Somerset, Kentucky 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

129
FXUS63 KJKL 060624
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
224 AM EDT Wed May 6 2026

.KEY MESSAGES...

- Widespread showers and a few storms can be expected through
  Thursday morning, bringing beneficial rainfall to the area.

- Cooler, below normal, temperatures settle in Thursday through
  Friday. Temperatures Thursday night drop into the mid to upper
  30s in valleys, bringing the potential for fog and localized
  patchy frost.

- Periodic chances for showers return for the upcoming weekend
  into early next week.

&&

.UPDATE...
Issued at 1140 PM EDT TUE MAY 5 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
as well as a tweaking of the PoPs per the current radar and CAMs
guidance. These minor adjustments have been sent to the NDFD and
web servers along with a freshening of the SAFs and zones.

UPDATE Issued at 730 PM EDT TUE MAY 5 2026

23Z sfc analysis shows a wavy cold front just northwest of the
JKL CWA this evening. A large area of mainly showers is a
associated with this boundary and is starting to brush into
northwest parts of the area. Expect this to encroach more and
overtake eastern Kentucky through the night with some thunder
chances, as well. In the meantime, currently, temperatures are
running in the lower 60s northwest with that rain to the low 70s
in the southeast. Meanwhile, amid southerly winds of 5 to 10 mph,
dewpoints vary from the low 50s west to the mid 40s east. Have
updated the forecast mainly to add in the latest obs and trends
for the T/Td/Sky grids as well as to fine tune the PoPs and
thunder chances through the night per radar and CAMs guidance.
These minor adjustments have been sent to the NDFD and web servers
along with a freshening of the HWO, SAFs, and zones.

&&

.SHORT TERM...(This evening through Wednesday night)
Issued at 243 PM EDT TUE MAY 5 2026

This afternoon mid and high level clouds continue to work into the
forecast area from the west, as shower chances increase heading into
the evening. This is due to an area of low pressure in the
vicinity of James Bay; straddling the border of Ontario and
Quebec. The surface cold front extends southwest from southern
Quebec (Ottowa), back towards the Lower Great Lakes, through the
Ohio Valley including southern Indiana. This front is evident on
a 18Z surface pressure map, as well as the wind field.

A secondary area of low pressure, located over Central Oklahoma is
expected to propagate northeast through the day and ride along the
cold front of the first mentioned system. Showers and possibly an
embedded rumble of thunder is expected later this afternoon into
the evening, as the cold front nearly stalls over the IL-IN-OH-KY
border. With the area under persistent southwest flow ahead of the
stalled cold front, ample moisture will work into the area.

PWAT in the 12Z BNA sounding was 0.75 inches and model guidance has
PWAT modifying up to 1.25 to 1.50 inches However, given the limited
amount of CAPE (a few hundred Joules), It remains unlikely that
number will be fully realized. Model to model runs of this system
have also been trending downward for rain amounts. As of the 12Z run
of the HREF, the probability of seeing 1 inch of rain through 8 AM
Thursday morning (or now through Wednesday night), remain around 55-
85% along and south of an area extending from Berea to Jackson, to
Prestonsburg. Areas north of this area generally have a less than
15% chance of seeing that much rainfall. The area north of the above
mentioned line has a 20-50% of seeing at least 0.75 inches of
rainfall, and generally a 70-95% chances of seeing 0.50 inches of
rainfall.

The cold front will take its time working through Eastern Kentucky
on Wednesday, and eventually do so later that evening into Thursday.
A shift in winds from southwesterly this afternoon to northerly
through Wednesday will usher in some cooler air. One can expect
afternoon highs in the mid to upper 70s with increasing clouds this
afternoon and showers, possibly with embedded thunder anytime after
7-8 PM this evening, increasing overnight and through Wednesday.
Temperatures tonight fall into the lower 50s to upper 50s from north
to south.  Winds will shift from a southerly direction to a
northwesterly direction by tomorrow morning where showers and storms
continue. Temperatures warm into the low 60s to low 70s from north
to south, dropping into the mid 40 to low 50s from north to south in
the evening Wednesday.

.LONG TERM...(Thursday night through Tuesday)
Issued at 224 AM EDT WED MAY 6 2026

The long term forecast period opens on the backside of the shortwave
troughing responsible for the active weather described above. As
that feature ejects east, subtle midlevel height rises and a
building surface high pressure system suggest that a clearing trend
will emerge on Thursday evening. A shift to more northwesterly winds
aloft will advect a drier, continental airmass into the region, but
surface winds will be light and variable given the weak pressure
gradient. Collectively, this suggests that Thursday night`s sensible
weather will be driven by localized topographic effects.

Assuming that clearing trend comes to fruition, ridge-valley
temperature splits are expected to emerge after sunset on Thursday
evening. Sheltered and shaded hollows will see the most efficient
radiational cooling and thus the coolest overnights. Temperatures in
the mid 30s there could pose a risk for patchy frost development by
Friday morning. In the main stem river valleys, the presence of
additional moisture should insulate MinTs in the upper 30s/lower
40s. Given that similar post-frontal set-ups have recently produced
patchy valley fog, fog was added to the grids along the Cumberland,
Kentucky, Red, Licking, and Levisa/Tug Fork Rivers with tonight`s
forecast package. Greater fog coverage may be needed in future
forecast updates, especially if grounds are wet by any additional
rainfall on Thursday. The risk for frost/fog lowers as elevation
increases, and ridgetop locales are the most likely to remain in the
mid 40s on Thursday night.

