679
FXUS63 KJKL 031811 AAB
AFDJKL

AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
211 PM EDT Sun Aug 3 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.

- Torrential downpours leading to isolated instances of high
  water or flash flooding are possible today generally west of
  I-75.

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

&&

.UPDATE...
Issued at 1100 AM EDT SUN AUG 3 2025

A few showers were occurring across the region at issuance time,
with showers to the west of eastern KY at the Cumberland Mesonet
putting down a half of an inch of rain in 15 minutes or about a 2
inch per hour rate. Some of these returns were in parts of the Big
Sandy region where the previous pops were under 15. Overall,
moisture has increased across the region compared to early
yesterday, with values analyzed in the 1.1 to 1.6 inch range,
highest near the TN border and Lake Cumberland region. The
combination of a sfc inverted trough and weak mid level troughing
to the west of the region should continue to support showers and
storms especially in the west and southwest this afternoon and
evening, particularly during peak heating. These may again be
efficient rainers and WPC has a marginal ERO extending into the
Lake Cumberland/west of I-75 area for this potential. Any areas
that pick up slow moving or repeated rounds could experience
instances of high water or flash flooding.

For this update, added isolated to scattered pops a bit further
east and northeast into the Big Sandy region over the next couple
of hours based on radar trends in that area.

UPDATE Issued at 730 AM EDT SUN AUG 3 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.
The PoP chances appeared to be on track this morning and were not
adjusted. Did also wash out most of the fog this morning on
account of the low clouds through much of the southeast. These
minor adjustments have been sent to the NDFD and web servers along
with a freshening of the zones and SAFs.

&&

.SHORT TERM...(Today through Monday)
Issued at 430 AM EDT SUN AUG 3 2025

08Z sfc analysis shows an inverted trough of low pressure nudging
into eastern Kentucky from the south. Earlier, there were a few
showers around associated with this feature but now the diurnal
cycle has settled the convection for the night. Otherwise, a
stratus deck is helping to keep the fog from getting too thick or
expansive this night, though some patches are noted in a few of
the valleys where the clouds are less prevalent. Temperatures vary
from the lower 60s in the north to the lower 70s in the western
Cumberland Valley. Meanwhile, amid light northeast winds,
dewpoints range from the upper 50s north to around 70 degrees near
Lake Cumberland.

The models, and their individual ensemble suites, remain in
good agreement aloft through the short term portion of the
forecast. They all depict some weak troughing over Kentucky today
downstream of a strong ridge centered near northern Mexico. This
allows some mid-level energy to pool over western parts of the
state and slide east into our area later today. Into the start of
the new work week, troughing will become better established over
the Show Me State while 5h ridging builds further above New
Mexico. This will maintain the presence of at least some energy
over Kentucky well into Monday evening amid general troughing
aloft. The small model spread through Monday evening still
supported using the NBM as the starting point for the forecast
grids with minimal adjustments needed - mainly just to tweak the
PoPs by enhancing the diurnal cycle and adding some details from
the latest CAMs consensus guidance.

Sensible weather features another seasonably cool day across
eastern Kentucky with comfortable humidity levels for most. The
exception will likely be found closer to Lake Cumberland where
higher dewpoints will keep some stickiness in the air. The
inverted sfc trough will also allow for a few showers and
thunderstorms developing through the day and peaking in
coverage/intensity during the afternoon and early evening hours.
Diurnally, the activity will mostly settle tonight - drifting
west, along with the lower pressure, during the night. Again some
stratus and valley fog will be around through Monday morning.
Look for a warmer and more normal day to start the work week as
the better rain chances shift west of the area. However, some
small chances will linger for the far southeast - ahead of a
developing sfc low lifting north just to the east of the southern
Appalachian spine into mid week.

The changes to the NBM starting point were primarily focused on
the diurnal nature to the PoPs each day with CAMs consensus
guidance details again included. Temperatures and dewpoints were
not changed much aside from with some extra drying to the
dews each afternoon.

