451
FXUS63 KLMK 032354
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
754 PM EDT Thu Jul 3 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Very warm temperatures with highs in the 90s for most, but
  reasonable humidity levels through Independence Day.

* Higher humidity returns this weekend, with rain and thunderstorm
  chances increasing Sunday into next week.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 320 PM EDT Thu Jul 3 2025

Sfc high pressure over the Ozarks is maintaining a light northerly
breeze across the Ohio Valley, which is keeping the humidity
reasonable with dewpoints in the lower 60s. NW flow aloft still has
some weak cyclonic curvature, so the Cu field is fairly extensive.
Even with that, building heights have helped to push temps to around
90 degrees.

Light winds and clearing skies tonight will favor radiational
cooling, so expect at least patchy fog toward Friday morning,
especially in valleys and other sheltered areas. For Friday the sfc
high will consolidate over western New York, setting up a light east
wind across the Ohio Valley. Heights will be rising, so temps look
to run 2-3 degrees above today, with lower to mid 90s for most.
Dewpoints remaining in the lower/mid 60s will keep the heat index
out of triple digits.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 320 PM EDT Thu Jul 3 2025

Humidity starts to ramp up this weekend as the sfc ridging slips
east of the mid-Atlantic coast. Temps will easily reach the
lower/mid 90s but dewpoints will rise slowly, not reaching 70 until
fairly late Sunday afternoon as S/SW flow deepens.  Not much concern
yet about heat index values reaching advisory thresholds. but if
dewpoints recover more quickly than advertised we could start to see
the heat index reach 100+.

Shower and thunderstorm chances also start to ramp up on Sunday,
with scattered coverage expected for much of next week. Westerlies
are fairly weak this far south, so no real shear to organize storms.
However there is sufficient instability that if storms do develop,
they could be strong with pulse severe hazards on the table.

&&

.AVIATION /00Z TAFS THROUGH 06Z SATURDAY/...
Issued at 752 PM EDT Thu Jul 3 2025

Mostly VFR conditions expected. The afternoon cumulus is
dissipating, leaving mainly clear skies overnight. HNB may see vsby
drop to low-end MVFR or possibly brief IFR between 08-12Z Fri. Very
light/variable to calm winds tonight, with a light easterly wind
developing Friday. Based on previous years, SDF is likely to drop to
at least MVFR vsby in the planning period due to firework smoke.

&&

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

&&

$$

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