362
FXUS63 KJKL 302358
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
758 PM EDT Thu Jul 30 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
  Wednesday.

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

&&

.SHORT TERM...(This evening through Friday night)
Issued at 339 PM EDT THU JUL 30 2026

At 19Z, visible satellite shows mostly sunny skies with a cu field
streaming across the area from the north, as they rotate around
nearby high pressure. Analyzing the 500-mb height charts, some
prominent features are the upper level low over northern New
England, within a subsequent trough extending south along the
Eastern US coastline. Weak ridging can be seen further west over the
Upper Midwest, and Mississippi Valley. An area of low pressure over
the Northern Plains is north of a southwestern high over New Mexico.

Stepping through this evening and Friday, the overall pattern shifts
eastward, as the coastal trough continues to progress towards the
Atlantic. High pressure continues to build into the Ohio Valley and
Tennessee Valley as the Northern Plains low pressure begins to dig
into western portions of the Ohio Valley.

For sensible weather, expect mostly clear skies this evening, as
temperatures cool from their current upper 70s to lower 80s into the
lower 60s along ridge tops, and upper 50s in valleys. Patchy river
valley fog is expected to develop overnight, before mixing out
between 8 and 9 am Friday morning.

With high pressure briefly building in on Friday, mid to upper 80s
are expected under light easterly winds. Skies will be a mix of sun
and clouds, with notable increasing clouds heading into the evening
and overnight hours. This is due to the approaching system.
Temperatures will cool into the mid to upper 60s. As the surface low
digs into the Mid-Mississippi Valley overnight, the systems warm
front and eventual cold front will approach portions of Kentucky
towards Saturday morning. Some isolated to scattered showers and
storms will be possible heading into Saturday morning, mainly along
and west of the Cumberland Plateau.

.LONG TERM...(Saturday through Thursday)
Issued at 455 PM EDT THU JUL 30 2026

The long-term period opens 12Z Saturday with a positively-tilted
500 hPa shortwave trough digging into the Mid-Mississippi Valley
behind shortwave ridging departing east of the Appalachians. An
~1003 mb area of low pressure will be situated over southwest
Illinois just ahead of the shortwave trough. A warm front will
extend southeast from the low across Middle Tennessee and Northern
Georgia, while a cold front arcs to the south into the Missouri
Bootheel and then southwest to over Northern Texas. Further to the
north, 500 hPa troughing is focused over and adjacent to Hudson
and James Bay, supporting a second cold front draped from a
surface low over southern Baffin Island southward to the Ottawa
Valley, and then westward across the Upper Great Lakes and
Dakotas. Meanwhile further west, an ~599 dam high is situated
over the Lower Colorado River basin while a ridge axis extends
northeastward across the Canadian Prairie Provinces.

The most active weather of the long-term forecast will occur during
the first two days of the period. The aforementioned shortwave trough
will continue to amplify as it becomes more meridionally oriented on
Saturday and Saturday night while its attendant surface low
tracks over the Lower Ohio Valley. This will send the warm front
pushing into eastern Kentucky while the trailing cold front
catches up and occludes. At the same time, the northerly trough
will also amplify across the Great Lakes and capture some or much
of the vorticity energy associated with the more southerly
shortwave. There is admittedly substantial disparity from model-
to-model and run-to-run regarding how much upper-level support
remains with the closed-off low or perturbation that lingers. In
any case, the much diminished upper-level support of the surface
low leaves it to meander southward and dissipate early next week
along with its associated frontal structures as relatively subtle
weakness lingers in the heights aloft. Meanwhile, a new area of
low pressure will form near or over the Eastern Great Lakes and
New England as the northern stream trough pulls away to the east.
The system`s cold front will sag southward into the Central
Appalachians through mid-week but stagnate there. Another upper
level trough and cold front may approach the Ohio Valley around
and just beyond the end of the forecast period.

The main concern during the long-term period will be the potential
for heavy rainfall on Saturday into early Sunday as PWATs rise to
1.75 to 2.00 inches (or 90th to 95th percentile relative to climo) in
the WAA regime ahead of the surface low. WPC`s Slight Risk (2 of
4) for excessive rainfall was expanded to cover all but the
easternmost portions of Pike County. Efficient warm layer rainfall
processes combined with the potential for training convection in
a high PWAT environment are all supportive of a locally heavy
rainfall threat, possibly leading to instances of flooding. A
notable mitigating factor is the antecedent drying ongoing prior
to the event---the 3-hour FFG currently ranges from 1.75 to 2.50
inches across most of the JKL CWA and will likely improve further
with an additional 36 to 48 hours of drying. As for any severe
weather potential, shear may be sufficient for limited
organization, but overall destabilization remains highly
uncertain, especially east of I-75. If any strong to severe storms
materialize, they would most likely occur west of I-75. PWATs
fall back somewhat Sunday and Sunday night as the surface low
weakens and dissipates, but the second cold front fails to press
far enough south to drop PWAT levels below seasonal norms.
Lingering moisture combined with the remnant weakness aloft will
still combine with the daily heating cycle to keep the continued
threat for primarily afternoon and evening convection in the
forecast from Monday onward.

In sensible weather terms, clouds and shower and thunderstorm chances
increase on Saturday, with coverage peaking Saturday night
followed by a secondary peak on Sunday afternoon. Some of the
showers and thunderstorms could produce torrential downpours,
especially on Saturday and Saturday night. It will be muggy both
weekend days with high temperatures mainly in the lower 80s and
lows not far from 70F. Looking ahead to the new work week,
temperatures start the week with highs near 80F on Monday before
slowly warming into the mid to upper 80s by Thursday, while
nighttime lows range from the 60s to near 70F. Scattered showers
and thunderstorms are expected each day as well, primarily during
the afternoon and evening.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 755 PM EDT THU JUL 30 2026

VFR conditions continue to prevail through the 00z TAF period.
This evening`s satellite imagery depicts a diminishing diurnal cu
field across the area. A few of these clouds may drift in the
vicinity of the TAF sites at the immediate start of the period,
but clear skies should be the predominant conditions overnight
given the close proximity of a surface high pressure system.
Expect river valley fog to develop after 03z, but this is not
currently forecast to impact any of the TAF sites. Fog will lift
and then mix out by 14z tomorrow. After that, expect similar VFR
ceiling and vsby conditions to continue area-wide. Winds will
remain light, but they will likely veer towards a more easterly
and then southerly orientation by the end of the period.


&&

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

&&

$$

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