545
FXUS63 KLMK 052347
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
747 PM EDT Thu Jun 5 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Strong storms possible this afternoon and evening.

* Strong to severe storms possible Friday and Saturday in the
  afternoon.

* 1.5 to 2 inches of rainfall is expected through the weekend.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 314 PM EDT Thu Jun 5 2025

A surface front is located just of the northwest of the region and
will slowly sink south into southern Indiana this evening. A weak
25kt LLJ is helping to pump Gulf moisture into the region along
southwesterly flow. The moisture, surface front, and daytime
heating, will allow for some isolated to scattered showers and
storms to develop this afternoon through the evening. Shear aloft is
quite weak, so we are expecting instability driven unorganized
development. Could see some gusty winds, small hail, and locally
heavy rainfall. Areas in the eastern portion of the region will
likely remain dry since showers and storms will dissipate as they
move east. Starting to see some better Cu development at this 18Z
hour, which increases confidence in at least isolated showers and
storms.

In the overnight hours, the upper pattern will begin to flatten out
leading to more zonal flow aloft. A few very weak vort lobes will
drift over the region along this upper flow, which will bring a
chance for very isolated showers. Most, if not all, areas will
remain dry overnight. Scattered to broken skies overnight will help
prevent efficient radiational cooling, keeping low temperatures on
the warmer side in the upper 60s and low 70s.

On Friday, the surface front will be draped in the vicinity of the
Ohio River. Continued moisture pumping into the region, coupled with
a wave moving along zonal flow aloft, will allow for strong to
severe storms to move through Friday afternoon and into the evening.
This wave will be more robust than the Thursday (today) storms. This
wave will develop over the central Plains and move into the lower
Ohio Valley as an MCS. Shear continues to look weak, therefore these
storms will be instability driven. In the afternoon, forecast
soundings show 2000-2300 J/kg of SBCAPE. Could see some gusty to
damaging winds, hail, and locally heavy rainfall.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 314 PM EDT Thu Jun 5 2025

Friday Night - Sunday...

Zonal flow will continue to the be main feature aloft over the
region through most of the weekend. Another round of vorticity along
a weak wave will move through on Saturday afternoon bringing showers
and storms. This wave is not as robust as Friday, however gusty to
damaging winds, hail, and locally heavy rainfall will be possible.

The boundary that will be parked over the Ohio River for several
days will finally push southeast on Sunday bringing yet another wave
of showers and storms.

Broken to overcast skies will remain over the area which will help
to keep temperatures in the upper 70s and low 80s for highs and
upper 60s for lows.


Sunday Night - Mid Next Week...

A closed upper low will sink south from central Canada on Monday.
This feature will swing through the Ohio Valley and Great Lakes
through mid week. This will send a cold front through the lower Ohio
Valley Monday into Tuesday. The current forecast places the region
under the right entrance region of an upper jet, a neutrally tilted
shortwave, and a weak LLJ. Along the cold front, could be another
opportunity for storms (potentially strong storms) to move through.

Behind the front, high pressure will build in behind the front
bringing slightly lower dew points and slightly cooler than
normal temperatures back to the region.

QPF through Monday looks to be 1.5 - 2.0 inches.

&&

.AVIATION /00Z TAFS THROUGH 06Z SATURDAY/...
Issued at 746 PM EDT Thu Jun 5 2025

Per area radars, the bulk of the shower/storm activity passed by to
our north. HNB saw a few showers and could see a few light rain
showers at the start of the forecast period but most, if not all, of
the TAF sites should remain mostly dry, VFR and light winds. The one
area of concern between now and 12z tomorrow morning is the
development of low stratus for HNB and possibly SDF/LEX. For now,
decided to keep the IFR/MVFR around HNB while holding on to VFR for
the rest of our terminal sites.

As a qausi-stationary boundary continues to get closer to the area,
more clouds and the chances of showers/storms increase especially in
the afternoon/evening. A system coming out of the plains overnight
and tomorrow morning will start to work into the Ohio Vally late in
the day tomorrow. Strong showers/storms, some possibly severe with
strong gusty winds will be possible. Confidence is low on timing and
just overall on the how storms will develop later tomorrow
afternoon. Winds will become more westerly during the day.

&&

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

&&

$$

SHORT TERM...SRW
LONG TERM...SRW
AVIATION...BTN