254
FXUS63 KJKL 021100 AAA
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
700 AM EDT Sat Aug 2 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.

- This break from the heat and humidity will continue into the
  start of the new week.

&&

.UPDATE...
Issued at 645 AM EDT SAT AUG 2 2025

Updated the forecast to tamp down the fog as the low clouds have
built in enough, when combined with light northeast winds, to
keep the visibility concerns to a minimum at sunrise. Did also
include the latest obs and trends for the T/Td/Sky grids with this
update. These adjustments have been sent to the NDFD and web
servers along with a freshening of the zones, SAFs, and HWO.

&&

.SHORT TERM...(Today through Sunday)
Issued at 445 AM EDT SAT AUG 2 2025

08Z sfc analysis shows high pressure to the north of Kentucky with
low pressure now off to the southeast. The passage of a cold front
has brought a refreshing air mass to this part of the state - most
evident in the Bluegrass Region with clear skies, lower dewpoints
and northeast winds of around 5 mph overnight. Elsewhere, more
moisture is found at ground level leading to areas of fog -
locally dense in the valleys - along with patches of low clouds.
The clouds and light northeast winds are working to counter the
development and expansion of the fog early this morning but some
dense patches remain. Otherwise, temperatures vary from the
pleasant upper 50s in the northwest to the mid and upper 60s in
the far southeast. Meanwhile, dewpoints range from the lower 50s
northwest to the low to mid 60s in the southeast.

The models, and their individual ensemble suites, are still in
pretty good agreement aloft through the short term portion of the
forecast. They all depict the northeast trough exiting the country
later today but it does leave behind some weakness over the Ohio
Valley and Kentucky with lowering 5h heights noted into midday
Sunday. During this process, plenty of left behind energy will
pool nearby through the rest of the weekend with some impact on
our sensible weather. The relatively small model spread through
Sunday evening again supported using the NBM as the starting point
for the forecast grids with minimal adjustments needed - mainly
just to tweak the PoPs for aspects of the diurnal cycle and
details from the latest CAMs consensus guidance.

Sensible weather features another rather cool and less humid day
as clouds hold in over much of the area. With some support from
aloft, expect the diurnal instability cycle to facilitate the
development of some convection in the southeast parts of eastern
Kentucky later this afternoon. For today, low clouds and early
morning valley fog will clear out through the first part of the
day. Cool temperatures will again be the rule tonight, with
another bout of valley fog anticipated - locally dense where the
sky are mostly clear. The chances of convection will minimize
overnight but never quite go away in the southern parts of the JKL
CWA. These chances increase through the day Sunday - pushed by
the diurnal heating cycle. The best shot at thunderstorms will be
in the afternoon for the Cumberland Valley on Sunday.

The changes to the NBM starting point were primarily focused on
the diurnal nature to the PoPs each day while also incorporating
the details of the CAMs consensus guidance. Temperatures were not
changed much with just some extra drying added to the dewpoints
each afternoon.

.LONG TERM...(Sunday night through Friday)
Issued at 515 AM EDT SAT AUG 2 2025

Again the NBM forecast seemed reasonable through the extended
with only some minor adjustments made to specific spot
temperatures each day amid the overall trend of rising highs
during the week along with daily threats of showers and storms,
mainly highest in the PM.

The previous long term discussion follows:

Guidance still has the period beginning with the region within an
area of broad upper level troughing extending from the Lower OH
Valley to Gulf in between an upper level ridge centered in the
western Atlantic and another upper level ridge centered in
northwest Mexico/the southwest Conus. At the surface, a frontal
zone is expected to extend into northern FL across the northern
Gulf to the Southern Plains and then north into parts of the
Central to Northern Plains while a ridge of sfc high pressure
should extend from the Northeast to the Great Lakes and Upper MS
Valley. Ahead of the axis of the upper trough, a sfc inverted
trough should extend from the Gulf coast into the middle
TN/Cumberland Plateau vicinity and into parts of central to
eastern KY initially as well. Some return moisture is also progged
to work north and northwest into the Commonwealth at that point,
with 00Z LREF mean PW in the 1.1 to 1.5 inch range at that time.

From Sunday to Monday night, the region should remain east of
upper level troughing that becomes established a bit further west
through the MS Valley in between upper level ridging that builds
west from the Atlantic into the Southeast and eastern Gulf and
upper level ridging remaining centered over the southwest
Conus/northwest Mexico area that builds into sections of the
Plains. During that time, PW per the 00Z LREF mean is in the 1.2
to 1.5 inch range so enough moisture will be present for some
convection to begin next week. Guidance generally points toward
greater coverage on Sunday than Monday with a diurnal peak
anticipated each day. Temperatures will remain about 5 degrees
below normal for Monday, before moderating at bit though still a
couple of degrees below normal for Monday. With the trough in
place and clouds at times even at night, as the previous
forecaster noted, no significant ridge/valley temperature
differences are anticipated at night.

Tuesday to Wednesday night, the axis of upper troughing between
ridging centered in the Atlantic and strengthening ridging in the
western Conus to Plains and centered in NM shifts to the Central
Great Lakes to OH and TN Valley to the Southeast. Sfc high
pressure is expected to remain centered to the northeast of
eastern KY at midweek while a warm front gradually shifts to near
the MS Valley to the Southeast extending from low pressure moving
across western to Central Canada in advance of an upper trough
that works into western Canada to the Pacific Northwest.
Convection with a diurnal peak should be a feature each day with
temperatures remaining a few degrees below normal.

Thursday and Friday, troughing is progged to remain from the
central to eastern Great Lakes to the OH valley and Southern
Appalachians to Southeast with the axis of the upper troughing
moving little. A sfc high pressure ridge should remain centered to
the northeast of the region while a frontal zone remains from the
southeast to the mid MS Valley and sags south through northern
sections of the Plains. As at the start of the week, a diurnal
peak in convection is anticipated each day. Current guidance
suggest temperatures moderating back to near normal during this
timeframe as well.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
ISSUED AT 700 AM EDT SAT AUG 2 2025

Low clouds helped to erase much of the fog early this morning with
IFR to MVFR CIGs south of KSYM. All terminals will return to VFR
by mid-morning but increasing PoP chances will exist and a PROB30
for KSJS and KJKL may be needed after 18Z. Again late tonight
areas of valley fog may affect some of the TAF sites. Winds will
be light and variable through midday before picking up from the
northeast at 5 to 10 kts.

&&

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

&&

$$

UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...JP/GREIF
AVIATION...GREIF