816
FXUS63 KJKL 291413
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1013 AM EDT Wed Jul 29 2026

.KEY MESSAGES...

- Drier weather with modestly lower humidity will prevail through
  the end of the work week.

&&

.UPDATE...
Issued at 1013 AM EDT WED JUL 29 2026

Fog has mixed out across the area, and the SAFs have been updated
to remove fog wording. Today, mostly sunny skies are expected
with some hazy skies due to wildfire smoke from out west. The
forecast has been updated to incorporate the latest observational
and model data. No major changes were made.

&&

.SHORT TERM...(Today through Thursday)
Issued at 320 AM EDT WED JUL 29 2026

07Z sfc analysis shows high pressure building into the Ohio
Valley in the wake of a cold front departing Kentucky to the
southeast. Plenty of leftover moisture in the boundary layer has
been prompting the development of dense valley fog for the
southeast portion of the state - locations that saw more sustained
rain on Tuesday afternoon. Despite the changing air mass it has
been another mild and muggy night for most locations with
temperatures (and dewpoints) in the upper 60s to lower 70s, amid
light and variable winds.

The models, and their individual ensemble suites, remain in fairly
good agreement aloft through the short term portion of the
forecast. They all depict Kentucky still between two distinct 5h
features - a large, persistent ridge over the southwest that
shifts a bit more southwest with time and broad troughing
holding over the Northeast with a recently closed off low
rotating its way through eastern New York before drifting to
Massachusetts by Thursday afternoon. This keeps the our state in
fairly fast, northwest mid-level flow that will carry some weak
impulses through during the next 48 hours. By the end of the
period, a new shortwave is noted working east through the
Northern Plains - destined to have an effect on our weather by the
weekend. Given the small spread among the models aloft through
the rest of the work week, the NBM was used as the starting point
for the forecast grids with only minor adjustments needed. These
are mainly improvements to the nocturnal temperatures from the
NBM by adding terrain details consistent with a good setup for
radiational cooling.

Sensible weather features terrific weather once the early morning
valley fog clears out each day through Friday. This fresh air
mass is enough to wonder if we have just seen the last cold front
of the spring season or the first one of autumn. I`ll go with the
latter and welcome the less humid conditions today and Thursday
along with plenty of sunshine and temperatures peaking below
seasonable norms each afternoon. Tonight, we will see a small
ridge to valley temperature split set up under conditions of
mostly clear skies, light winds, and the expectations of valley
fog formation.

The main adjustments to the NBM starting point were add some
terrain based details to temperatures tonight and lower afternoon
dewpoints on account of the drier air mass advecting into the
area. PoPs were not adjusted much - with the NBM ones in the
reasonable low single digits or zero through the period.

.LONG TERM...(Thursday night through Tuesday)
Issued at 335 AM EDT WED JUL 29 2026

The main change to the grids for the first part of the extended
forecast this morning was primarily to include more in the way of
terrain distinctions into temperatures for Thursday night and the
first part of Friday night along with drier afternoon dewpoints
through the rest of the work week. The westward retreat of the
strong 5h ridge to the west looks to allow shortwaves in northwest
flow to start cutting to the west of eastern Kentucky and
likely setting up lower heights for the region with a trough axis
through western Kentucky by the end of the weekend. Accordingly,
sfc high pressure in place for the end of the work week looks to
keep the weather quiet, dry, and rather pleasant. Then return
flow moisture and the upper level dynamics return storm chances
to the forecast starting Saturday along with a potential for
excessive rainfall.

The previous long term discussion follows:

The long-term period opens Thursday morning with a deep trough axis
extending from Quebec southward to along the Mid-Atlantic and
Southeast US coast. Meanwhile, an ~596 dam high is in place over
the Southern Rockies with broader ridging across much of the
Central and Western CONUS. This leaves the Ohio Valley in a zone
of subsidence on the eastern side of the ridging, corresponding to
an area of surface high pressure. There is also a shortwave
trough riding over the top of the ridging across the Dakotas at
the start of the period.

Aside from some nighttime and morning fog in the typically favored
river valley locales, fair weather will be found across eastern
Kentucky through Friday as surface high pressure crests over and
just northeast of the JKL CWA. This will keep relatively cool
temperatures in place for both Thursday and Friday with highs in
the lower to mid 80s and lows in the mid 50s to near 60F. Dew
points falling into the upper 50s to lower 60s will make it feel
quite comfortable.

Looking ahead to the weekend and early next week, the shortwave
trough over the Northern Plains will dig southeastward and close
off into a low over the Mid-Mississippi Valley. A weak area of
surface low pressure will develop ahead of this feature over the
Central Plains on Thursday night into Friday, then occlude and
decay near or over the Commonwealth early next week. This system
will wrap higher humidity levels back into eastern Kentucky while
also bringing rounds of convection. As a result, daily high
temperatures will remain on the cool side, generally in the lower
to middle 80s, while nighttime lows moderate to between 65 and
70F.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
ISSUED AT 800 AM EDT WED JUL 29 2026

VFR conditions were noted at the TAF sites at forecast issuance.
Fog is present in the deeper valleys but should lift/burn off with
little or no impact on the TAF terminals. Once the fog
dissipates, VFR conditions under a scattered cu field will persist
area-wide through the remainder of the day with weak northerly
winds.

&&

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

&&

$$

UPDATE...GINNICK
SHORT TERM...GREIF
LONG TERM...GEERTSON/GREIF
AVIATION...GEERTSON