416
FXUS63 KJKL 300130
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
930 PM EDT Wed Jul 29 2026

.KEY MESSAGES...

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

- Thunderstorms are possible at times from Saturday through
  Tuesday.

- Locally heavy rainfall is possible on Saturday and Saturday
  night and could lead to isolated instances of flash flooding.

&&

.UPDATE...
Issued at 930 PM EDT WED JUL 29 2026

Tonight`s forecast remains largely on track, with area
observations beginning to reflect the anticipated ridge-valley
temperature splits. Valley locales have already dipped down into
the 60s, and as daylight is lost, this cooling trend will persist.
Eventually, temperatures in the valleys will approach the
dewpoints and yield fog into tomorrow morning. Fog coverage
should be relatively lower than it was last night given the drier
grounds and the persistent northerly flow observed across the area
today. Synoptic conditions still favor formation in the river
valleys, where the localized moisture source may work to produce
patches of more significant visibility reductions. This is typical
for summertime in Eastern Kentucky, and the persistence of this
pattern into tomorrow makes for a seasonably pleasant end to the
month of July.

&&

.SHORT TERM...(This evening through Thursday night)
Issued at 336 PM EDT WED JUL 29 2026

A closed low over New York continues to bring 500-mb troughing
across much of the Eastern US. A ridge of high pressure further west
remains over the Central Plains and Intermountain West. Western and
Central Kentucky are modeled to be situated near the inflection
point between these two larger 500-mb height features. Overnight
into Thursday, the closed low will slowly progress further into
New England, as high pressure continues to build over New Mexico.
While this occurs, a shortwave passes around the high, through
the Great Basin, and into the Northern Plains. This will flatten
the ridge of high pressure heading into Thursday evening.

For sensible weather across Eastern Kentucky, temperatures currently
range from the upper 70s to low 80s. With light northerly winds and
mostly clear conditions, temperatures are expected to cool into the
upper 50s in valleys to lower 60s along ridge tops. Some patchy fog
may develop this evening, but should mainly be confined to the
typical mainstem river valley locations. Thursday, after morning fog
mixes out, temperatures warm into the low 80s under mostly sunny
skies and light northerly winds. Some patchy fog may develop into
the evening, but may be more sparse, being another day removed from
any recent rainfall. Temperatures are expected to cool into the
upper 50s to low 60s.

.LONG TERM...(Friday through Wednesday)
Issued at 357 PM EDT WED JUL 29 2026

The long-term period opens Friday morning with an upper-level trough
axis extending from Atlantic Canada southward along the Atlantic
Seaboard. Meanwhile, an ~588 dam high will be in place over
Arizona and New Mexico with broad ridging extending to the north
across the Canadian Prairies. Less prominent ridging extends east
and northeast from the high to across the Mid-Mississippi Valley,
Ohio Valley, and beyond into Southwest Quebec. A sharpening and
digging upper-level shortwave trough is also sliding across the
Upper Midwest through the eastern side of the ridge. At the
surface, high pressure, centered over West Virginia, dominates the
the Central Appalachians and into adjacent regions. Meanwhile,
low pressure is consolidating from Kansas to Iowa ahead of the
shortwave trough (and will become our most significant weather
maker of the forecast period).

The surface high pressure system and associated shortwave ridging
aloft will shift east to along the Atlantic Seaboard by the end
of the day Friday while the deepening 500 hPa shortwave dives
southeast and the attendant surface low tracks across the mid-
Mississippi Valley, moving directly over the Commonwealth Saturday
night. Some of the energy within this trough will be captured by
a broader 500 hPa trough pivoting through Eastern Canada and the
Great Lakes. Guidance suggests whatever energy remains pinches off
into a closed low that then retrogrades toward the Lower Mississippi
Valley early next week and becomes entrapped under the eastward-
building 500 hPa ridging. As a result, the surface low will
occlude, sink southward, and decay on Monday. Meanwhile, a cold
front associated with the trough passing through the Northeast
will brush to our north and east.

As the low pressure system approaches, southerly flow will send PWATs
rising to 1.75+ inches (around 80th percentile relative to climo) on
Saturday, but those higher values will be short-lived overall as
drier air sinks back in from the north behind the retrograding low
and trough brushing to our north. WPC has a Marginal to Slight
Risk for Excessive Rainfall over the JKL CWA on Saturday and
Saturday night to account for the potential of locally heavy
rainfall, which is the main concern in the long-term period.
However, several days of antecedent drying as well as the overall
progressive nature of the system should help mitigate hydro
concerns. Fortunately, the instability and shear parameter space
remains weak and that should preclude any notable severe
convective weather threat.

Sensibly, look for increasing clouds on Friday and Friday night with
high temperatures in the lower to mid 80s and low temperatures in
the lower to middle 60s. Rain chances return on Saturday and peak
at categorical PoPs Saturday night and early Sunday morning.
Daily rain chances follow for Monday through Wednesday, but
convective coverage should be more sparse and modulated by the
diurnal heating cycle. Temperatures will continue to run in the
lower to middle 80s for highs each afternoon (except upper 70s for
some locations on Sunday), while nighttime lows dip into the 65
to 70 degree range for most.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
ISSUED AT 815 PM EDT WED JUL 29 2026

VFR conditions prevail for the duration of the 00z TAF period.
While a few shallow cumulus clouds and some smoke/haze are
visible across the area in this evening`s satellite imagery, these
features will have little to no near-surface level impacts. Light
northerly winds continue through tomorrow, albeit with a diurnal
decrease in magnitude tonight. This should allow for fog to
develop in the river valleys, but the fog is not currently
expected to affect any of the TAF sites. Observational trends will
need to be monitored overnight though, as there are still low-end
(<=30%) probabilities for minor MVFR vsby reductions at terminals
like KLOZ, KSME, and KSJS. Once any valley fog mixes out tomorrow
morning, expect similar conditions to prevail through the end of
the period.

&&

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

&&

$$

UPDATE...MARCUS
SHORT TERM...GINNICK
LONG TERM...GEERTSON
AVIATION...MARCUS