139
FXUS63 KLMK 151919
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
319 PM EDT Tue Jul 15 2025

.KEY MESSAGES...

* Very warm and humid conditions are expected this week with
  scattered afternoon/evening thunderstorms.  Torrential rainfall,
  gusty winds, and lightning will be the main threats with this
  activity.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 318 PM EDT Tue Jul 15 2025

Remnant MCV is working over the Ohio Valley this afternoon and as it
interacts with the moist unstable environment we will see bands and
clusters of showers/thunderstorms that produce torrential rainfall.
PWAT values are around 2.00", SBCAPE 2500-3000 J/kg with a storm
motion of 15-20 mph this afternoon with no shear and poor mid-level
lapse rates rates, the main impacts remain the heavy rainfall that
could lead to very localized flooding and even ponding on area
roadways this afternoon into the early evening. Storms will have
frequent lightning and could get some gusty winds.

Some lingering convection towards eastern and southern KY is
possible  as we go into the evening but overall we may see a brief
lull in activity before a a weak mid-level wave over the Ozarks this
afternoon works across the area along the Ohio River and southern IN
later tonight into tomorrow morning. Could see some enhanced lifting
thanks to a 30kt LLJ and it looks to arrive late tonight and through
the early morning hours with additional rain and thunderstorms with
more heavy rainfall, as PWAT values remain around 2 inches, frequent
lightning and a localized flooding concern as these showers/storms
could work over the same places that saw the heavy rain this
afternoon.

Mid-level wave works eastward during the morning hours of tomorrow
with lingering showers/storms across our far eastern CWA at the
start of the day. It will be generally more of the same with the
muggy and very warm air in place but with continued weak ridging
over the area tomorrow we may see more isolated than scattered
convection in the afternoon and evening with highs in the upper
80s/low 90s and dewpoints in the low/mid 70s.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 318 PM EDT Tue Jul 15 2025

Shortwave trough ejecting out of the Pacific Northwest today will
meet up with a developing sfc low across the Plains tomorrow and
work across the Great Lakes Wednesday night into Thursday flattening
out the ridge over the Ohio Valley and southeast US. An associated
cold front will drop southeast out of Upper Midwest Thursday into
Thursday night before stall along to just north of the Ohio River
for the end of the week into the start of the weekend. We will
remain in the very warm and juicy airmass with mainly diurnally
driven convection each day as highs will be in the upper 80s/low 90s
nearly every day with the exception of Thursday where highs could be
in the low/mid 90s. As has been the trend the last several days,
while we have convective chances each and every day, we continue to
lack shear which keeps the overall severe threat low. Frequent
lightning, gusty winds and heavy rainfall will continue to be the
main impacts from any showers/storms that form over the next several
days. Localized flooding with repetitive rounds of showers/storms
will be the biggest overall impact.

&&

.AVIATION /18Z TAFS THROUGH 00Z THURSDAY/...
Issued at 148 PM EDT Tue Jul 15 2025

The remnants of a MCV is working across the Ohio Valley this
afternoon and is producing clusters of showers and thunderstorms that
is producing heavy rainfall with them. These will likely be around
most of the afternoon as this wave slowly works to the east-
northeast providing enough lift for ongoing convection. The
challenge is just timing and overall coverage. Kept PROB30 in for
practically all locations this afternoon until around sunset. Other
than that the flight categories should remain VFR outside of these
showers/storms.

Bit of a break into the early evening but a second convective
cluster associated with energy currently over northern AR and
southern MO will start to work into the Ohio Valley overnight into
the pre-dawn hours. Likely starting after 06z. This doesn`t look
severe but more of the same with heavy rainfall, occasional gusty
winds and lightning. There isn`t strong agreement on timing or even
strength but added PROB30s overnight.

&&

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

&&

$$

SHORT TERM...BTN
LONG TERM...BTN
AVIATION...BTN