM EDT Thu Jul 16 2026

Today`s forecast guidance suite continues to resolve the breakdown
of the elongated ridging circulation responsible for the warm, but
relatively drier, conditions observed across the forecast area
earlier this week. As it does so, synoptic subsidence will weaken
and greater amounts of low-level moisture will return to the column
via west-southwesterly flow around the periphery of the remnant high
centered over the Gulf Coast states. The effects of this subtle
pattern shift are multi-faceted. First, the related increase in
humidity has allowed heat indices to climb into the 90s across much
of Eastern Kentucky this afternoon. A few locales (mostly urbanized
areas in the western portions of our CWA) could record apparent
temperatures in the triple digits, but widespread heat-related
impacts are not expected. This is due to the second effect of the
increased atmospheric moisture -- deeper and more widespread diurnal
cumulus clouds.

Isolated to scattered showers are noted in radar imagery across the
western half of the CWA this afternoon, but the convective activity
thus far has struggled to strengthen into thunderstorms. This is
likely due to the lack of well-defined forcing and wind shear in
today`s set up, but that also means that any taller updrafts will
likely be slow-moving and prone to produce outflow boundaries. The
best chances for more meaningful convection are in our Lake
Cumberland counties, where 19z Mesoanalysis reveals 2000-3000 J/kg
of CAPE and PWATs around 1.8 inches. Thus, we will need to closely
monitor convective trends in southwestern portions of the CWA
through this evening. The 12z HREF LPMM data painted a couple of QPF
bullseyes in this region, and while widespread hydrological impacts
are not expected, minor flooding cannot be ruled out. WPC has
introduced a Marginal (Level 1/4) Excessive Rainfall Outlook in this
region, which seems reasonable given those mesoanalysis parameters.

Aside from a few late attempts at additional updrafts atop residual
outflow boundaries, most of the late afternoon and early evening
convective activity should subside after sunset today. Once it does
so and the lingering cloud debris fizzles out, expect modest ridge-
valley temperature splits and radiation fog formation overnight. It
is plausible that that leftover cloud cover could prevent true
ground fog from occurring, but given the potential for localized
pockets of wet grounds and the higher amounts of boundary-layer
moisture present, relatively greater spatial coverage of patchy fog
was maintained in tonight`s forecast grids. Areal coverage was
contained to the river valleys, and visibility trends will need to
be monitored in area observations. Tonight`s greater fog potential
is the third effect of the shift to a wetter late-week pattern, and
interests with early AM travel plans (and those who are not
necessarily accustomed to driving in the fog) are encouraged to
exercise caution and monitor for any fog-related product issuances.

Similarly hot temperatures will overlap with even greater amounts of
moisture over the forecast area tomorrow. This will allow more
widespread heat indices in the mid/upper 90s, and a larger portion
of the forecast area could approach the triple digits. Expect
convection coverage to accordingly increase to the scattered to
numerous range through, which will once again provide some localized
relief from the heat. Widespread severe weather is unlikely, but any
storms that develop tomorrow are likely to be water-loaded. The HREF
resolves mean PWATs increasing into the 1.9-2.1" range alongside
2000+ J/kg of SB-CAPE across the entire CWA tomorrow afternoon. Bulk
shear remains weak (generally less than 20 knots) and the primary
lifting mechanisms will once again be convection. With all of the
above in place, tomorrow`s storms will need to be monitored for
gusty winds (via wet downbursts and outflow boundaries) and
torrential downpours. Storms are poised to be slow-moving once
again, and if outflow boundaries act as a secondary lifting
mechanism, multiple rounds of storms could affect the same small
stream basins. As such, WPC has outlined the entirety of the
forecast area in a Marginal (Level 1/4) Rainfall Outlook tomorrow.
If tonight`s risk materializes, a corridor of greater flash flooding
could emerge tomorrow. So, interests are encouraged to remain
weather aware for the next 36 hours and have multiple (reliable)
ways to receive weather updates and warnings.

