799
FXUS63 KLMK 171936
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
336 PM EDT Tue Jun 17 2025

.KEY MESSAGES...

* Showers and thunderstorms through this evening could produce
  localized heavy rainfall and flooding.

* Strong to severe storms are possible on Wednesday, mainly during
  the evening. All severe weather hazards are on the table, but
  damaging winds will be the primary threat.

* Hot and dry weather arrives Friday and will continue well into
  next week.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 334 PM EDT Tue Jun 17 2025

Scattered showers are developing in a warm and humid air mass this
afternoon, with some embedded thunder and lightning but no real
organization due to a lack of shear. Storm intensity is limited due
to weak lapse rates, but PWATs are near 2 inches so heavy rainfall
and flooding remain in play. Expect disorganized convection to
continue for the rest of the afternoon and into this evening, with
enough coverage to bring at least measureable precip to the majority
of the area.

Showers and storms die out mid to late evening, with some stratus
build-down potential overnight. With clouds and oppressive humidity
limiting diurnal temp ranges, lows will run around 70 with the
exception of urban Louisville, which could stay in the mid 70s if it
doesn`t rain. A better warm advection regime Wednesday morning will
kick winds up out of the SW and spark a new round of showers and
storms.  Will keep coverage scattered in this time frame, with
minimal impacts.

The most impactful weather is expected Wednesday night ahead of the
main cold front. Convection will break out over southern Missouri,
and then it`s a race between approaching storms and the setting sun
to determine the level of impacts here in the Ohio Valley. Stronger
wind fields will provide more storm organization, likely allowing
for a QLCS that will push toward central Kentucky and southern
Indiana as we get to around sunset. The overall trend will be for
storms to weaken once heating is lost, but the question is how far
east the line advances before that happens. Main severe wx hazard
will be damaging winds, but large hail or even a tornado can`t be
ruled out. Best chances are NW of a line from roughly Bowling
Green to Lexington. Confidence remains low due to uncertainty
regarding available instability.


Later in the night, we could still see another line of convection
move through the area. Confidence in that batch of storms is even
lower as much of the atmosphere is likely to be worked over. The
more likely scenario could involve storms training along an
east- west boundary, which would lay out across southern
Kentucky. If this pans out, weather could remain active
overnight into Thursday morning, with an emerging flash flood
threat.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 334 PM EDT Tue Jun 17 2025

By Thursday morning, the cold front, embedded in an upper trough,
that brought storms on Wednesday night is expected to be somewhere
in the Lower Ohio Valley as it pushes off to the east. Timing is
slightly different on exactly when the front and wind shift will
occur. This is less significant as all the severe potential is
expected to be ahead of the front, east of the CWA.

Behind the front, upper ridging and surface high pressure moving
east of the Ozarks will usher in lower precipitable water values.
Initially values will fall below 1.5" behind the front, but they keep
falling to around an inch later in the day. This will be noticed at
the surface as dew points fall from the low 70s to the mid 60s over
much of the CWA, but values to the southwest (Bowling Green area)
will likely remain in the upper 60s. This drying trend will help to
clear skies from the northwest to southeast during the afternoon and
evening hours. Cold air advection behind the front will help drop
highs from the mid to upper 80s on Wednesday to the low to mid 80s
on thursday.

Early Friday, upper ridging pushes the surface high east of southern
Indiana and central Kentucky, returning warm air advection to the
Lower Ohio Valley. Highs climb into the mid to upper 80s Friday
before the low to mid 90s by the weekend. The upper ridge and
surface high stall over the region, keeping mostly sunny skies and
warm temperatures in the area into early next week, but as the high
over the Southeast usher more moisture northward, chances for
afternoon/evening convection will begin increasing early next week.

&&

.AVIATION /18Z TAFS THROUGH 00Z THURSDAY/...
Issued at 139 PM EDT Tue Jun 17 2025

Mainly MVFR cigs in place, finally lifting above 2000 feet at the
moment. A smattering of showers across the area will increase in
coverage just enough to warrant a PROB30 mention later this
afternoon, with vis most likely dropping into MVFR or briefly IFR.
These impacts should be brief/intermittent.

Overnight look for light south winds and cigs building down to less
than 2000 feet. By Wednesday morning we lose the low clouds, with
mainly mid-level ceilings as a result of debris from upstream MCS.
SW winds will increase late Wed morning ahead of the incoming cold
front, with prevailing gusts pushing 20 kt.

&&

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

&&

$$

SHORT TERM...RAS
LONG TERM...KDW
AVIATION...RAS