Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

646
FXUS63 KJKL 021955
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
355 PM EDT Thu Jul 2 2026

.KEY MESSAGES...

- Hot and humid weather persists at quite oppressive levels through
  the rest of the week.

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

- Thunderstorms from Friday to the middle of next week may produce
  strong to locally damaging wind gusts and locally heavy
  rainfall, potentially leading to a few instances of flooding.

&&

.UPDATE...
Issued at 230 PM EDT THU JUL 2 2026

Once again, temperatures have been slower to rise compared to
guidance in several locations likely due to recent wetter weather
with steep mid level lapse rates in excess of 7C/km helping
sustain cumulus a b it longer today as compared to Wednesday.
However, most locations have reached around 90 or the lower 90s
with heat indices between the upper 90s and 107. Hourly grids were
freshened up based on recent trends as temperatures and heat
indices should climb a couple of more degrees for most.

UPDATE Issued at 719 AM EDT THU JUL 2 2026

Did a quick update to adjust to the latest obs and trends this
morning. Given there is once again patchy dense fog opted to hoist
an SPS again this morning through 13Z to cover this hazard.
Outside this no major impacts weather wise before heat builds in
through through the late morning and afternoon.

&&

.SHORT TERM...(Today through Friday)
Issued at 253 AM EDT THU JUL 2 2026

The early morning surface analysis shows high pressure right
overhead, with strong mid-level heights at 596mb at 00Z at near by
upper air sites. The mid-level heights are centered to our east just
a bit based on the 00Z RAOB data. These heights are continuing to
run around 99th percentile for this time of year. There is good
agreement for these features to remain overhead or just to the east
for the short term period. The broken record of river valley fog
will roll on this morning and will be the biggest impact to start
the day. This fog will lift out through the morning and should be
sunny areawide by 9-10 AM.

Then yet another day of summer heat will be in store for eastern
Kentucky. The NBM continues to run on the hotter side of guidance,
so did opt to make some adjustments toward some of the other model
blends through the short term to lower afternoon highs in
coordination with surrounding WFOs. Even so ample moisture
combined with afternoon highs in the low to mid 90s will lead to
heat indices once again in the triple digits to near 105. This
will be day 3 of 4 consecutive days with heat indices in the 105
degree range. Much like yesterday forecast soundings show the
potential for some diurnally driven cumulus to develop again this
afternoon, but these will remain mostly capped noted by strong
inversion within the forecast soundings. However, some of the CAMs
are noting some convection developing along the Cumberland
Plateau in Tennessee and these could slowly migrate northward
toward the Lake Cumberland region late this afternoon. Given this
did opt to blend the NBM PoPs toward the short term blends to
account for this potential. The SPC marginal risk does touch our
Tennessee border areas, but confidence remains low on just how
much convection we see today given the overall varying looks from
the CAMs and generally capped environment. Then tonight, expect
another night of clear skies, with yet another round of river
valley fog possible. The lows will only fall into the lower 70s to
perhaps upper 60s, with small ridge/valley splits of maybe 1-2
degrees in most cases.

By Friday, the previously mentioned mid-level high will shift east
some. This could open the door for a little more in the way of
convective coverage, with shortwave spokes dancing around the
upper high. This as most of the CAMs start to show convection
developing in our terrain near the Virginia/Tennessee border and
migrating northwest. The SPC does expand the marginal risk area
wide for Friday given ample moisture and strong surface heating
combining to lead to MUCAPE values in the 4000 J/kg range.
However, given the lack of shear with nothing notable from the 0-6
km levels storms would struggle to organize, but if storms can
develop we will have DCAPE values in the 1000-1300 J/kg range
which would be supportive of isolated damaging wind threat.
Outside this, the hot and moist environment will lead to day 4 of
4 for the potential for heat indices near to around 105 degrees.
Therefore, the Excessive Heat Warning will remain in effect
through Friday.

