Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

737
FXUS63 KJKL 042328
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
728 PM EDT Sat Jul 4 2026

.KEY MESSAGES...

- Heat headlines remain in effect through 9 PM EDT tonight. Highs
  near 90 degrees and muggy conditions will produce peak heat index
  values in the 90s to over 100 degrees before dropping off tonight.

- Mainly dry, warm, and humid conditions will favor fireworks
  displays this evening, outside of an isolated shower or storm.
  River valley fog develops overnight.

- Scattered to numerous showers and storms return Sunday and
  Monday as a slow-moving cold front arrives. A few storms could
  produce isolated strong winds and localized flash flooding.

- The heat wave breaks next week, with daily highs returning to
  near-normal levels in the mid to upper 80s alongside daily
  chances for afternoon showers and thunderstorms.

&&

.SHORT TERM...(This evening through Sunday night)
Issued at 303 PM EDT SAT JUL 4 2026

After scattered early morning convection, ample sunshine has returned
for the afternoon hours of our nation`s 250th birthday. Temperatures
have been much slower to heat up compared to prior days due to
extensive cloud cover and rainfall, mostly ranging in the 80s at
AFD issuance with heat indices in the 90s. While eastern Kentucky
is rain-free everywhere right now, outside of perhaps a few
sprinkles, extensive convection is ongoing just to our east over
Southwest VA and WV. The view from aloft shows subtle 500 hPa
ridging over the Central Appalachians this afternoon with a weak,
embedded 500 hPa vort max noted over central/eastern Kentucky.
Meanwhile, low-amplitude troughing is found over the Mississippi
Valley with a wavy surface front extending from the St. Lawrence
Valley, through the Great Lakes to near Dubuque, IA and then
northwestward into the Canadian Prairies.

Through this evening, sunshine should be overall more prevalent than
clouds with temperatures forecast to approach or exceed 90F. The
morning clouds and convection significantly slowed the onset of
diurnal heating, so confidence in reaching the forecast highs is not
all that high. Thus forecaster confidence in reaching the heat index
thresholds of the ongoing heat headlines is also on the lower side.
However, given the widespread outdoor activities this holiday
afternoon, the impact of the heat likely warrants keeping the heat
products in place, not to mention remaining consistent with
neighboring WFOs. As for any shower and thunderstorm chances, those
appear minimal, especially west of US-23 where forcing most
limited and dew points have dipped back into the upper 60s to low
70s, limiting instability. While a brief shower or thunderstorm
cannot be ruled out in this area, if one does occur it would
likely be highly isolated. Further east, the aforementioned upper-
level vort max as well as mesoscale effects from convectively
induced boundaries and differential heating may afford a renewed
threat for showers and thunderstorms over or just east of the Big
Sandy basin this evening.

Otherwise, aside from the possibility of a rogue shower or storm,
partly cloudy skies are expected this evening and tonight, allowing
for an ideal time for fireworks displays in most places. It will be
warm and muggy with low temperatures not far from 70F. Fog is
probable in the favored river valley locales. The upstream trough will
approach overnight and begin to amplify, but any associated convection
probably won`t reach eastern Kentucky until after daybreak in our
western counties and perhaps the afternoon hours over southeastern
Kentucky. Overall the parameter space on Sunday looks to feature
seasonably high PWATs (1.7 to 1.9 inches), weak mid-level lapse
rates, moderate instability, and weak shear. Convective mode will
likely be pulsy and a few cores could become marginally strong to
severe, perhaps sufficient for isolated downbursts with the
collapse of water-loaded updrafts. Convection will also be slow-
moving, so if it sets up over an area where soils are more
saturated (like where it rained this morning), isolated flooding
could also be a concern. Coverage of storms is expected to be
scattered to numerous during the afternoon and early evening.
Temperature-wise, it wont be quite as hot as recent days with
values mostly in the 80s to near 90F. The 500 hPa trough deepens
further just to our west Sunday night, but convection is overall
favored to diminish as the environment becomes quite fully worked
over and diurnal instability wanes. This will leave behind
variable cloud cover and the renewed opportunity for fog formation
in the favored river valleys and other areas that receive
substantial rainfall. Sunday night will also be on the mild and
muggy side with forecast lows from 65 to 70F.

.LONG TERM...(Monday through Saturday)
Issued at 424 PM EDT SAT JUL 4 2026

The long-term period opens Monday with the prior week`s heat wave
just a memory. The 04/12Z model suite analysis beginning at 12Z
Monday shows a split flow pattern over the Eastern Great Lakes with
a positively-tilted trough extending southwestward into the Mid
and Lower Mississippi Valley while a ridge axis extends northward
to over northern Greenland. Meanwhile, an ~593 dam high will
reside over the Upper Rio Grande Valley beneath a trough over
Central Canada. At the lower levels, the pattern is subtle. A weak
area of low pressure is likely to be in the vicinity of southern
Indiana with a cold front extending southwest into the Ozarks.

Working through the upcoming work week, guidance is in fair agreement
showing the upper-level trough propagating eastward with its axis
crossing the CWA on Tuesday, causing the aforementioned cold
front to drop through the forecast area. The notable exception is
the ECMWF deterministic holding back a weak closed low over the
Mid-Mississippi Valley which would inhibit the cold front`s
southward progression. Diurnally modulated deep convection is
probable on both Monday into Tuesday with the frontal boundary
nearing and dipping into the area. Greater uncertainty on overall
convective coverage comes on Wednesday and depends on whether the
front effectively dips south of the Commonwealth or gets hung up.
In either case, the rain chances appear to increase again heading
later in the week as the trough over Canada begins to dig
southeastward and the Southwest US high shifts westward and then
begins to amplify, pumping up a robust, positively tilted ridge
axis from the Desert Southwest to southern Nunavut. At the
surface, the front over us or to our south turns frontolytic as a
new cold front settles southward toward the Ohio Valley.

In terms of heavy rainfall, a Marginal (level 1 of 4) ERO is in place
through Monday night to highlight the threat of isolated flash
flooding should storms become persistent over a given location ahead
of the first cold front. A renewed low-end excessive rainfall threat
may return late in the week as moisture returns ahead of the
second boundary, but that is beyond the WPC ERO window at this
point. Temperatures through the period will settle back into the
mid to upper 80s for daily highs each afternoon while nighttime
lows retreat into the 65 to 70F range for most locales. The
typical valley fog is likely on any night with substantial
clearing.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
ISSUED AT 728 PM EDT SAT JUL 4 2026

VFR conditions are occurring across all TAF sites with this
issuance as surface high pressure remains dominant. However,
convection is developing and these showers and storms could bring
brief category reduction if one should move over a terminals; as
well as, gusty and erratic outflow winds. With this issuance, KSYM
is the only site that`s forecast to see convection before it
dissipates after sunset. Mostly clear skies are expected tonight
with locally dense river valley fog that may sneak into a terminal
but confidence is low; therefore, was left out of the TAF. Better
shower and storm chances arrive early Sunday afternoon. Outside
of convection, winds are forecast to be light and variable through
the period.


&&

.JKL WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 9 PM EDT this evening for KYZ044-050>052-
058>060-068-069-079-080-083>085.

Extreme Heat Warning until 9 PM EDT this evening for KYZ086>088-
104-106>120.

&&

$$

SHORT TERM...GEERTSON
LONG TERM...GEERTSON
AVIATION...VORST