457
FXUS63 KLMK 170533
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
133 AM EDT Tue Jun 17 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Unsettled weather continues today with afternoon/evening showers
  and thunderstorm chances. The greatest coverage of showers and
  storms should be across portions of western and south central KY,
  where localized swaths of heavy rainfall and flash flooding are
  possible.

* Additional showers and storms are expected Tuesday through
  Thursday, before hot and dry weather arrives next weekend.

&&

.UPDATE...
Issued at 905 PM EDT Mon Jun 16 2025

The atmosphere remains rather juicy this evening as PWAT values
range from nearly 2.10" along our far western CWA to around 1.70" to
our east into the Bluegrass. While some of the earlier showers and
storms are diminishing as they work northeast a second round of
strong showers and thunderstorms is working across western KY and
stretching eastward from Princeton, KY to Bowling Green and then
back southeast towards Tompkinsville. This convection is firing
along a weak boundary and instability gradient. SBCAPE continues to
range from 2000-3000 J/kg with very low mid-level lapse rates being
the main limiting factor. Heavy rain with localized flash flooding
remains he main concern this evening. We continue to have Flood
Advisories and Flash Flood warnings along with the Flood Watch
continuing until 1am EDT.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 328 PM EDT Mon Jun 16 2025

Conditions remain fairly dry as of 2 pm this afternoon, but rain
chances will increase from west to east across the region into the
evening hours. A humid airmass remains in place, with sfc dewpoints
in the upper 60s to mid 70s and PW values between 1.8-2.0 inches.
Forcing has been quite weak thus far today, but we are starting to
see convective initiation to our west over southern IL and western
KY.

A weak upper shortwave and sfc reflection are over the Ozarks this
afternoon, with an effective warm front stretching east across
southern IL and west-central KY. Slightly better low-level
convergence is noted along the front/instability gradient in those
areas, where deep convection has developed (including a robust storm
in Webster County KY).

The mid-level shortwave trough will slowly drift eastward toward the
area this afternoon into tonight. A 25 kt SW LLJ will nose northeast
into the region this evening and overnight, providing a bit more low-
level ascent. The 2+ inch PW plume just to our west will also slide
eastward into our region during this time as well. Expect scattered
convection to develop and increase in coverage across central KY and
southern IN now into the evening hours. While a strong storm is
possible, the main threat will be locally heavy rainfall. While the
environment continues to destabilize, it remains a very moist
airmass with a tall, skinny CAPE profile and poor lapse rates.
Effective deep shear is also marginal at 20-30 kts. But any shower
or thunderstorm will be capable of very efficient rainfall
production, which could lead to localized flooding later this
afternoon and evening. Will leave the current Flood Watch as is,
because that area still looks good for the highest near-term
rainfall potential.

After 03-04Z this evening, convective intensity will diminish due to
waning instability. The arrival of slightly better forcing ahead of
the wave of low pressure will keep scattered rain showers going
overnight. Temperatures will once again fall into the upper 60s to
low 70s for lows.

The mid/upper level shortwave trough swings directly over the region
tomorrow, and we`ll likely start the day with abundant cloud cover
and at least isolated to scattered shower activity. Clouds and
spotty showers will limit sfc heating, but we should still see a
modest boost to shower coverage Tue afternoon. Less available energy
for storms will help limit rainfall rates, but brief heavy rain will
still be possible in a very moist environment. Highs in the low 80s
should be common.

We`ll try to dry out from the west Tuesday night with the mid-level
disturbance passing to the east. The latest model guidance wants to
hold on to just some spotty showers Tuesday night, mainly east of I-
65.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Issued at 328 PM EDT Mon Jun 16 2025

Wednesday through Thursday Night...

Wednesday, a notably stronger wave of low pressure is forecast to
swing northeast over portions of the Midwest - IA, MO, IL, WI.
Strengthening SW flow ahead of this system will continue to pump
warm, moist air into the region. Rain and thunderstorm chances will
increase, especially later in the day. Temperatures appear likely to
warm into the mid/upper 80s during the afternoon hours. The
strongest dynamics/forcing will pass to our north, but stronger
lower to mid-level flow will bring a better chance for strong to
severe storms Wednesday evening into early Thursday. This is
reflected in the latest SPC Day 3 Severe Thunderstorm Outlook, and
in line with recent runs of the CIPS analog-based guidance and the
CSU ML severe progs.

Rain/storm chances linger into Thursday, when a "cold" front will
sweep southeast through the forecast area. Dry weather is expected
Thursday night, though we won`t see significantly cooler air in the
wake of the front. Expect lows in the mid/upper 60s.

Friday through Sunday...

A mid and upper level ridge is forecast to strengthen considerably
over the eastern US this weekend, while a deep trough descends over
the West Coast. A trend toward hot and dry weather is expected for
Kentucky and southern Indiana. Temperatures should warm a little bit
each day, with highs between 84-89 on Friday and 89-95 by Sunday. At
least upper 80s and low 90s are likely over the weekend.

&&

.AVIATION /06Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 132 AM EDT Tue Jun 17 2025

Lingering storms and showers are currently dissipating over east-
central KY, expected to end entirely by 09Z. Ceilings this morning
are expected to be MVFR to possibly IFR as low-level clouds push in
from the northwest and fog develops. Ceilings are expected to lift
and improve around 18Z, with winds around 6kts from the southwest
and gusts of 18kts possible. Showers and isolated thunderstorms are
expected to develop again around 20Z, moving west to east.

&&

.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Flood Watch until 1 AM CDT early this morning for KYZ023-024-
     026-027-061>063-070>074.
IN...None.

&&

$$

UPDATE...BTN
SHORT TERM...EBW
LONG TERM...EBW
AVIATION...JPH