361
FXUS63 KLMK 311952
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
352 PM EDT Thu Jul 31 2025

.KEY MESSAGES...

* Scattered showers and thunderstorms will continue this afternoon
  before subsiding this evening.

* Cooler and less humid air returns for Friday into the weekend.

* Chances for isolated to scattered showers and storms return
  Sunday, continuing into early-to-mid next week.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 352 PM EDT Thu Jul 31 2025

This afternoon, a broken line of showers and thunderstorms has
developed across central KY, with thunderstorms producing gusty
winds, torrential rainfall, and copious amounts of lightning. These
showers and storms have developed along a cold front which is
pushing through the region, feeding off of 2000-3000 J/kg MLCAPE
along and south of the front. South of the front, temperatures have
warmed into the upper 80s and lower 90s across south central KY,
with steamy dewpoints resulting in heat indices ranging from 100-
105. The cooler and drier air is still up over central IN at this
hour, though it will filter into the area as we head through the
evening and overnight hours. Showers and storms will continue to
push off to the south and east this afternoon, gradually winding
down by around sunset.

Tonight, high pressure strengthening over the upper Midwest will
increase northerly flow into the lower Ohio Valley, with a
persistent 5-15 mph breeze expected overnight. This breeze will help
to bring lower dewpoints into the region, clearing out the humid air
mass which has remained in place for the past week or so. The low
stratus layer which is currently located to the north of the region
is expected to move overhead tonight, with mostly cloudy to overcast
skies expected for much of tonight. Within this stratus layer, it is
possible that some patchy sprinkles or light rain could develop,
though most should remain dry. Temperatures should fall into the 60s
in most areas by sunrise Friday, though areas across south central
KY will be close to 70.

Tomorrow, high pressure will continue to settle into the Midwest,
with north-northeasterly low-level flow continuing into the Ohio and
Tennessee valleys. This cool N/NE flow, in addition to lingering
stratus, will suppress temperatures, with highs only expected to
reach the upper 70s and lower 80s across southern IN and central KY.
While a stray shower is possible along and south of the Parkways,
most areas will remain dry as mid-level subsidence moves into the
region behind the front. By tomorrow afternoon, HRRR smoke progs
show mid- and upper-level smoke from wildfires over the
intermountain West and western Canada moving into the region. Health
impacts are not expected at this time, as near-sfc smoke values are
expected to remain relatively low.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 352 PM EDT Thu Jul 31 2025

Over the weekend, a fairly static synoptic pattern is expected
across North America as upper-level ridging gradually retreats
toward Baja California while troughing continues over the Canadian
Maritimes. Surface high pressure will remain centered over the
Midwest and Great Lakes region, with NE low-level flow keeping
temperatures and dewpoints suppressed. Seasonably cool temperatures
are expected Saturday and Sunday morning, with lows expected to fall
into the upper 50s and low-to-mid 60s. Highs Saturday and Sunday
will also be below normal, ranging from the upper 70s to the mid
80s. By Sunday, the center of sfc high pressure will shift east of
the Appalachians, setting up a wedge pattern for the Carolinas up
into the mid-Atlantic. This pattern will start to bring moisture
back into the area via east-southeasterly low-level flow,
particularly across south central KY. With moisture expected to
increase, chances for afternoon showers and storms will also return
on Sunday, with the best chances across south central KY.

Over the first half of next week, medium-range guidance shows a weak
upper low drifting from the upper Midwest toward the Ohio Valley as
upper ridging strengthens over the southwestern US. While the
pattern will be somewhat supportive for increased shower and storm
chances, the air mass is not expected to be particularly moist,
especially for early August (PW 1.4-1.6"). As a result, the current
expectation would be for isolated to scattered afternoon and evening
showers and storms. No rapid warm up is expected through the first
half of next week, though temperatures should gradually approach
climatological normals, with highs in the mid-80s and lows in the
60s.

&&

.AVIATION /18Z TAFS THROUGH 00Z SATURDAY/...
Issued at 145 PM EDT Thu Jul 31 2025

Scattered showers and thunderstorms have developed along a cold
front which is pushing to the south across the region at this hour.
Through the afternoon and evening hours, the best chances for
SHRA/TSRA should be at BWG, LEX, and RGA, which is still south of
the main line of storms. However, isolated storms could still pose a
threat to SDF and HNB through sunset.

As the front pushes south of the area this evening, winds will swing
around to the north and remain breezy overnight, particularly at
SDF, LEX, and HNB. Ceilings are expected to fall to MVFR levels for
at least a few hours tonight, with conditions gradually improving
from north to south on Friday as drier air moves into the region.

Forecast confidence in TSRA/SHRA is low-medium, confidence in
ceilings is medium, and confidence in winds is medium-high.

&&

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

&&

$$

SHORT TERM...CSG
LONG TERM...CSG
AVIATION...CSG