.LONG TERM...(Saturday night through Thursday)
Issued at 345 AM EDT FRI JUL 17 2026

Saturday evening into Saturday night, showers and thunderstorms
are anticipated across Eastern Kentucky, as a shortwave moves
through a positively tilted trough covering much of the Northeast
US and Southeast Canada and an associated cold front sags into the
OH Valley and portions of the Appalachians. Farther upstream, a
high amplitude ridge of high pressure will remain over the
Intermountain West, with the apex of the ridge axis extending well
into Alberta and Saskatchewan. Models also depict another upper
level low on the upstream side of the ridge, located in British
Columbia.

The cold front becomes draped across the Ohio Valley late Saturday
night and is expected to continue to sag south into Kentucky
on Sunday. PWATs will be close to 2 inches ahead of the cold
front, dropping to around 1 inch behind it. Storms ahead of the
cold front Saturday evening through Sunday will have potential to
put down localized heavy rainfall. The WPC has placed most of the
Big Sandy and southern portions of the Kentucky River Basins in a
marginal ERO Saturday through Sunday morning. While all of the
better severe weather parameters (especially shear) stay north of
the forecast area and in the Ohio Valley, there may be a low end
severe threat across Kentucky. Moderate instability is anticipated
and water loaded downdrafts could result in strong to damaging
wind gusts from isolated to scattered activity early Saturday
evening. Locations in and around thunderstorms may experience
gusty and erratic winds. Convective allowing models suggest a
weakening line of storms may move into eastern KY around sunset or
a bit after and there could be a small wind gust threat from this
as well. The SPC has the entire area under a marginal risk for
severe weather Saturday and more southern location on Sunday ahead
of the front where instability may be strongest.

Through Sunday, as the upper level low progresses deeper into
Northeast Canada, the trailing cold front slowly slides off to the
east producing additional showers and storms along the way. The
upper level low over British Columbia rides over the ridge of high
pressure over the Intermountain West. Height rises are expected
Sunday night through Monday, leading to a break in active weather
and mostly sunny skies Monday.

By Tuesday, the upper level low that was modeled to ride over the
ridge, spills down the lee side, into the Great Lakes and Ohio
Valley. Another cold front will pass trough the region Sometime
Tuesday afternoon into Wednesday morning. Some models are suggesting
a great deal of moisture accompanying this system and preceding the
frontal passage. This will continue to be monitored. After showers
and storms move through with the cold frontal passage much drier air
is forecasted to move into the area. This will contribute to a dry
Thursday.

Temperatures generally range from  the mid to upper 80s during the
afternoons and upper 60s to lower 70s at night, at least through
Tuesday. After the frontal passage Tuesday temperatures are expected
to cool some, ranging from the low to mid 80s during the afternoons,
cooling into the lower 60s at night.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 235 AM EDT FRI JUL 17 2026

At issuance time, VFR conditions prevailed at the TAF sites while
valley fog with MVFR to IFR reductions was evident across eastern
and southern river valley locations. Locally wet grounds from
rainfall on Thursday and an overall increase in low-level
moisture relative to 24 hours ago results in rather high
confidence in more extensive fog compared to Thursday morning.
KSME and KLOZ are the most likely TAF sites to be affected by the
greater reductions following rainfall in the vicinity on Thursday
and tempos down to IFR are forecast for both locations with
prevailing MVFR. Elsewhere, with the exception of KJKL, TEMPOs
cover the potential for lesser reductions to MVFR. Once the fog
lifts and dissipates by around 13Z, expect another day of
cumulus development by around 16Z and isolated to scattered
showers and storms between 16Z and 00Z, with spatial coverage
likely the greatest for the more western terminals. Outside of
any showers and storms, expect generally light winds.

&&

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

&&

$$

UPDATE...GREIF
SHORT TERM...MARCUS
LONG TERM...GINNICK/JP
AVIATION...JP