515
FXUS63 KLMK 140139
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
939 PM EDT Sun Jul 13 2025

.KEY MESSAGES...

* Showers and storms could produce a few pockets of heavy rainfall
  overnight, particularly across southern Indiana. Localized
  flooding will be possible where the heaviest rain falls.

* Remaining very warm and humid for most of next week with more
  scattered rain and storm chances each day. Heavy rain, gusty
  winds, and lightning will be the main threats.

&&

.UPDATE...
Issued at 938 PM EDT Sun Jul 13 2025

A weak upper shortwave trof continues to slowly make its way across
the Ohio Valley this evening. The main wave is working into
southeast Indiana as of 01Z, but the southern "tail" of the wave has
hung up near the confluence of the Mississippi and the Ohio. This
elongated trofiness, with plenty of lingering boundaries and an axis
of PWAT exceeding 2.1 inches will remain draped across southern
Indiana and into sections of Kentucky north of I-64 for much of the
overnight.

Collaborated with ILN on the prospect of a Flood Watch, but
confidence in the intensity of rainfall was not high enough. For now
we have bumped POPs up to ~80% for most of the night in southern
Indiana and roughly our northern tier of central Kentucky. Locally
torrential rainfall is possible and we can`t rule out pockets of
flooding overnight.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 344 PM EDT Sun Jul 13 2025

The main focus for the short term will be the potential development
of showers and possible strong storms later this evening and
overnight. While current conditions of temperatures in the mid/upper
80s and dewpoints in the low 70s have allowed for the atmosphere to
destabilize with around 3000 J/kg of SBCAPE, we lack a trigger to get
any widespread activity to fire this afternoon and early evening.
While a few isolated showers and storms are possible late this
afternoon and early evening, our best chance looks to be later this
evening and overnight.

Mid-level shortwave trough axis is orientate SW to NE, stretching
from the Ozarks up into eastern IA and central WI. Ahead of this
feature we have a convective complex over southern IL, with
additional activity stretching into the bootheel of MO and long the
Lower MS Valley. This trough axis will slowly move eastward tonight
and across the Ohio Valley early tomorrow morning. Additional
development is expected as a LLJ increases along the Ohio River
later this evening and overnight. Shear remain weak, but we could
see 20-25kts of 0-6km shear which allow for a little more
organization and MUCAPE of around 1000 J/kg. PWAT values will surge
to above 2.00" making the main threat with these storms gusty
damaging winds with localized flash flooding thanks the very deep
moisture column. Current thinking is that the best chance for these
stronger storms and heavy rainfall is along the Ohio River and
northward from north central KY into IN. This is in line with both
the WPC slight risk for Excessive Rainfall and the SPC Marginal Risk
(1/5) for severe thunderstorms in their day 1 outlooks.

Trough axis works to the east tomorrow as a weak quasi-stationary
sfc boundary sags southward towards the Ohio River to start the work
week. This will continue to keep us in the the very warm and muggy
airmass we`ve been dealing with for the past several days. Placement
of the boundary and afternoon destabilization will once again allow
for scattered showers and thunderstorms to develop late in the day.
Heavy rain, lightning along with gusty winds are the main threat
with the severe threat lower than the last couple of days.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Issued at 344 PM EDT Sun Jul 13 2025

The weather pattern through the rest of the week remains stagnant
with more of the same. We will remain under the influence of weak
ridging aloft along with continued moist and very warm airmass.
Highs each day will be in the low 90s with dewpoints in the low
70s, this will feature diurnally driven shower and thunderstorm
development during the afternoon and evening hours. The threat of
severe storms remains low, gusty winds, lightning and torrential
rainfall remain the main threats.

A few weak mid-level systems will pass to our north over the Great
Lakes Wed/Thu and Thu/Fri. This looks to give us an increased
coverage in precipitation for the end of the week.

&&

.AVIATION /00Z TAFS THROUGH 06Z TUESDAY/...
Issued at 737 PM EDT Sun Jul 13 2025

Timing and impact of convection this evening will be the main
challenge in this TAF set, but this environment does not support
high confidence in details of any forecast.  Expect intermittent
impacts as scattered storms move through, so we`ll start off with
TEMPO groups for MVFR/possibly IFR vis accompanied by TS/CB.
Prevailing VFR initially and through most of the night, but we`ll
get MVFR stratus cigs in most sites by daybreak.  HNB could even
drop into IFR for part of the morning. Low clouds should break out
around midday, with VFR conditions and westerly winds expected in
the afternoon. Convection is possible again late in the day but
confidence is too low to include in the TAF just yet.

&&

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

&&

$$

UPDATE...RAS
SHORT TERM...BTN
LONG TERM...BTN
AVIATION...RAS