Thursday night`s surface high is forecast to quickly pass through
the forecast area on Friday. Its proximity allows Friday`s daytime
hours to stay dry and mild, but southwesterly surface flow emerges
on its backside by Friday afternoon. These winds will advect a
relatively warmer airmass into the region for the end of the week.
Highs rebound into the upper 60s/lower 70s on Friday afternoon, and
lows stay near the 50 degree mark on Friday night amidst increasing
cloud cover. A midlevel disturbance arriving around midnight on
Saturday morning will work with the warmer air to produce some AM
showers and storms, but misalignment with the diurnal instability
cycle and the shallow nature of the antecedent moisture return will
limit the intensity ceiling of this convection. LREF mean PWATS peak
at a piddly 0.80 inches in the Bluegrass on Saturday morning, then
decrease the further one goes into the higher terrain of SE KY on
Saturday afternoon. The better forcing with this system is also
contained to northern portions of the forecast area, as the parent
disturbance aloft looks to eject NE and abandon the surface boundary
on Saturday afternoon. Any early-day activity along the I-64
corridor should accordingly weaken as it moves deeper into the CWA
after sunrise, and Saturday`s PoPs accordingly follow a North-South
gradient. Rain chances above 40% are limited to locations north of
the Mountain Parkway, and the Cumberland River Basin may stay dry.

The above boundary becomes diffuse across the forecast area on
Saturday night, resulting in seasonably mild and calm conditions.
Another night of ridge-valley splits is possible, but with less
concern for frost and fog. Given the lack of post-frontal cold air
advection, temperatures are generally forecast to remain above the
50 degree mark on Saturday night. This gives Sunday`s temperatures a
head start and sets the stage for more widespread showers and storms
on Sunday afternoon/evening. Sunday`s setup features more vertically
stacked southwesterly flow and thus a more effective warm air
advection/moisture return regime. Breezy southwesterly flow will
yield highs in the upper half of the 70s and dewpoints in the upper
50s/lower 60s on Sunday afternoon. LREF mean PWATs climb to around
1.15 inches in this same time frame, which suggests that Sunday`s
showers and storms will be more meaningful than Saturday`s. The risk
for severe weather does not currently appear particularly high, but
the currently-available ML/AI/analog guidance collectively resolves
marginal-esque probabilities in Southern Kentucky with this setup.
It is possible that those pieces of guidance are picking up on the
potential for a more favorable strong storm environment to emerge on
the warm side of the previous day`s stalled out boundary. The LREF
joint probabilities for marginally favorable convective parameter
spacing (>500 J/kg CAPE, <-25 J/kg CIN, and > 30 knots effective
bulk shear) are in the 30-40% range south of the Mountain Parkway.
While the higher probabilities are confined to the south in the
Tennessee Valley, the progression of Saturday`s boundary and the
related convective model trends on Sunday are worth watching.

Broader longwave troughing digs into the Greater Ohio River Valley
on Monday, setting up a postfrontal northwesterly flow regime from
the surface to the midlevels. Expect a cooler and drier airmass to
move into the commonwealth for the start of the next work week as a
result. After skies clear from west to east on Monday, drier weather
persists on the backside of that trough through Tuesday. The
progressive nature of the overarching synoptic pattern means that
the aforementioned trough is likely to lift into New England by mid
week though. Quasi-zonal flow should emerge over the forecast area
in its wake, but forecast models diverge from there. There is
significant disagreement surrounding the timing and evolution of a
potential system at the very end of the period, but there is a
stronger signal for a warming trend out ahead of it. The CPC Days 8-
14 Temperature Outlook, which begins at the end of the period on
Wednesday, May 13th, suggests that temperatures are trending above-
normal for mid-May in Eastern Kentucky. This is good news for our
frost-sensitive interests, but they are encouraged to pay close
attention to Thursday night`s frost forecast in the mean time.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 154 AM EDT WED MAY 6 2026

Scattered showers are over eastern Kentucky at the 06Z TAF
issuance but more widespread showers and isolated thunderstorms
are approaching from Central Kentucky with an approaching cold
front. With this activity, conditions (VFR at the start of the
period) will deteriorate to MVFR/IFR from northwest to southeast
through daybreak. Shower activity should become more confined to
areas near and southeast of an SJS-JKL-SME line by 15Z as the cold
front sags through the forecast area. A weak wave riding the
boundary may push shower activity back to the north for several
hours toward the end of the TAF period but substantive rainfall should
still remain southeast of I-64. Winds will generally be variable
to southerly at 5 to 10 kts early this morning but a strong LLJ
will cause LLWS for most of the pre-dawn timeframe. Sfc winds
will eventually shift to a more northwesterly direction as the
front starts to move in after 10Z.

&&

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

&&

$$

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