511
FXUS63 KJKL 130034
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
834 PM EDT Sun Oct 12 2025

.KEY MESSAGES...

- Dry, seasonably pleasant weather continues across Eastern
  Kentucky through the upcoming work week.

- Temperatures will remain near or just above climatological
  averages for the duration of the forecast period.

- While confidence in specific details remains low, the next
  chance of showers/storms will come next weekend.

&&

.UPDATE...
Issued at 834 PM EDT SUN OCT 12 2025

Clouds are eroding as they try to progress further west over the
the forecast area. However, where they are prevalent, they are
greatly slowing the normally quick evening drop for valley temps
in our eastern counties. Have modified forecast lows to keep
eastern valleys a bit milder than what was earlier forecast.

UPDATE Issued at 712 PM EDT SUN OCT 12 2025

Low clouds are arriving from the east, on the back side of the
coastal storm, more aggressively than was forecast. The forecast
has been updated to account for this, but confidence is not high
for how well they hold together and how far west they make it.
Models don`t seem to be handling them particularly well. Where
clouds are prevalent, they will also impede temperatures from
falling and subsequent fog development. These parameters may need
to be subsequently looked at for updating as well in a little
while.

&&

.SHORT TERM...(This evening through Monday night)
Issued at 343 PM EDT Sun Oct 12 2025

Eastern Kentucky is currently positioned in between a deepening non-
tropical low centered over coastal North Carolina and a building
ridge of high pressure over the Greater Ohio River Valley. In
sensible weather terms, this translates to mostly clear skies, with
a few fair weather diurnal cumulus clouds noted in the Bluegrass
region and low/mid level clouds draped over WV and VA. The previous
short term forecast for the remainder of this afternoon and evening
remains on track. Temperatures are on track to warm into the low to
mid 70s before sunset, and light/variable winds will adopt a more
northeasterly component to them overnight as the aforementioned
coastal low shifts closer.

Tonight, these northeasterly winds are expected to advect some low-
level moisture into the region around the far northwestern periphery
of the coastal low. This could lead to the development of a low
stratus deck into tomorrow morning, and forecast guidance has
trended towards this solution as the day has progresses. The
baseline NBM data used to populate the forecast grids picked up on
this trend, and the forecast depicts increasing cloud cover over
northeastern portions of the area after sunset. Synoptically, this
can be attributed to both the wraparound moisture and a subtle
inverted surface trough/convergence zone between the two
aforementioned dominant synoptic features. The signal for cloudy
skies is strongest in the HREF between 2am and 9am, and confidence
in clouds is highest northeast of the I-75 corridor. Before this
time frame, antecedent dryness and clear skies should favor ridge-
valley temperature decoupling. The more sheltered valleys should
quickly cool off into the 50s after sunset, and this may lead to
overnight valley fog formation, especially in our SW counties. The
signal for increasing cloud cover is intriguing from a fog/ridge-
valley split forecast lens. If a widespread low stratus deck comes
to fruition earlier than anticipated or if the spatial coverage of
these clouds is greater than what is currently forecast, low
temperatures could be more insulated and fog formation would be less
likely. If the stratus deck under-performs, the fog could be more
widespread and more radiational cooling could be realized. Thus,
confidence in tonight`s forecast is lower than usual, and the
sensible weather will be highly dependent upon observed trends in
sky cover after dark.

The effects of tonight`s convoluted sky forecast cascade into
tomorrow`s temperature forecast. While models are in generally good
agreement that dry air advection via northerly winds and efficient
diurnal warming under otherwise clear skies will prevail eventually,
a lingering stratus deck could dampen the amount of mid-day warming
realized. That could relegate forecast highs to the upper 60s/near
70 in NE portions of the forecast area, but otherwise, temperatures
are expected to climb towards the the low/mid 70s by tomorrow
afternoon. The persistence of a surface high pressure system and
rising midlevel heights from a building ridge aloft support this
notion. Mostly clear skies will favor efficient diurnal processes
tomorrow afternoon and into tomorrow night. In accordance with the
expected degree of boundary layer mixing, dewpoints were slightly
lowered from baseline guidance and winds were bumped up during the
afternoon hours. After sunset tomorrow night, valley MinTs were
lowered into the 40s, ridgetop MaxTs temperatures were raised into
the 50s, and winds were adjusted for localized terrain effects.
Collectively, these edits support the addition of overnight river
valley fog to the end of the short term forecast grids. Overall,
tommorow`s forecast looks like a typical, pleasant Mid-October day
in the commonwealth. However, those with early morning travel plans
tomorrow should prepare for potential visibility reductions, whether
they come in the form of ridgetop-hugging low level stratus or the
classic Eastern Kentucky morning river valley fog.

.LONG TERM...(Tuesday through Sunday)
Issued at 306 PM EDT SUN OCT 12 2025

Ridging prevails through the end of the week, with the exception of
a brief period of northwesterly flow aloft allowing for a backdoor
cold front to move south and then southwesterly across eastern
Kentucky during the day Wednesday. This will bring a cooldown,
especially for overnight lows Thursday night, as cold advection
diminishes and excellent radiational cooling develops. This will
allow for lows in some of our more sheltered valleys to drop into
the mid to upper 30s, which will also mean the chance for some
patchy frost, particularly in our northeastern counties.

Warm advection increases Friday into the weekend ahead of another
potentially stronger disturbance that looks to impact the area next
weekend. This system looks to have pretty good jet support, with the
operational GFS and ECMWF models depicting different solutions
though still roughly in line with the global model ensemble
consensus. Possible impacts include strong to severe storms upstream
over the Mississippi and/or Lower Ohio Valleys at some point,
with more local downstream impacts still to be determined.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 712 PM EDT SUN OCT 12 2025

A ceiling of about 4-5K ft AGL is slowly moving westward into the
JKL forecast area, now as far west as KJKL. Confidence is not very
high concerning the progress of the clouds and how well they will
cold together during the night. If/where they remain dominant,
they will tend to inhibit valley fog development. Elsewhere,
valley fog is expected to develop and spread. The TAF sites with
the greatest potential to be affected by IFR or worse conditions
in fog by dawn are KSME, KLOZ, and KSYM. Any fog will dissipate
on Monday morning, leaving VFR conditions to finish the period.

&&

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

&&

$$

UPDATE...HAL
SHORT TERM...MARCUS
LONG TERM...CMC
AVIATION...HAL