891
FXUS63 KJKL 161438
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1038 AM EDT Wed Sep 16 2026

.KEY MESSAGES...

- Above normal temperatures will persist into the weekend, with
  near record heat possible Thursday.

- The heat and humidity could fuel a few thunderstorms in portions
  of the area at times over the next several days, with the
  probability then rising early next week as the upper level ridge
  currently dominating the area starts to weaken and retreat.

&&

.UPDATE...
Issued at 1038 AM EDT WED SEP 16 2026

Minor updates were made to Sky and PoPs through the afternoon. In
the near-term (i.e., the next few hours) PoPs were raised north
of Interstate 64 as a cluster of showers will graze northern
Fleming County.

UPDATE Issued at 725 AM EDT WED SEP 16 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. With some returns just off to the northwest have added some
small PoPs up there for the next few hours. These minor
adjustments have been sent to the NDFD and web servers along with
a freshening of the zones.

&&

.SHORT TERM...(Today through Thursday)
Issued at 455 AM EDT WED SEP 16 2026

08Z sfc analysis shows high pressure east of the state in control
of the weather for eastern Kentucky. This has resulted in a night
of clear skies and areas of fog in the river valleys - locally
dense. Meanwhile, amid light winds, temperatures are running much
warmer than last night and currently range from the the mid 60s in
the sheltered valleys to the lower 70s over much of the southwest
and on the ridges. Dewpoints varied similarly from the mid 60s in
the valleys to lower 70s in the southwest/Lake Cumberland area.

The models, and their individual ensemble suites, are in close
agreement aloft through the short term portion of the forecast.
They all depict an anomalous 5h ridge peaking in strength over
the region this morning centered just to the southwest of eastern
Kentucky. The JKL CWA`s proximity to the heart of this ridge will
keep all mid level energy well to the north and east of the area
today. The ridge`s core does start to retreat to the southwest
tonight allowing heights to fall locally on Thursday though any
impulses remain out of the picture aloft. Considering the still
quite small model spread, much of the forecast grids came from
unadjusted NBM data this morning. However, for one more night,
did include a touch of terrain distinction for the temperatures
and lows while also drying out the afternoon dewpoints a bit in
order to depict deeper than modeled mixing and somewhat more dry
air making it to the sfc. As for PoPs, with temperature hitting
convective values and some sparse returns in many of the recent
CAM runs for late this afternoon, and again Thursday afternoon,
went ahead and left some 15 to 20% values from the NBM in the
forecast grids.

Sensible weather will feature another morning of valley fog giving
away to mostly sunny skies and quickly warming temperatures. With
dry bulb temperatures peaking in the lower to middle 90s for much
of the area this afternoon heat indices will likely push 100
degrees in the western parts of the area and many of the cities
further east. Conditions will be similar on Thursday with little
relief offered by any few and far between pockets of convection.
For this reason, we will issue an SPS advertising the unseasonable
heat this afternoon and again Thursday afternoon. The very small
shower and storm chances will likely be confined to locations
north of I-64 today while the limited threat stays mainly in the
east on Thursday. Any convection will provide local cooling
effects keeping temperatures there from reaching too deep in the
90s. For tonight - we look for similar conditions with higher
dewpoints providing a floor to the cooler valleys while ridges
stay warm. Again, we anticipate late night river valley fog
becoming locally dense.

The main changes to the NBM starting point were made to
temperatures and dewpoints - adjusted the T grids tonight for some
limited terrain details and the dewpoints slightly lower during
each afternoon owing to a deeper mix-down of drier air. As for
PoPs, the small afternoon chances from the NBM were mostly kept
and smoothed for locations along and north of Interstate 64 today
with similar numbers and smoothing for Thursday. PoPs for both
days also incorporated the most current CAMs consensus guidance.

.LONG TERM...(Thursday night through Tuesday)
Issued at 430 AM EDT WED SEP 16 2026

The extended portion of the forecast looks to be on track with
the idea of the large 5h ridge weakening and drifting southwest
and out of the region enough through the weekend for more
intrusions of energy at mid levels. This should keep a threat of
mainly unorganized convection in the picture even as we remain
unseasonable warm.

The previous long term discussion follows:

High pressure and associated ridge axis aloft over eastern Kentucky
will retrograde and weaken with time, allowing for increasingly
faster west-northwesterly flow aloft through the Ohio Valley as the
long-term period progresses through the weekend.

Warm and mostly dry conditions are expected Thursday as strong mid-
level heights exceeding 597 dm gradually decrease, though low
chances for showers and thunderstorms are warranted across parts
of mainly central and northeastern Kentucky and perhaps extending
south to near the Cumberland Mountains in the afternoon. Highs are
expected to reach the upper 80s to lower 90s across the area, with
max heat indices in the vicinity of 100 degrees.

A passing disturbance to the north and associated jet streak will
push a cold front far enough south Friday to bring increased shower
and thunderstorm chances across the area along with a brief
modest cooldown in the northern half of the forecast area, but
highs will still reach the mid 80s to lower 90s.

Warm advection quickly returns for Saturday, with low PoPs and a
return to highs back into the upper 80s to lower 90s, which looks to
extend through Sunday before a potential cooldown as an upper
trough and associated cold front move into the area and increase
rain chances. While models show broad 40-50 PoPs Monday into
Monday night with relatively good agreement in a system moving
from the central CONUS to the Great Lakes region, model ensemble
systems show significant disagreements on the strength, track, and
timing of the parent trough. Resolving these differences will
likely play a key role in whether those PoPs trend upwards or
downwards as this period nears.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
ISSUED AT 735 AM EDT WED SEP 16 2026

Mainly VFR conditions will prevail through the period, with only
a couple of exceptions. Valley fog will affect some locations,
especially southeast Kentucky, early this morning bringing
localized IFR or worse conditions, but likely not affecting any of
the TAF sites. This fog will clear out by 14Z then a few
thunderstorms may occur near and north of Interstate 64 late this
afternoon and into the evening, bringing isolated sub-VFR
conditions but with probabilities too low to include in the TAFs
as even a PROB30, for now. Meanwhile, winds will be light and
variable through the period - away from any odd thunderstorm.

&&

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

&&

$$

UPDATE...CMC
SHORT TERM...GREIF
LONG TERM...CMC/GREIF
AVIATION...GREIF