556
FXUS63 KJKL 111754
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
154 PM EDT Fri Jul 11 2025

.KEY MESSAGES...

- High temperatures will be near normal through the week though
  they may trend above normal over the weekend and early next
  week.

- Chances for showers and storms persist through the upcoming
  weekend and into week, mainly during each afternoon and
  evening. These chances peak Sunday to Monday.

&&

.UPDATE...
Issued at 857 AM EDT FRI JUL 11 2025

Fog has rapidly diminished and the special weather statement for
fog will be allowed to expire at 915 AM EDT. Weak convection has
already initiated over portions of the upper Cumberland River
Basin this morning, courtesy of a subtle disturbance departing
into Virginia and Tennessee. Additional activity is favored later
this morning and afternoon as the next disturbance, currently over
Western Kentucky and Southern Indiana, approaches. See the
previous update for overall shower and thunderstorm expectations
with that perturbation.

UPDATE Issued at 759 AM EDT FRI JUL 11 2025

Fog, locally dense, is beginning to lift across eastern Kentucky
at mid-morning and should dissipate quickly over the next hour.
Otherwise, expect a mostly sunny day with the lower end chances
for pop-up showers or thunderstorms. The greatest opportunity for
showers and storms (40 to 50% chance) will be over the Cumberland
Basin east of I-75 and also over the South/Middle/North Fork
Kentucky river headwaters. The lowest rain chances (under 20%) are
north of the Mountain Parkway. The disturbance responsible for
forcing is subtle and heights will overall be on the rise with
weak lapse rates, so expect any shower and thunderstorm activity
to be anemic.

UPDATE Issued at 1215 AM EDT FRI JUL 11 2025

No significant changes were made to the forecast with mainly just
the inclusion of the latest obs and trends for the T/Td/Sky grids
keeping the PoPs to a minimum but also retaining the areas of
dense valley fog. These minor adjustments have been sent to the
NDFD and web servers along with a freshening of the zones, HWO,
and SAFs. An SPS was also issued for the areas of dense valley
fog.

UPDATE Issued at 730 PM EDT THU JUL 10 2025

23Z sfc analysis shows weak high pressure over the area -
stretched through the Southeast. This is keeping convection to a
lesser extent with respect to coverage and intensity compared to
yesterday evening. In addition, skies are mostly clear and the
winds light - away from any showers or storms. Currently,
temperatures are running in the low to mid 70s where the rain
occurred most recently and in the upper 70s and lower 80s
elsewhere. Meanwhile, dewpoints are generally still in the sticky
low 70s. Have updated the forecast mainly to add in the latest obs
and trends for the T/Td/Sky grids but also to fine tune the PoPs
per the latest radar loop and CAMs guidance. Did also maintain
the more prevalent fog depiction for the Wx grids compared to the
last few nights. These adjustments have been sent to the NDFD and
web servers along with a freshening of the zones and SAFs.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 330 PM EDT THU JUL 10 2025

Widely scattered showers and thunderstorms (often referred to as
garden variety for their disorganized nature) continue across
parts of central/eastern Kentucky at mid-afternoon. This activity
is occurring as a dampening upper-level trough, extending
southward from Quebec, crosses the Central Appalachians. This
convection is also generally ahead of the last associated weak
mid-upper level vorticity max, which is passing over Central
Kentucky. Meanwhile, there is little in the way of discernible
features in the surface pressure field as it remains dominated by
mesoscale diurnal and convective effects. A stalled frontal
boundary well north of the Ohio River has little direct impact on
our sensible weather. PWATs have dropped sharply since yesterday
and now range from 1.4 to 1.6 inches while flow in the 850-300 mb
layer favors cell motions to the east at about 10 to 15 kts,
limiting hydrologic concerns to very isolated poor-drainage/urban
ponding and elevated small stream flows in locations affected by
the most persistent convection. MLCAPE is modest around 1,000 to
1,500 J/kg and shear is minimal, minimizing the severe weather
concern. Temperatures are seasonable, ranging from the mid 70s in
areas recently affected by convection to the mid 80s where
sunshine has been more prevalent.

As the trough and its associated vorticity energy slowly slide
eastward, low to mid-level heights will begin to rise as weak
subsidence leads to a mid-level capping. This will cause showers
and thunderstorm coverage to gradually wane through the remainder
of the afternoon and evening and actually allow a weak tongue of
high pressure to build along the Central and Southern Appalachian
Mountains tonight. The combination of clearing skies, light winds,
and ample lingering low-level moisture will set the stage for
efficient radiation fog formation. Locally dense fog is not out of
the question as nighttime minimum temperatures are forecast to
fall 2+ degrees below crossover temperatures in many areas. On
Friday, heights continue to rise (aside from a weak upper level
perturbation in the afternoon) while surface ridging slides a
little further east ahead of the next weak upper level trough
approaching from the Central Plains. Limited deep convection is
possible again on Friday afternoon/early evening with the passing
disturbance and differential heating. However, lean CAPE profiles
and minimal shear will keep any activity sporadic and weak. After
bottoming out between 1.2 and 1.4 inches tonight/early Friday,
PWATs will again creep higher amidst southwesterly return flow,
likely exceeding 1.5 inches toward dawn on Saturday.

In sensible terms, look for leftover showers and thunderstorms to
dissipate heading through the evening. Partly cloudy skies yield
to areas of fog overnight. Some of that fog could become locally
dense, especially in valleys. Low temperatures are forecast to be
in the mid to upper 60s. On Friday, mostly sunny skies might be
interrupted in some locations by isolated to scattered showers and
thunderstorms. Otherwise, it will be seasonably hot with highs
from 85 to 90 degrees. Friday night is shaping up similar to the
prior night with any late-day convection giving way to mostly
clear skies and areas of fog overnight. The fog is likely to be
more confined to the river valleys than tonight. Look for Friday
Night temperatures to settle back into the mid 60s to near 70
degrees.

.LONG TERM...(Sunday through Friday)
Issued at 154 PM EDT FRI JUL 11 2025

Models are in relatively good agreement on a zonal mid-level jet
stream remaining well north of the area along the US/Canada border
through the period, with persistent weak mid-level troughing
remaining within a relatively weak flow regime aloft either just
upstream or over the area. A weak surface front will attempt to push
across the area Monday, but models are increasingly coming into
better agreement that this front will not completely clear the area
and in fact may stall across eastern Kentucky. This will keep mostly
diurnally-driven convection in the forecast for much of the long-
term period.

Highest PoPs will be Sunday ahead of the front under a weak warm-
advection regime, and then again Thursday as warm advection begins
to increase ahead of a stronger system that appears poised to arrive
toward next weekend (Days 8-10). Lowest PoPs appear to be Tuesday
into Wednesday, but there is an increasing trend in these PoPs from
the previous package.

Highs will generally reach the mid- to upper-80s most days, but may
reach the lower 90s Tuesday and perhaps Wednesday given height
rises, and especially if any drier air can result in less cloud
cover and precipitation. This may bring a subsequent increase in the
heat risk as forecast heat index values begin to approach 100
degrees in the warmest locations, especially Wednesday into
Thursday of next week.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 630 AM EDT FRI JUL 11 2025

All IFR/MVFR fog at a few sites will clear by 13Z with a renewed
chance for diurnal convection later in the afternoon. Winds will
generally be under 10 kts through the period, except locally
stronger and erratic near thunderstorms. Could see another round
of IFR/MVFR vis with patchy fog towards the end of the TAF period.

&&

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

&&

$$

UPDATE...GEERTSON
SHORT TERM...GEERTSON
LONG TERM...CMC
AVIATION...WFO SGF