333
FXUS63 KLMK 160528
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
128 AM EDT Wed Jul 16 2025

...Updated Aviation Discussion...

.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.

&&

.UPDATE...
Issued at 1030 PM EDT Tue Jul 15 2025

Isolated showers and storms continue this evening as we are located
under a 700mb jet combined with an elongated vort wing associated
with the mid-level shortwave. It remains warm and humid at this
time, with temps in the upper 70s and lower 80s still, and dewpoints
in the 70s. This airmass will remain in place, with lows tonight
staying in the 70s. A decaying cluster of storms over western KY are
expected to push into central KY later tonight, but waning
instability and little shear will help continue to erode these
storms. Convective redevelopment, possibly along remnant outflows,
will be possible after 06z tonight. While some rumbles of thunder
will be possible, any storms should be elevated. Heavy rain remains
the main concern tonight, with PWATs exceeding 2.0 inches, and storm
motions not very progressive. Localized flooding issues may arise in
any areas that receive additional rainfall. In western KY, SPC
Mesoanalysis notes a pocket of 2.3" PWATs, so there is plenty of
moisture available for storms to feed off of. Overall forecast
remains in good shape, so no major changes are planned at this time.

&&

.SHORT TERM /THROUGH THURSDAY/...
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 /THURSDAY 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 /06Z TAFS THROUGH 12Z THURSDAY/...
Issued at 128 AM EDT Wed Jul 16 2025

VFR conditions are expected through much of the overnight hours
across the region.  The exception will be at KSDF where a band of
showers/storms to the southwest of the terminal may pass through
between 16/07-09Z.  Current thinking is high enough to include a
tempo group for SDF for the storms.  Elsewhere, will continue a
PROB30 group for overnight convection as mid-level wave rotates
through the Ohio Valley.  Winds will be light overnight out of the
south/southeast.  Expect another repeat performance this afternoon
with scattered convection moving across the region.

&&

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

&&

$$

UPDATE.......CJP
SHORT TERM...BTN
LONG TERM....BTN
AVIATION.....MJ