365
FXUS63 KJKL 011733
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
133 PM EDT Fri Aug 1 2025

.KEY MESSAGES...

- There is a possibility of showers and thunderstorms at times
  through the next week, mainly during the afternoon and evening
  hours on most days.

- A cold front will bring significant relief from the heat and
  humidity today.

&&

.UPDATE...
Issued at 1043 AM EDT FRI AUG 1 2025

No major changes were made to the forecast. Populated T,Td, Sky
grids with the latest observations and updated diurnal curve as
well.

UPDATE Issued at 730 AM EDT FRI AUG 1 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.
However, did beef up the shower and thunderstorm chances early
for JKL and points east with the front being extra active here.
These adjustments have been sent to the NDFD and web servers along
with a freshening of the zones and SAFs.

&&

.SHORT TERM...(Today through Saturday)
Issued at 415 AM EDT FRI AUG 1 2025

08Z sfc analysis shows a cold front settling slowly south through
eastern Kentucky to start the new month. This is being trailed by
high pressure descending from the western Ohio Valley. Still a
few lingering showers and a potential thunderstorm are noted near
the boundary through the middle of the CWA. There is also plenty
of low clouds and areas of fog along and behind the front.
Otherwise, currently temperatures are generally in the upper 60s
to lower 70s. Meanwhile, amid northerly winds of 5 to 10 mph
behind the front and light/variable winds ahead of it, dewpoints
vary from the low 60s northwest to the lower 70s in the southeast.

The models, and their individual ensemble suites, are in
pretty good agreement aloft through the short term portion of the
forecast. They all depict Kentucky under the influence of a 5h
trough well off to the northeast of the state. This trough
gradually pulls away through the short term portion of the
forecast with some weak impulses passing by in northwest mid level
flow. The regime into the weekend will allow for slowly falling
5h heights as the core of the trough targets the New England
States. The small model spread through Saturday evening supported
using the NBM as the starting point for the forecast grids with
minimal adjustments needed - mainly just to tweak the PoPs for the
diurnal cycle and details from the latest CAMs consensus guidance.

Sensible weather features a cooler day as clouds will dominate
much of it while an airmass change brings drier conditions -
shunting the worst of the heat and oppressive humidity off to the
southeast of the area. Low clouds and early morning valley fog
will only gradually clear out through the morning after dawn -
helping to keep temperatures 10 to 15 degrees below those of
Thursday. Look for a small chance for a shower or thunderstorm -
mainly confined to the southeast portion of the the JKL CWA.
Cooler temperatures will be the rule tonight, too, with more
comfortable readings on tap, but also a good potential for valley
fog - locally dense where the sky stays clear. This fresh air mass
starts to moderate on Saturday with still a small chance for some
convection in the afternoon and evening - but again mainly just
for the southeast parts of the area.

The changes to the NBM starting point were primarily focused on
the diurnal nature to the small PoPs each day with CAMs consensus
guidance included. Temperatures were not changed much with some
extra drying to the dewpoints included for each afternoon.

.LONG TERM...(Saturday night through Thursday)
Issued at 445 AM EDT FRI AUG 1 2025

This morning`s load of the NBM came in reasonable for a pattern
that will feature no strong and dominant pressure systems through
the long term portion of the forecast. This means that the
diurnal cycle will dominate for mainly afternoon showers and
thunderstorms around and no real clear periods of drier air that
could yield decent ridge and valley temperature splits. Therefore
adjustments were kept to a minimum with this extended update.

The previous long term discussion follows:

The period is expected to begin with with upper level ridging in
the western Atlantic centered to the east of Bermuda and
enlongated ridging extending east to west from the Southern Plains to
the Southwest Conus to portions of the eastern Pacific. The
western upper level ridge should initially extend north into
portions of the Rockies while a trough is expected to extend
south west of the west coast of Canada and the Northwest Conus
from an upper level in the Gulf of Alaska vicinity. Meanwhile
broad upper troughing is progged to extend from the Maritimes
into the Northeast Conus to eastern Great Lakes to OH Valley
region on to the Arklatex region. At the surface, a frontal zone
should extend from the Atlantic to southeast US Coast/GA/SC border
vicinity across the Gulf coast states to the Southern Plains and
then north across sections of the High Plains to eastern MT. A sfc
high pressure should be in place centered in the Great Lakes and
extending from sections of the Northeast to the mid MS Valley and
upper MS Valley regions. East of the axis of the upper troughing,
an inverted trough may extend from a sfc wave moving along the
boundary across the Gulf states into sections of the
Appalachians/eastern KY. Also as the period begins, the 00Z LREF
had mean PW of 1 inch or less to the north and northwest of the TN
and VA border counties.

Saturday to Sunday night, the Lower OH Valley and eastern KY
should remain near or to the east of the axis of upper level
troughing that persists between upper level ridging that remains
in place in the western Atlantic centered to the east and
northeast of Bermuda and upper level ridging centered in the
southwest Conus and extending into the Rockies. Although the axis
of troughing in Canada and into the Northeast COnus shifts east
during this timeframe, upper troughing should strengthen a bit
over the Central Conus/MS Valley as the weekend progresses.
Meanwhile, sfc high pressure should settle over the mid Atlantic
states/PA by late Sunday night. As this occurs, return flow of
moisture back to the west and northwest across eastern KY and into
the Lower OH Valley is anticipated with PW per the 00Z LREF mean
increasing a bit Saturday into Saturday night to about 1 inch or
more areawide by Sun morning and to the 1 to 1.4 inch range
through late Sunday into Sunday night. Areas nearer to the VA and
TN border where the moisture gradient is anticipated will have a
better chances for isolated to scattered convection Saturday
afternoon and Saturday evening compared to areas further to the
west along and west of the escarpment and north of the Mtn Pkwy.
Convective chances will spread across the entire area for Sunday
to Sunday evening with the chances likely best in the western half
of the area where more substantial moisture return is
anticipated. The colder airmass will persist with temperatures
remaining a few degrees below normal over the weekend.

For Monday to Wednesday, upper ridging is expected to build across
from the Southwest Conus/NM vicinity and into much of the Plains
while another upper ridge remains in place in the Atlantic. Upper
level troughing the axis of which should extend near the MS River
Valley early on Monday should gradually migrate east to the Great
Lakes to OH Valley to TN Valley to Lower MS Valley vicinity. 00Z
LREF mean PW increases to the 1.3 to 1.6 inch range across
eastern KY by Tuesday to Wednesday. Meanwhile, the sfc frontal
zone initially near the Gulf coast to portions of the Plains is
progged to only gradually lift north and east and remain west of
eastern KY while sfc high pressure remains centered to the
northeast of the area. This pattern will be favorable for times of
clouds as well as the possibility of convection at any point,
though a diurnal peak is expected each afternoon and evening. With
clouds and convection in the area temperatures should average a
little below normal.

For Wednesday night and Thursday, guidance has an upper level low
or trough extending across the OH Valley region into the TN Valley
region though the axis of the trough may reach eastern KY by late
Thursday. Diurnally driven convection should continue to be a
feature and clouds and convection in the area should keep
temperatures near to slightly below normal.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 129 PM EDT FRI AUG 1 2025

Low clouds heights will slowly improve throughout the afternoon,
with generally VFR conditions returning closer toward 20Z as any
diurnal afternoon convection pops up southeast of the TAF terminals.
Look for more low clouds and fog concerns tonight, south of the KSYM
airport. Winds will be mainly light and variable through the period.
Winds just above the surface appear strong enough for most TAF sites
to favor a stratus deck over fog development. At present the
greatest confidence of fog development remains at KSJS.

&&

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

&&

$$

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