150
FXUS63 KJKL 280253
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1053 PM EDT Sun Sep 27 2026

.KEY MESSAGES...

- High pressure brings dry and cool early autumn weather to begin
  the week.

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

&&

.UPDATE...
Issued at 1053 PM EDT SUN SEP 27 2026

Late evening observations were blended into the forecast without
any substantive changes.

UPDATE Issued at 729 PM EDT SUN SEP 27 2026

With clear skies and light winds in place, the common update for
quickly dropping valley temperatures around sundown has been done
in the very near term. There are no substantive changes for
tonight as a whole.

&&

.SHORT TERM...(This evening through Monday night)
Issued at 246 PM EDT SUN SEP 27 2026

Our taste of early fall weather will continue through the short
term period, with plenty of sunshine and mild temperatures
expected. A midlevel ridge, not quite as amplified as in previous
days, sits over the Great Plains, with a deepening midlevel trough
over the Pacific Coast. Meanwhile, a deep vertically stacked low
is positioned just off the Northeast coast, with surface high
pressure over the Great Lakes region. This coastal low will
meander around the NYC area, blocking the eastward progression of
the ridge and its associated surface high before eventually
lifting northward late Monday. This will allow ridging to finally
build eastward by the end of the short term period, with the
surface high roughly centered over Ohio by early Tuesday.

Today, continued northerly to northwesterly winds around these
features will maintain seasonable temperatures and reinforce a
fairly dry air mass. Model soundings show northerly flow
throughout nearly the entire atmospheric column, which should work
to limit moisture even aloft; HREF mean PW values are generally
around 0.5 this afternoon, abnormally low compared to climatology
(roughly the 20th percentile). Current observations do show a
slight uptick in surface dewpoints north of the forecast area,
with the 12Z ILN sounding depicting more moisture than in previous
days, particularly around the 850 mb layer (although these levels
will still be fairly dry). This should keep dewpoints slightly
higher than yesterday, although NBM dewpoints were still blended
down to account for expected mixing (particularly in our
southwestern counties, which have consistently been drier in this
pattern due to little rainfall in recent days). This enhanced
moisture has allowed a few cumulus to form, with the highest
concentration of these clouds in the eastern portion of the
forecast area where satellite imagery shows slightly better low
level moisture. Otherwise, expect a sunny and dry day. High
temperatures were nudged up a few degrees to adjust for the NBMs
moist bias, particularly in the southwest of the forecast area,
with temperatures expected to reach the mid 70s in many locations.
Overnight, light winds and clear skies should favor a modest
ridge valley split. MOS guidance, which suggests lows in the upper
30s to low 40s in sheltered locations, has been too aggressive in
this pattern, especially given the slightly higher moisture in
our traditionally cooler eastern valleys. Thus, a more modest
split was favored, with valley temperatures falling into the low
to mid 40s, in tandem with typical fog formation.

The pattern changes very little by Monday, but with high pressure
shifting east, winds will gradually become more north
northwesterly. High temperatures will be roughly a degree or two
warmer than today, ranging from the mid 70s in the east to the
upper 70s near the I-75 corridor. Again, NBM dewpoints were likely
too moist, and were blended down while maxTs were raised
slightly. Increasing moisture embedded within this deep
northwesterly flow could allow for more high clouds than today;
otherwise, sunny weather is expected. Lows will also be warmer
than in previous days as ridging continues to build east, though
high pressure overnight will favor the development of yet another
ridge valley split, with the coldest valleys falling into the mid
to upper 40s.

.LONG TERM...(Tuesday through Sunday)
Issued at 246 PM EDT SUN SEP 27 2026

While surface high pressure will remain over eastern Kentucky
yielding continued sunny skies Tuesday, warm advection will begin
to gradually increase through midweek as upper ridging builds
over the Ohio Valley. Meanwhile, a cut-off low over the southwest
CONUS will advect deep tropical moisture northward from the
subtropical eastern Pacific Ocean into the middle of the country
ahead of a cold front over the Southern Plains, with models
struggling significantly in the evolution of this low as the week
progresses, causing increasing uncertainty downstream over eastern
Kentucky. At the same time, model ensemble systems also differ on
the speed, location, and strength of a northern stream system and
associated cold front traversing the northern part of the
country, especially as it moves across the Great Lakes and Ohio
Valley, later this week.

While there is significant model uncertainty with how these two key
features evolve, confidence is high in a significant warm-up from
Tuesday through Thursday, with highs peaking Thursday in the mid to
upper 80s, before a cooling trend begins Friday as clouds and rain
chances begin to increase from the west and/or southwest. Whenever
rain does arrive Friday and/or this weekend, there is a good chance
that it will be accompanied by some degree of tropical fetch off of
the subtropical eastern Pacific and/or the Gulf of America, which
could yield (40-50% chance) rain amounts exceeding 0.5" in a 24-hour
period.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 729 PM EDT SUN SEP 27 2026

Valley fog will occur tonight into Monday morning, bringing
localized IFR or worse conditions, especially in southeast KY.
However, TAF sites are unlikely to be affected. Otherwise, VFR
conditions are forecast through the period.

&&

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

&&

$$

UPDATE...HAL
SHORT TERM...FAGAN
LONG TERM...CMC
AVIATION...HAL