.LONG TERM...(Monday night through Saturday)
Issued at 450 AM EDT SUN AUG 3 2025

This stagnant and rather wet pattern, along with a warming trend,
for the extended portion of the forecast appears to be well
handled by the NBM so no inherent adjustments were needed. This is
especially true for the low temperatures each night showing
little potential for significant terrain differences in this
increasingly humid pattern.

The previous long term discussion follows:

Guidance continues to have the period begin with an upper level
ridge in the western Atlantic and another ridge centered over the
Southwest Conus/Northwest Mexico region with that ridge extending
into sections of the Rockies to High Plains. Meanwhile the OH
Valley region should be in an area of upper level troughing
between the two ridges with the axis of this ridging extending
through the MS Valley. At the surface, the period should begin
with a ridge of sfc high pressure extending from the Great Lakes
to mid Atlantic states with a nearly stationary front extending
from the Atlantic across northern FL and near the Gulf coast and
then into portions of the Southern Plains to High Plains/front
range. A weak shortwave is progged by the guidance to be over the
Lower OH Valley at that point. PW per the 12Z HREF mean, an east
to west moisture gradient should be present across the region as
the period begins with values around 1.1 inches nearer to the WV
border and values near 1.5 inches near Lake Cumberland and overall
not quite as substantial as on Sunday.

From Monday to mid week, ridging centered over the Southern
Rockies/NM vicinity is expected to strengthen a build east and
northeast into the Plains and Central Conus and toward the mid MS
Valley. Meanwhile, ridging centered in the Atlantic is also
expected to strengthen a little and also build into FL and the
eastern Gulf. Upper level troughing should remain in between with
the axis of it moving into the Great Lakes to OH and TN Valleys to
sections of the southeast by late Wed. The 00Z LREF has mean PW
increasing to the 1.4 to 1.6 inch range across eastern KY on Tue
and remaining near those levels into Wednesday and Wednesday
night. The upper troughing will keep the potential for clouds from
time to time as well as convection through the period and there
may be weak sfc troughs present across the OH valley as well. A
general diurnal peak in both clouds and convection is anticipated
each afternoon and evening from Monday to Wednesday. The NBM
continues to be rather consistent with temperatures remaining near
normal. With the pattern and time of year not favoring much in the
way of ridge/valley temperature splits/differences for min T and
guidance in overall good agreement, no notable chances were needed
for NBM guidance into the middle of the week.

For the second half of the week, the axis of upper level
troughing or a broad upper low should continue to remain near or
west of eastern KY with ridging centered in the western Atlantic
persisting along with another upper level ridge remaining from
northwest Mexico to NM into portions of the Central to Southern
Plains. An upper trough should also work across sections of
western Canada and the Northwest Conus to Great Basin and parts
of the Northern Rockies during this period and near the Northern
Plains. The surface boundary near the Gulf Coast and into the
Plains may migrate a bit north and east and toward eastern Ky by
the end of the week while a sfc high pressure ridge remains
centered to the northeast of the Commonwealth. In general the
guidance also has a bit of height rises at 500 mb by the end of
the week with a similar magnitude of PW in place. As during the
start of the work week, the second half of the week should favor
diurnally driven convection with some cloud cover at times as well
even outside of the diurnal peak. A slight upward trend in
temperatures is possible to end next week assuming 500 mb heights
rise. Again with the pattern not favoring much in the way of
ridge/valley temperature splits, little if any changes were
needed as compared to the NBM.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 206 PM EDT SUN AUG 3 2025

A mixture of VFR and MVFR was reported at issuance time with the
MVFR most prevalent in the southwest nearer to KLOZ and KSME.
Some showers were occurring near and to the southwest of KSME and
KLOZ and some IFR or lower is occurring within the heavier
showers and storms at this time. Showers and storms should
generally peak in coverage through 00Z, with reductions to MVFR
and IFR or lower at least briefly within these. Chances are best
for KLOZ and KSME where PROB30 was carried for thunder on station.
Between about 03Z and 13Z, reductions to MVFR or IFR and perhaps
lower than that a few hours either side of 10Z in the southwest
where showers are most probable early in the period. Winds will
average less than 10KT through the period.

&&

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

&&

$$

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