878
FXUS63 KLMK 301051
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
651 AM EDT Thu Jul 30 2026

...Updated Aviation Discussion...

.KEY MESSAGES...

* Dry and less humid conditions continue through Friday.

* Showers and thunderstorms will return late Friday night and
  Saturday. Some strong to severe storms are possible on Saturday,
  along with heavy rainfall and possible flooding issues in spots.

* More scattered shower/storm activity possible early next week,
  mainly in the afternoon and evening hours.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 316 AM EDT Thu Jul 30 2026

Sfc high pressure is positioned over northern IL early this morning,
with very light NE/calm winds over southern IN and central KY. Skies
are mostly clear, with just a few lower clouds drifting over the
region. Temperatures are dropping into the 60s, which will make for
a rather pleasant morning. Temperatures are still expected to bottom
out in the upper 50s to lower 60s in most places early this morning.

Dry NE flow continues today as high pressure slowly settles
southeast over the OH Valley. Expect a mostly sunny day, with just
FEW-SCT afternoon cumulus. The latest model guidance also suggests
we`ll have much less smoke present aloft. Afternoon temperatures
will rebound into the low to mid 80s.

Sfc high pressure lingers over the region tonight before shifting
east of the area on Friday. An upper level ridge axis shifts
southeast over the area ahead of an amplifying upper level shortwave
trough over the Upper Midwest. After riding over the top of the
upper ridge, this mid/upper level shortwave disturbance will dive
southeast within the NW flow regime. A sfc low tied to the upper
level wave is forecast to develop southeast across Iowa on Friday.
Numerous showers and thunderstorms are forecast to evolve across
Iowa, Missouri, and Illinois tonight into Friday ahead of the wave
of low pressure and attendant cold front.

Locally, we will just see some increasing high clouds spread in from
the northwest tonight. Temperatures will gradually fall into the low
to mid 60s early Friday morning. It does still appear that much of
Friday (the daytime) will remain dry, though we could see scattered
convection work into SW Indiana by late evening. Developing
southerly flow and warm advection ahead of the approaching wave will
help boost temps into the mid and upper 80s Friday afternoon.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 316 AM EDT Thu Jul 30 2026

The mid/upper level trough rotates southeast over Iowa and Illinois
Friday night into Saturday, with the low closing off in the mid-
levels. The sfc low should occlude over Illinois by Saturday
morning. A developing 25-30 kt SW LLJ will enhance low-level WAA and
moisture transport ahead of the low late Friday night, and
especially into Saturday morning. A round of showers and elevated
storms appears likely early Saturday. The severe weather risk will
be very low at this time.

Numerous rain showers are expected on Saturday, and it`s not clear
how much of a window we`ll have to destabilize. A 30 kt SW LLJ will
continue to pump warm, moist low-level air into the region Saturday
afternoon as the sfc low spins over southern IL. Sfc dewpoints are
forecast to rise into the low to mid 70s, and pockets of moderate
destabilization (MLCAPE 1000-1500 J/kg) are certainly possible.

Effective deep shear of 25-30 kts will be marginal for organized
convection, though the enhanced lower level wind fields should at
least boost the potential for isolated strong wind gusts. Backed sfc
winds out of the S/SSE just ahead of the low does enhanced low-level
curvature on forecast hodographs. Forecast low-level shear and SRH
are still fairly modest, however.

Storm mode is currently expected to be a mix of loosely organized
multicells, with embedded supercellular structure. Overall, it
appears to be a conditional risk for severe weather on Saturday.
Forecast confidence in severe storms is low-medium. Isolated
damaging winds are likely the primary threat, with a lower risk for
a tornado or two.

LREF mean PW values are forecast to increase into the 1.8-2.0 inch
range on Saturday. The moist environment will be supportive of heavy
rainfall rates of 1-2 inches/hr. Locally heavy rainfall could result
in flash flooding. Average rainfall amounts of 1-2 inches look
possible, though locally higher totals will be possible due to
convection.

Stacked low pressure drifts overhead on Sunday, likely allowing
lighter showery weather to continue. The weakening cutoff mid-level
low may meander over the TN Valley through midweek, while the sfc
boundary stalls and slowly washes out over the eastern CONUS. A
chance for scattered showers and storms will linger Monday through
Wednesday, especially during the afternoon and evening hours.

&&

.AVIATION /12Z TAFS THROUGH 18Z FRIDAY/...
Issued at 650 AM EDT Thu Jul 30 2026

VFR conditions likely through the period. Very brief MVFR conditions
due to fog are possible at HNB and RGA through 12-13Z this morning.
NE winds will increase to 5-7 kts this afternoon. Expect FEW-SCT
cumulus today near 5 kft. SCT high clouds will spread in from the
northwest tonight.

&&

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

&&

$$

SHORT TERM...EBW
LONG TERM...EBW
AVIATION...EBW