Area Forecast Discussion
Issued by NWS Jackson, KY

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311
FXUS63 KJKL 181836
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
236 PM EDT Fri Sep 18 2026

.KEY MESSAGES...

- Well-above normal temperatures persist into the weekend.

- The heat, humidity, and a nearby frontal boundary could foster
  isolated to scattered thunderstorms across the area at various
  times over the next several days.

- Rain chances increase early next week as the persistent upper
  level ridging breaks down.

&&

.SHORT TERM...(This evening through Saturday night)
Issued at 234 PM EDT FRI SEP 18 2026

Weak anticyclonic northwesterly flow continues aloft on the
northeast periphery of a strong upper high over the Arklatex
region, with an embedded shortwave crossing the area today. By
tomorrow, the upper flow trends more westerly and increasingly
cyclonic ahead of a more developed shortwave which looks to be
over the Bluegrass region at 12z Sunday.

At the surface, a weak cold front will continue to move toward the
area from the north, and may reach to the I-64 corridor early this
evening before reaching near the Mtn Parkway corridor later tonight
into Saturday. This front then lifts north Saturday afternoon into
Saturday night as the aforementioned shortwave approaches from the
west Saturday night.

A subtle shortwave rounding the periphery of the upper ridge
combined will continue to tap into a moist and broadly unstable
environment to fire off scattered to numerous showers and
thunderstorms through the remainder of the afternoon into the
evening. This activity will quickly diminish near and after sunset
this evening. Note that remnant shower and thunderstorm activity may
keep northeastern Kentucky counties more stable and less prone to
such development this afternoon.

With a humid air mass in place and cooler air behind the front,
expect fairly widespread low stratus and/or fog, especially along
and north of the remnant frontal boundary. Ridge-valley splits are
likely to be quite low to nearly non-existent. Fog may be dense
particularly where rain is heaviest in the late afternoon and early
evening.

Isolated to widely scattered showers and thunderstorms will develop
again in the afternoon Saturday, with highest chances along the near
the frontal boundary. By late afternoon into the evening, PoPs were
raised higher than the NBM as confidence is increasing that upstream
MCS activity will begin to impact at least parts of eastern
Kentucky. Timing, strength, and location of such activity is in
question but the potential is there for showers and thunderstorms at
anytime through the overnight. Though shear is weak, any clusters of
storms that can organize near or shortly after peak heating will
have the potential to produce gusty winds, with an isolated severe
storm or two possible, though this is low confidence.

.LONG TERM...(Saturday night through Thursday)
Issued at 239 AM EDT FRI SEP 18 2026

Upper level ridging over the southeast CONUS will continue weaken as
we move into the the long term period. Largely zonal flow aloft will
be positioned just to our north at the start of the period. Multiple
weak impulses moving through the flow will help to drive it very
slowly southward as the upper high breaks down. By midweek, some
semblance of an upper low is forecast to evolve near the Great
Lakes, pushing faster flow aloft even further south for late week.

At the surface, this will eventually drive a significant cold front
southward. This boundary should start the long term period to our
north, near the Ohio River or further north, with its true position
possibly somewhat muddled by prior convection. There is potential
for some of this convection to feed off of our heat and humidity on
this side of the front and make it south into our area in the
Saturday night through Monday time frame, but confidence in details
is very low due to mesoscale influences which would be in play. The
greatest POP looks to be as the front pushes through. Models have
not come into agreement yet, with cold fropa timing likely to be in
the Tue-Wed time frame.

Noticeably cooler air should arrive behind the front as sprawling
surface high pressure sets up in the vicinity of the Great Lakes and
southeast Canada for late week. Our POP drops off with the change in
air mass, but some light precip won`t be completely ruled out,
depending on the evolution of the persistent upper low/trough and
any impulses rotating around it.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 139 PM EDT FRI SEP 18 2026

At 17z, remnant shower activity continues on a dissipating trend
from this morning`s shower and thunderstorms. However, scattered
to numerous showers and thunderstorms will likely redevelop by
20z as strong diurnal heating and a humid atmosphere increases
instability. While most of the daylight hours should remain VFR,
showers and storms could lead to MVFR or lower reductions. Light
and variable winds currently will increase to around 5 kts from
the northwest to northeast as we near peak heating/mixing.
Locally stronger and erratic winds are possible near convection.

Fairly widespread low stratus and/or fog is expected for much of
eastern Kentucky tonight, especially in the wake of today`s
convection, with reductions to MVFR/IFR and perhaps lower are
possible, especially between 06z and 14z, with improvements back
to VFR conditions afterward through the end of the TAF period as
low clouds burn off with daytime heating.

&&

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

&&

$$

SHORT TERM...CMC
LONG TERM...HAL
AVIATION...CMC