852
FXUS63 KLMK 141051
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
651 AM EDT Wed May 14 2025

.KEY MESSAGES...

*  Warmer temperatures and decreasing rain chances are expected
   through Thursday.

*  The potential for waves of strong to severe thunderstorms
   Thursday night through Friday night is increasing.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 357 AM EDT Wed May 14 2025

Upper low centered near Cumberland Gap this morning will move east
across Johnson City, TN and open up as it lifts ENE into the
Delmarva by tonight. Can`t rule out some patchy fog to start the
day, but overall fog formation has been limited by a mid-level
ceiling. Could still see some reduced visibilities in pockets of
clearing, which now seem most likely west of I-65.

Warm and humid air mass remains in place near the sfc, with decent
instability and just enough shear to help keep any convection moving
along. There`s a hint of a warm front that could help focus
convection along a WNW-ESE oriented axis late this afternoon into
the evening, but expect coverage to be scattered at best as upper
ridging starts to win out.

Shortwave ridging aloft is maximized on Thursday, which could be our
warmest day of the year so far. Stout mid-level subsidence will push
H8 temps to 22C, which will serve as a strong cap on any attempts at
convection. Quite a bit of high cloud cover, along with green and
somewhat moist sfc conditions, will be limiting factors on max
temps, but we`ll be solidly in the 80s with a decent chance of
touching 90 in urban Louisville and some of the warmer locations
west of Interstate 65.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Issued at 357 AM EDT Wed May 14 2025

Thursday Night - Friday Night...

As we move into Thursday night, the upper ridge axis slides east of
our area as the potent northern Plains shortwave moves toward the
upper Midwest. A weakened cold front trailing from the MN surface
low will approach our area from the NW. Models show some scattered
convection trying to get going across our northern CWA associated
with this feature. We`ll still have plenty of available instability
with steep mid-level lapse rates, however will likely have at least
some low-level stability with the loss of heating. Therefore, would
expect hail would be the main threat with any stronger storms, and
perhaps an isolated wind damage threat if strong storms are able to
overcome the stable layer.

Assuming convection doesn`t go crazy Thursday night (i.e, cold pool
washing out the airmass), this sets the stage for a bigger severe
concern for later Friday into Friday night. Forecast soundings
continue to show a concerning signal for a strongly unstable airmass
in the presence of plenty of deep layer shear for later Friday into
Friday night. Very steep mid level lapse rates will allow for large
positive area capable of large or very large hail, and damaging
winds. Hodographs also show enough low level looping for tornadic
potential as well. Forecast models suggest that a shortwave embedded
within the parent closed low could rotate into the mid Mississippi
River Valley, triggering upstream convection which would then
progress into our area Friday evening, perhaps into the overnight.
Early indications are that a wind producing, cold pool driven
complex could rake across our region sometime in this timeframe.
Additional concerns would arise with any isolated/supercellular
convection ahead of a cold pool driven complex in the form of very
large hail and tornadic potential. Too early to focus specifically
on a given hazard, but right now, all are in play with damaging wind
being the primary threat.

Saturday - Sunday Night...

The weekend could see a brief drier period as we are expecting the
cold front to be convectively reinforced (cold pool) well to the
south of our CWA. We`ll keep some chances in, especially across our
southern CWA, but much will depend on what happens with late Friday
convection. Upper 70s and low 80s seem reasonable but could vary
depending on the Friday outcome.

Monday - Tuesday...

Upper ridging should start to build over our area by early next week
in response to another strong central CONUS trough. The frontal
boundary that had been stalled to our south will try to lift back
north toward our area as a warm front. Will keep convective chances
in here with temps likely warming back into the low 80s by Tuesday.
Concern is starting to grow for the Tuesday night/Wednesday time
frame for perhaps another round of strong to severe storms.

&&

.AVIATION /12Z TAFS THROUGH 18Z THURSDAY/...
Issued at 651 AM EDT Wed May 14 2025

Light S-SE winds and sct-bkn mid-level clouds have mostly kept the
fog at bay overnight. While the window for fog formation is closing,
still could see a short-lived stratus deck this morning as we start
to mix low-level moisture to the top of a growing boundary layer. If
it were to become a cig, it would be MVFR, but for now will keep it
scattered. Best chance of MVFR stratus cig is at RGA and LEX.

Bases will lift this afternoon as the cu field continues to blossom,
so we`ll have a ceiling but it will be VFR. Winds veer to SSW as
speeds pick up closer to 10 kt. While we do expect isolated to
scattered showers and storms this afternoon, low probabilities and
uncertain timing preclude mention in the TAFs.

Winds will diminish and back to SE this evening with mid-level cigs
overnight.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.

&&

$$

SHORT TERM...RAS
LONG TERM...RAS/BJS
AVIATION...RAS