373
FXUS63 KJKL 121807
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
207 PM EDT Sat Sep 12 2026

.KEY MESSAGES...

- Unsettled weather will continue through tonight as a front
  remains stalled in the vicinity of eastern Kentucky.

- Locally heavy rainfall is expected at times this afternoon into
  the evening, which could lead to isolated to scattered flash
  flooding.

- Temperatures will increase to well above normal, or even near
  record, levels by the middle of next week.

&&

.UPDATE...
Issued at 740 AM EDT SAT SEP 12 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 zones.

&&

.SHORT TERM...(Today through Sunday)
Issued at 440 AM EDT SAT SEP 12 2026

08Z sfc analysis shows the wavy front now lifting north through
southeast Kentucky. This boundary is rather quiet at the moment
though storms are found off to the northwest of the JKL CWA - but
is expected to get more active later this morning. In the
meantime, under a sky with multiple layers of clouds, areas of fog
have developed and are not just confined to the valleys. However
the densest of the fog is found in the deeper locations closer to
the rivers. Currently, temperatures (and dewpoints) are fairly
uniform throughout eastern Kentucky - generally in the upper 60s
to lower 70s.

The models, and their individual ensemble suites, remain in
pretty good agreement aloft through the short term portion of the
forecast. They all depict a local weak 5h trough working west to
east through the Ohio Valley today and tonight. At the start of
the forecast period we see another batch of mid level energy over
western Kentucky this morning. This will work east through the
day in tandem with the lower heights of the weak 5h trough. The
core of the trough will pass through our area later tonight so
that its lower heights and bits of energy will be around during
the bulk of our daytime heating cycle helping to support
convection when combined with the anticipated instability peak
this afternoon. By the middle of the night, 5h heights will begin
rising over the area in response to strong ridging from the
Desert Southwest working back northeast to the Southern Plains and
extending its influence into the Tennessee Valley by Sunday
night. Considering the small model spread, mainly unadjusted NBM
data were used for the forecast grids this morning. With the high
dewpoint air in place again there was little opportunity to
improve temperatures or dewpoints through the weekend. As for
PoPs, included radar details in the near term along with the
latest CAMs guidance to enhance the NBM PoPs through tonight.

Sensible weather will feature another likely wet and stormy day
with the nearby front, passing upper support, instability for the
afternoon, and persistent PWS near climatological maximums in the
1.8 to 2.0+ inch range through this evening. The shower and storm
chances will start to wind down later tonight - mainly reduced to
just showers as the daytime instability wanes. Look for areas of
fog to develop again tonight between the bouts of pcpn. Sunday
will be mostly dry in the wake of the departing sfc low, though a
stray shower cannot be ruled out. WPC has continued the northeast
portion of the area in a Slight Risk for excessive rainfall but
have us un-highlighted for the rest of the period. Accordingly,
we do have a Flood Watch kicking in at noon today for our
northeast counties where the rainfall has been a bit more abundant
these past few days. Any training could result in isolated
flooding in this area through the first part of the night.
Elsewhere, localized flooding will also be possible but the ground
there is a bit less primed.

The main adjustments to the NBM starting point were for PoPs -
adjusting them for near term radar trends and then through tonight
via the inclusion of guidance from the latest CAMs. Temperatures
and dewpoints were not adjusted much considering the high
moisture content in the air.

.LONG TERM...(Sunday night through Friday)
Issued at 345 AM EDT SAT SEP 12 2026

At the start of the long term period, a midlevel ridge will be
centered over the Southern Plains, with midlevel troughing over
the Great Lakes region. Eastern Kentucky will initially find
itself between these two features, with relatively zonal flow
aloft; however, by Monday, ridging is expected to push eastward
and amplify. Meanwhile, at the surface, a cold front will
initially be located near the Ohio River. Throughout Monday, this
front will sag southward, ushering in cooler and drier air as
winds shift to become more northerly to northeasterly. This will
keep highs closer to average in the northern forecast area, likely
in the low 80s, with warmer temperatures farther south near the TN
line. Even so, rain chances with this front look to be relatively
low, and any mentionable PoPs remain confined to the northern
portions of the forecast area.

Following this frontal passage, there is high confidence an
anomalously strong ridge will build into the area and linger
through at least midweek, with LREF mean 500 mb heights peaking
Wednesday at 599 dam (representing the 100th percentile compared
to climatology!). This will suppress convection and keep
temperatures unseasonably hot, more characteristic of the middle
of summer than mid September. Highs look to peak Wednesday,
generally in the low 90s across the forecast area. Also, given
increasingly southwesterly winds around a surface high over the
Mid Atlantic, dewpoints will quickly rebound, rising into the
upper 60s to perhaps low 70s on Tuesday and Wednesday.
Accordingly, although lows will be in the upper 50s to low 60s on
Monday night, they look to trend warmer into the midweek, with the
caveat that clear skies and diminishing winds overnight will
promote ridge valley temperature splits that should keep valleys a
few degrees cooler than NBM output would suggest. Cooling
overnight will be accompanied by typical valley fog formation,
particularly within mainstem river valleys.

Model spread increases significantly from Thursday onwards as
shortwave energy moving through the base of a digging trough will
attempt to suppress our pesky ridge. There is virtually no model
agreement regarding how quickly the ridge begins to weaken, with
some deterministic guidance showing the forecast area near the
base of a trough by the end of the period, while other guidance
keeps the ridge around seemingly indefinitely. Still, rain chances
are favored to return near the end of the period as another cold
front approaches.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 207 PM EDT SAT SEP 12 2026

Widely varying conditions were in place across eastern Kentucky at
TAF issuance time with IFR or worse in ongoing convection while
generally MVFR to VFR conditions were noted elsewhere. Look for
ongoing convection to gradually wind down this evening, but that
will probably just allow for areas of fog and low stratus to
develop overnight. Winds will be south to southwest around 5 knots
or less today becoming light and variable tonight. However,
briefly strong and erratic winds will be possible within/near
storms through the evening.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
Flood Watch until 1 AM EDT Sunday for KYZ044-052-104-106-107-109-
110-119-120.

&&

$$

UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...FAGAN
AVIATION...GEERTSON