774
FXUS63 KJKL 151832
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
232 PM EDT Tue Sep 15 2026

.KEY MESSAGES...

- Above normal temperatures return for today through Sunday.

- Near-record heat is possible Thursday with high temperatures
  expected around 90 degrees in many locations.

- Isolated to scattered showers and storms re-enter the forecast
  Thursday afternoon, then persist into early next week. Most of
  this activity will be limited to the afternoon/evening hours.

&&

.UPDATE...
Issued at 720 AM EDT TUE SEP 15 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 Wednesday)
Issued at 430 AM EDT TUE SEP 15 2026

08Z sfc analysis shows high pressure northeast of the state
controlling the weather for eastern Kentucky. This has resulted in
a cooler night than we have seen in quite some time with clear
skies and areas of fog in the river valleys - locally dense in the
east. Meanwhile, amid light winds, temperatures range from the
the upper 50s north (and in the mid 50s for many of the sheltered
valleys) to the lower 60s over much of the south. Dewpoints
likewise varied from the mid 50s north to the lower 60s in the
south.

The models, and their individual ensemble suites, still continue
to be in close alignment aloft through the short term portion of
the forecast. They all depict an anomalously very strong 5h ridge
over the region holding firm through Wednesday evening with its
core pushing a rare 600 decameters over the heart of the Tennessee
Valley by that afternoon. This will keep all mid level activity
well to the north of the state and the full effect of the ridges
suppression will be in place over eastern Kentucky. Again
considering the very small model spread, much of the forecast
grids came from unadjusted NBM data this morning. However with the
lower dewpoint air in place today did include more terrain
distinction again tonight for the temperatures and lows tonight
while also drying out each afternoon`s dewpoints to account for
deeper mixing and more dry air intrusion that allows. As for
PoPs, again saw no reason not to keep them at the NBM`s near zero
values through the period while high pressure holds at the sfc
from the east and a front stays stuck well to the north.

Sensible weather will feature a decent amount of fog in the river
valleys - thickest in the southeast ones where dewpoint
depressions were smaller. Plenty of sunshine and warm air aloft
will send temperatures soaring across Kentucky today with similar
values anticipated for Wednesday. Both days will see Heat Indices
approach 100 degrees for a few spots in the west, but most of the
area will see values well away from Heat Advisory levels thanks to
drier afternoon humidity levels. For tonight, we can expect more
in the way of radiational cooling and a ridge to valley
temperature split favoring the MOS values for lows in the
sheltered low spots along with more in the way of late night river
valley fog.

The main changes to the NBM starting point were made to
temperatures and dewpoints - adjusted the T grids tonight for more
enhanced terrain details and the dewpoints lower during each
afternoon owing to a mixdown drier air. As for PoPs, they were
kept minimal and pretty much just as populated from the NBM -
again reasonable given the strong ridging holding aloft through
the breadth of the short term forecast period.

.LONG TERM...(Thursday through Tuesday)
Issued at 228 PM EDT TUE SEP 15 2026

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 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 158 PM EDT TUE SEP 15 2026

VFR conditions prevail at all TAF sites throughout the 18z
issuance period. Diurnal cumulus development has been observed in
this afternoon`s satellite imagery, mostly across Southern
Kentucky. This cu field is not particularly robust due to the
presence of strong midlevel ridging and dry air throughout the
atmospheric column, but it has been included in the TAFs for KLOZ
and KSME. These two terminals are in closer proximity to the
existing and expanding cu field. Light and variable winds are
forecast at all terminals this afternoon. Isolated gusts up to 15
knots cannot be ruled out in locales that experience deeper
diurnal mixing. Once the sun goes down and the diurnal cu/mixing
processes subside, fog will eventually develop in the typical
river valley locales. That fog is not currently forecast to impact
any TAF sites though, and the terminals should remain above P6SM
VFR vsby criteria through tomorrow morning.

&&

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

&&

$$

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