593
FXUS63 KJKL 042311
AFDJKL

AREA FORECAST DISCUSSION
National Weather Service Jackson KY
711 PM EDT Thu Sep 4 2025

.KEY MESSAGES...

- Multiple rounds of showers and thunderstorms are likely to
  impact the area between now and Saturday, with the highest
  probabilities immediately ahead of an approaching cold front
  Friday evening/night.

- A few of the storms Friday evening may be strong to severe;
  damaging wind gusts are the primary concern but can`t rule out a
  spin-up tornado.

- Widespread rainfall totals between 1.0 to 1.75 inches are
  possible through late Saturday night, but locally higher totals
  are possible wherever stronger convection occurs.

- Below normal temperatures and drier weather will return this
  weekend.

&&

.UPDATE...
Issued at 710 PM EDT THU SEP 4 2025

Showers and thunderstorms will continue moving generally to the
east across the far southern and southeastern parts of the
forecast area, but also cannot rule out stray development to the
north for the next few hours. Adjusted PoPs generally downward a
bit with the early evening update.

&&

.SHORT TERM...(This evening through Friday night)
Issued at 427 PM EDT THU SEP 4 2025

Much-needed rain fell across eastern Kentucky today, though the
main area of widespread rainfall has since shifted southeast of
the area, leaving behind variable cloud cover. Radar estimates
show a clear north-to-south gradient in what fell, with 0.2 to
0.75 inches north of the Mountain Parkway, increasing to 0.5 to
1.5 inches for most locations further south. Temperatures remain
cool in the mid-60s to around 70 degrees, except in the mid 70s
near Lake Cumberland. The synoptic setup features a stalling cold
front to our northwest, from roughly Cynthiana to near Bowling
Green, its advance halted by weakening upper-level forcing. This
front extends southward from a strong, nearly vertically stacked
low north of Lake Superior. Further upstream, a potent shortwave
trough accompanied by another strong cold front is dropping out of
Canada into the Dakotas and will become the main driver of our
weather on Friday/Friday Night.

Through the remainder of the daylight hours, scattered showers
and a few thunderstorms can be expected to develop as the front
drifts closer, diminishing from northwest to southeast this
evening with the loss of daytime heating. Overnight, a
strengthening low-level southwesterly flow will bring renewed
warmth and moisture into the region. While guidance is uncertain
on the extent of low clouds, the strength of this flow (10 to 20
kts just off the surface) favors the development of a low stratus
deck over widespread fog. This sets the stage for Friday, when
this warm air advection will translate to the surface. At 850 mb,
temperatures climbing into the 16-18C range will support
widespread highs in the mid to upper 80s, while PWATs climb to
between 1.5 and 1.8 inches. A weak cap should keep a lid on this
increasingly unstable airmass for most of the day, allowing MLCAPE
to build to 1,500-3,000 J/kg. The trigger for releasing this
instability will arrive late in the afternoon, as subsiding
heights ahead of the strong cold front cause the cap to weaken.
Sufficient shear will favor initial storm development as discrete
supercells capable of producing large hail and damaging winds. A
further notable concern is the potential for this highly unstable
airmass to coincide with a strengthening low-level jet (exceeding
30 knots at 850 mb) Friday evening. If this jet develops before
convection becomes widespread, the resulting enlarged and looping
hodographs create a favorable environment for tornadic supercells,
with the greatest concern currently north of the Hal Rogers
Parkway/KY-80 corridor. Later in the evening, storms are expected
to become widespread, producing torrential downpours at times. A
general 0.5 to 1.5 inches of rain is anticipated, though localized
totals over 2 inches are possible.

In sensible terms, lingering showers and thunderstorms this
evening will wane after sunset, followed by a mild night with a
mix of partial clearing and areas of low stratus or fog. A rogue
shower cannot be ruled out as well, but that would be very
isolated. Low temperatures will be in the mid-50s to around 60.
For Friday, mostly sunny skies will help temperatures climb into
the mid to upper 80s. Showers and thunderstorms are expected to
develop over western counties by late afternoon, increasing in
coverage and intensity through the evening and overnight. Some of
these initial storms could be severe, with damaging winds, large
hail, and isolated tornadoes all possible. It will be a very wet
night with low temperatures falling back into the mid-50s to lower
60s.

.LONG TERM...(Saturday through Thursday)
Issued at 217 PM EDT THU SEP 4 2025

Lingering showers and thunderstorms will continue to impact
eastern Kentucky on Saturday as a slow-moving cold front
approaches the region. Eventual FROPA is slated for Saturday
afternoon, with high pressure building behind the boundary. Much
cooler temperatures will be in place on Sunday with afternoon
highs in the low to mid 70s.

A slight warming trend will be evident next week as an upper level
ridge forms over the Central Plains. Easterly surface flow will
advect slightly warmer temperatures with highs climbing to the
upper 70s and lower 80s by Tuesday. Dry and warm conditions will
persist through the remainder of the week as high pressure
continues.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 654 PM EDT THU SEP 4 2025

Any lingering convection should remain well south and east of the
terminals this evening, so all mention of precipitation this
evening has been removed with the 00z TAF package. The cold front
stalls near the escarpment tonight while increasing low-level,
moist warm advection may support low stratus in addition to areas
of fog. Light and variable winds will generally prevail but gusty
and erratic winds could accompany convection.

PROB30 groups have been added for the end of the TAF period for
showers and thunderstorms ahead of the second and final cold
front which will cross the area Friday night.

&&

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

&&

$$

UPDATE...CMC
SHORT TERM...GEERTSON
LONG TERM...SCHLESSIGER
AVIATION...CMC