839
FXUS63 KJKL 261858
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
258 PM EDT Sat Sep 26 2026

.KEY MESSAGES...

- High pressure brings dry and cool early autumn weather into
  early next week.

- Warmer temperatures return from the middle to end of next week,
  along with our next reasonable potential for rain.

&&

.SHORT TERM...(This evening through Sunday night)
Issued at 257 PM EDT SAT SEP 26 2026

This afternoon, a deep and vertically stacked low is located off
the Mid-Atlantic coast; meanwhile, to the west, a high amplitude
midlevel ridge is centered roughly over the Mississippi Valley. At
the surface, high pressure is located over the Great Lakes and
Ontario. Flow around this high is maintaining light north
northeasterly winds across eastern Kentucky, which will work to
keep weather seasonable and dry for the entirety of the forecast
period. Satellite imagery does show some midlevel cloud cover
inching towards our southwestern counties, associated with some
modest midlevel PVA around the periphery of the ridge, although
this energy will only graze the forecast area at best. Otherwise,
skies are expected to be clear; model soundings show a bone dry
environment, with mostly northerly flow throughout the entire
atmospheric column, including extremely dry dewpoints just above
the surface (generally in the -20C range at 850 mb), which should
impede any cloud development. At the surface, NBM dewpoints, which
were already overdone yesterday, were nudged down significantly
to account for this dry air mixing down, and high temperatures
were accordingly nudged up a few degrees as well. Temperatures
should top out in the low to mid 70s this afternoon, with just a
passing high cloud or two outside of our southwestern most
counties.

Overnight, conditions look mostly ideal for a ridge-valley split,
with weak winds and mostly clear skies. MOS guidance is quite
aggressive with lows tonight (suggesting some sites could cool
into the 30s); however, some deterministic guidance depicts very
modest CAA continuing on ridges overnight, which could prevent
valley lows from dipping as low as MOS suggests. Further
complicating the minT forecast, ensemble guidance shows a signal
for potential stratus building in late, which could also work to
limit cooling. With such a dry air mass in place, uncertainty in
this outcome was too high to include these clouds in sky grids for
now, with just typical valley fog expected. Even so, a more
modest ridge-valley split was favored, with valley temperatures
falling into only the low to mid 40s. Any fog should dissipate
shortly after sunrise.

With a stagnant blocking pattern in place, Sunday`s weather looks
to be more of the same, with sunny seasonable weather, light
mostly northerly winds, and dewpoints in the 40s, again nudged
down from the overly moist NBM. Overnight, lows look to trend a
degree or two warmer. A weak pressure gradient and mostly clear
skies will favor the development of another ridge-valley split.
Lows will fall into the low to mid 40s in valley locations, with
the most impactful weather again being typical valley fog
formation.


.LONG TERM...(Monday through Saturday)
Issued at 257 PM EDT SAT SEP 26 2026

The period begins Monday morning with a mature cyclone located in
the vicinity of New York City, while an upper ridge axis extends
from west Texas northeast to the Upper MS Valley. Surface high
pressure ridging extends south from southern Canada down the west
side of the Appalachians, including across eastern Kentucky. An
upper level low over Nevada and southern California is progged to
be upstream of the upper ridge across the middle of the country.
Models show this low helping to draw tropical moisture from
Hurricane Polo northeastward into the northwestern Mexico and the
Southwest CONUS as the week progresses.

Models show the Southwest CONUS upper low weakening gradually as it
moves to the center of the country as the week progresses.
Meanwhile, northerly upper flow between the downstream upper low and
upstream ridge gradually transitions to west/southwesterly flow
aloft mid to late week as a new downstream ridge develops over the
TN/OH Valley, bringing a notable rise in temperatures and humidity.

Confidence in the forecast is fairly high through Thursday, with
some differences emerging late week that can primarily be explained
by differences mainly in the Canadian ensembles showing more
troughing across the Great Lakes and Midwest compared to ridging on
the GEFS and EPS. With the models trending more towards ridging mid
week in most modeling, the onset of low precipitation chances has
been pushed back now to Thursday from the west, with gradually
increasing PoPs to 50 percent by the end of the long term Friday
night. Meanwhile, temperatures will undergo a fairly abrupt warming
trend from Monday through Thursday, peaking in the 80s Thursday,
before a cooling trend begins Friday, with abruptness depending
on which solution verifies. Overnight lows will also rise
significantly from the 40s to begin the week to the 60s for the
second half of the week.


&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 134 PM EDT SAT SEP 26 2026

Expect VFR conditions and light north to northeasterly winds at
TAF sites through the period. Tonight, valley fog looks to
develop around 05Z, fully dissipating by 14Z, which could bring
localized IFR to MVFR conditions, although TAF sites should
remain unaffected. Some models do suggest low stratus could
develop overnight, roughly from 08Z to 14Z, although uncertainty
remains too high to include these clouds in TAFs at this time.

&&

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

&&

$$

SHORT TERM...FAGAN
LONG TERM...CMC
AVIATION...FAGAN/CMC