327
FXUS63 KLMK 241938
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
338 PM EDT Fri Jul 24 2026

.KEY MESSAGES...

* Isolated light rain chance overnight mainly from areas along and
  west of I-165.

* Some spotty shower and storm chances return heading into the
  weekend, and heat and humidity return late weekend into early next
  week. Max afternoon heat indices could be in the triple digits for
  some by early next week.

* A round or two of stronger thunderstorms is possible Monday and/or
  Tuesday, however confidence remains low on the finer details.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 338 PM EDT Fri Jul 24 2026

It is another very nice day across the region, with temps in the
upper 70s and lower 80s. Upper level cloud cover is expected to
continue to increase through this evening as a weak embedded
shortwave rides through the upper level NW flow. This disturbance
will result in some weak radar returns for tonight, though model
soundings show plenty of low level dry air to keep PoPs to an
isolated to scattered chance mainly along and west of I-165
overnight.

Upper ridging will continue to build across the western US for
tomorrow, with general troughing in the eastern US. A weak
stationary boundary extending from the Ozarks down to the Deep South
will be the focus for additional shower and storm activity through
tomorrow, with the best chances mainly to our west and south.
Majority of locations should remain mostly dry tomorrow, though will
still have an isolated to scattered chance through much of the
afternoon. Afternoon destabilization near 1000 J/kg of CAPE, along
with PWATs near 2 inches, will support some pop up thunderstorms.
Shear remains rather weak tomorrow, with flow 20kts or less below
700mb. Most precip activity should diminish by Saturday night as we
lose the daytime instability.

Temps will be a touch warmer tomorrow, with most areas getting into
the low to mid 80s. Dewpoints will also be several degrees higher
than today, with upper 60s and lower 70 sfc dewpoints expected
tomorrow.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 338 PM EDT Fri Jul 24 2026

===== Sunday ======

We remain in deeper NW flow on Sunday as the strong upper ridging
sits over the western US and a trough to the east. Strong daytime
heating, and slightly more humidity, will support strong
destabilization during the day, potentially hitting 3000-4000 J/kg
of SBCAPE. Overall flow through the column remains somewhat weak,
especially below 500mb, but sfc-6km shear parameters over 30kts does
indicate a more favorable profile for organized storms. The biggest
uncertainty continues to be if we get any trigger to initiate
convection. If we are able to achieve convective initiation, some
severe storms may be possible with mainly a wind threat as DCAPEs
over 1000 J/kg may be possible. But if we do not, then the bigger
focus will be on the building heat and humidity. Highs on Sunday are
forecast to hit the lower 90s, with heat indices reaching the upper
90s and close to 100 assuming no afternoon convection.

The GFS and NAM continue to indicate some convective system diving
south through the Ohio Valley Sunday night, but the ECMWF and
Canadian continue to keep us dry. Will be watched closely as we
begin to get into more CAM resolution.

===== Next Week =====

The NW flow pattern holds strong through Monday and Tuesday as well
as the upper ridge remains locked over the western US. We`ll
continue to see increasing heat and humidity during this time, with
temps forecast to reach the lower 90s, and perhaps some mid 90s as
well. Sfc dewpoints returning to the 70s will ultimately yield heat
indices on either side of 100, which could lead to needing some heat
headlines next week if the forecast plays out. The one caveat to
that will be the convective outlook for next week, which the
temperature forecast could be upended if we see any MCS activity.

Addressing the convective potential for next week, a stronger mid-
level shortwave is expected to pivot across the Great Lakes on
Monday, and could be a trigger for MCS activity to develop upstream
of the NW flow. This NW flow would place the Ohio Valley in the path
of any MCS activity, which could include the northern portion of the
forecast area. SPC continues with a 15% risk in the D4 outlook, and
would not be surprised to see a portion of our area get included in
an upcoming outlook for the days ahead. The AI-NWP based convective
hazard guidance is highlighting the lower Great Lakes and Ohio
Valley for severe potential on Monday, and a mid-Atlantic threat on
Tuesday. One limiting factor to the forecast confidence continues to
the inconsistency of global guidance output of notable features, but
we will continue to monitor for the days ahead.

&&

.AVIATION /18Z TAFS THROUGH 00Z SUNDAY/...
Issued at 118 PM EDT Fri Jul 24 2026

VFR weather continues this afternoon and evening, though with
increasing mid and upper level cloud cover. Winds are expected to go
nearly calm overnight, and a weak disturbance could bring -SHRA to
BWG early tomorrow morning. All other terminals are expected to
remain dry, and overall VFR is expected through tomorrow as well.
Winds will swing around from the south tomorrow, but should remain
rather light.

&&

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

&&

$$

SHORT TERM...CJP
LONG TERM...CJP
AVIATION...CJP