166
FXUS63 KJKL 090043
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
843 PM EDT Tue Sep 8 2026

.KEY MESSAGES...

- Temperatures will inch higher through midweek, with humidity
  also climbing a bit into Wednesday and Thursday.

- A cold front moving into the area late in the week will give us
  our next expectation of showers and thunderstorms for Thursday
  or Thursday night.

- Above normal heat and humidity look to continue through early
  next week.

&&

.UPDATE...
Issued at 843 PM EDT TUE SEP 8 2026

Lingering isolated towering cumulus and shower activity has
dissipated with the loss of daytime heating, with just passing
high clouds remaining. The mid-evening update updates hourly
temperatures and dew points using the latest hourly observation as
the initialization to the forecast.

&&

.SHORT TERM...(This evening through Wednesday night)
Issued at 340 PM EDT TUE SEP 8 2026

As of 1930Z, sprinkles and light showers were observed across
southwestern portions of the CWA. Analysis indicates these
showers were driven by weak isentropic upglide near the
850-mb level, though the signal was subtle. Rain activity is
expected to taper off over the next few hours due to a lack
of sufficient forcing and upward ascent. Model soundings
continue to show steep lapse rates and a dry layer within
the lowest 3 km, but deeper convection remains capped by a
strong inversion near 650 mb. Skies should clear out this
evening, leading to decoupled valleys and temperatures
cooling into the low to mid 60s in valleys, while remaining
elevated in the upper 60s to near 70 along ridge tops.
Patchy river valley fog may develop again tonight before
mixing out Wednesday morning.

Wednesday largely remains quiet under high pressure positioned
southeast of the Commonwealth. Warm temperatures in the upper
80s to low 90s are expected with fair skies and dew points in
the upper 60s to low 70s. A strong low pressure system over
Southern Canada will feature a trailing cold front that will
gradually propagate south and east from the Upper Midwest into
the Ohio Valley early Thursday. Showers and thunderstorms
preceding the cold front are expected to work into eastern
Kentucky after midnight Wednesday night, spreading southeast
across the area in the predawn hours Thursday.

.LONG TERM...(Thursday through Tuesday)
Issued at 510 PM EDT TUE SEP 8 2026

The models are in generally good agreement for the majority of
the extended portion of the forecast. Ridging starts out over the
southeastern CONUS as well as the Desert Southwest, while faster
and progressive flow dominates across the northern half of the
CONUS. A notable short wave trough will be aligned from the Upper
Midwest through the middle Mississippi Valley. This feature will
cruise through the Ohio Valley and eventually New England by
Friday. Troughing will be maintained across the Mississippi
Valley Friday into Saturday, as additional short wave energy moves
along the north central CONUS. Meanwhile, a deeper upper level
low will propagate onshore over the Pacific Northwest. As this
feature swings east, more prominent ridging will take hold
downstream across the southeastern CONUS late this weekend and
into early next week.

Sensible weather will feature an active start across eastern
Kentucky for Thursday. A cold front will approach from the
northwest, with more widespread convection moving in from
northwest to southeast during the day. The highest probabilities
will occur north KY-80, with perhaps a slightly slower trend seen
in the latest model guidance. PWATs will peak in the 1.8 to 1.9
inch range, along with the surface boundary aligning more parallel
with the mid and upper level flow. As such, some locally heavy
rainers remain a possibility. Highs on Thursday will be in the mid
to upper 80s. Showers and thunderstorms will continue to threaten
through Thursday evening, although as instability wanes and the
overall forcing diminish, convective coverage should gradually
lessen overnight. Lows Thursday night will range from the mid 60s
north of I-64, to the upper 60s bordering Tennessee. These lows
wound up being just a shade higher than the blended guidance,
given the tendency of the cold front to hang up as it moves across
our region.

This boundary will linger across our southern locales on Friday,
with a resurgence of good chance to likely PoPs seen generally
along and southeast of KY-80. Highs will retreat closer to normal
temporarily, mainly in the low to mid 80s. We will still be under
the influence of troughing aloft on Saturday, although some subtle
500 mb height rises may actually occur. Still, enough low level
moisture will linger to allow for additional diurnally-driven
convection. Similar to Friday, higher PoPs will be favored across
our southeast. From Sunday through Tuesday, ridging will be
building in aloft, keeping convective coverage more limited.
Unfortunately, this will also mean a continuation of above normal
heat and humidity across eastern Kentucky, with highs averaging in
the 85 to 90 degree range each day, and dew points remaining
above 70 degrees at times.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 723 PM EDT TUE SEP 8 2026

VFR conditions are expected through the TAF period with primarily
high clouds. In the near term, patchy low-VFR cumulus and
isolated showers or sprinkles will continue to diminish with the
loss of daytime heating through 01z. Otherwise, light and
variable surface winds are expected through the overnight, but
southwest winds just above the surface of 15 to 25 kts will
develop with the onset of darkness this evening. Some patchy river
valley fog may develop late tonight, but at present is not
expected to cause impacts to the TAF locations. These stronger
southwesterly winds just above the surface will mix out quickly
after ~13z Wednesday, and southwest winds may gust up to 15 to 20
kts through the afternoon at IOB, SYM, LOZ, and SME.

Some CAMS indicate some cumulus and isolated shower activity
moving into western TAF sites after 06z tonight, and this is
something we will monitor but was too low confidence to include in
any TAFs at this time. There is also very low confidence in a
shower or thunderstorm impacting IOB and/or SYM after 21z, so any
mention was not included with this TAF package.

&&

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

&&

$$

UPDATE...CMC
SHORT TERM...GINNICK
LONG TERM...JKL
AVIATION...CMC