.LONG TERM...(Saturday through Thursday)
Issued at 351 PM EDT THU JUL 2 2026

The long term period opens in the midst of a pattern change as the
upper level ridge continues to break down over eastern Kentucky.
By Saturday, the center of the 500 mb high will no longer be
directly overhead, providing some relief from the heat. However,
temperatures will still be firmly above average across the
forecast area on Independence Day, with highs likely in the low to
mid 90s, and given dewpoints in the upper 60s and low 70s,
conditions will still be quite muggy. In conjunction with this
heat and moisture, a deeply unstable environment will build, and
with minimal capping, scattered diurnally driven convection is
expected to develop. This high instability, in addition to steep
low level lapse rates, will promote a wet microburst risk with any
storms that do form; accordingly, the Storm Prediction Center has
introduced a Day 3 Marginal Risk (Level 1/5) for isolated
damaging winds. With weak flow aloft, shear will be minimal, and
convection will tend towards being pulse-like in nature. Notably,
SPC does highlight the potential for a more organized damaging
wind threat if an MCS can develop upstream, although confidence is
very low in this outcome. In addition to the low end severe risk,
moisture will be favorable for torrential downpours; LREF mean PW
values are generally in the 1.5-1.7 in range on Saturday evening,
indicating an anomalously moist environment (generally in the
70th-80th percentile compared to climatology). To cover the
potential for heavy rain and perhaps isolated flash flooding in
the strongest storms, the Weather Prediction Center has maintained
a Day 3 Marginal Risk (Level 1/4) for Excessive Rainfall across
the entire forecast area. Although isolated severe weather and
flash flooding are possible, it is worth noting that thunderstorm
activity is not currently expected to be widespread in the
afternoon and evening; thus, although some areas will be impacted
by storms, it appears likely that most areas will remain dry.
Regardless, interests are encouraged to remain weather aware for
the duration of any outdoor Independence Day celebrations.

Following typical valley fog development overnight Saturday, Sunday
will present another opportunity for showers and storms. With the
upper level ridge mostly decayed over our area, convective
coverage will likely be higher than Saturday. A broad area of
height falls will overspread the area as an upper level low
translates east towards Lake Superior, with general troughing over
the Midwest. At the surface, an area of low pressure will be
located in the Great Lakes, with a frontal boundary draped to the
west. This boundary will gradually sag towards Kentucky as the
upper level low translates to the southeast, providing an
additional mechanism for showers and storms. The environment will
still be anomalously moist, with LREF mean PW values marginally
higher than the day before in the 1.6-1.8 in range (largely
ranging from the 80th to 90th percentile across the forecast
area); thus, storms will again be capable of producing heavy rain.
Accordingly, WPC has kept eastern Kentucky in a Marginal Risk
(Level 1/4) for Excessive Rainfall on Sunday and Monday, although
flash flood potential will depend on whether multiple rounds of
showers and storms end up tracking over the same area. Boundary
parallel flow further indicates that flooding from training
convection could become a concern, particularly with such a slow
moving front, although confidence in storm timing remains low in
such a nebulous pattern. Thankfully, this pattern should bring
further relief from the heat, with highs dipping into the low 90s
on Sunday and some areas seeing highs in the 80s on Monday (and
storm activity could reduce these temperatures further!).

Looking ahead, rain chances will continue through the end of the
period. Models generally depict the aforementioned front continuing
to sag to the south towards Tennessee, although great spatial
disagreement still exists at this time. Overall, unsettled weather
is expected, with the synoptic pattern featuring troughing over
the eastern CONUS and the potential for additional shortwave
activity. Heavy rainfall will still be a concern as the
environment remains moist, but thankfully, this cloud cover and
rain should further mitigate the heat. Temperatures will continue
to run cooler, and by the middle of next week, highs in the mid
90s should be nothing more than a distant memory.

&&

.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 235 PM EDT THU JUL 2 2026

High pressure will keep the weather quiet, with mostly VFR
conditions through much of the period. Cumulus has developed,
and has mixed into the VFR range and this should gradually mix out
over the first few hours of the period. We continued to stick
close to a persistence forecast for tonight, with some temporary
restrictions not out of the question at some point between 08Z and
13Z at some or all of the TAF sites though confidence was not high
enough to include reductions at this juncture. Non TAF site
locations could drop to the IFR range or possibly lower. Any fog
should lift around 13Z and we will be left with mainly VFR skies
as diurnally driven cumulus develop between 3 and 5 kft agl level
through the afternoon. The winds will remain generally light and
variable.

&&

.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...JP
SHORT TERM...DJ
LONG TERM...FAGAN
AVIATION...JP