915
FXUS63 KLMK 041046
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
646 AM EDT Fri Jul 4 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

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

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

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 210 AM EDT Fri Jul 4 2025

Clear skies and light winds over the region has lead to some very
light fog in the valley areas so far this morning. Expecting this
trend to continue through sunrise.

Ridging aloft will slowly move into the Ohio Valley from the west,
which will increase heights and therefore, temperatures. Expecting
to see high temperatures in the upper 80s to low 90s, and urban
areas will be flirting with the mid 90s. Heat indices will be in the
upper 90s, and with many outdoor activities this afternoon and
evening, it is important to find shade and hydrate. At the surface,
high pressure will keep winds light over the region. Similar to
yesterday with very isolated, brief, light showers popping up in the
afternoon, wouldn`t rule out a similar case in the late afternoon.
Again, this is very low confidence, and with so much dry air at the
surface, would likely not measure rain at the surface.

In the evening, the nocturnal inversion will quickly set up over the
region, given clear skies and calm winds, trapping smoke from local
firework displays under the inversion. This smoke will lead to some
reductions in visibility through the overnight. Low temperatures
will be a bit warmer in the upper 60s and low 70s.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 210 AM EDT Fri Jul 4 2025

Saturday...

Upper ridging will continue to move over the region, which will
increase temperatures into the low to mid 90s for Saturday. High
pressure at the surface will shift off to the east later Saturday,
which will allow winds to begin to veer to the south. Saturday will
likely remain dry.

Sunday - Friday...

High pressure will continue to shift off to the east bringing a
return of southwesterly flow and moisture. Aloft, ridging will
continue to shift off to the east and deamplify. This will keep
temperatures on Sunday in the low to mid 90s. Dew points will
increase slightly, which will bring heat indices flirting with 100F.
At this time, most areas will remain below 100F. Convective temps on
Sunday will be in the low 90s, coupled with some moisture return,
could see some isolated showers develop over the southern half of
the region.

Sunday night through the end of the week, multiple shortwave
disturbances along mostly zonal flow will bring daily chances for
showers and storms. Tuesday a cold front will move south and stall
in the vicinity of the lower Ohio Valley, which will further
increase chances for showers and storms each day. Due to no shear in
the region, not expecting severe storms. However, could see some
strong storms mid week, given increasing CAPE each day. PWATs will
be 2.0-2.1 inches through the week, which could lead to some heavy
rain at times.

&&

.AVIATION /12Z TAFS THROUGH 18Z SATURDAY/...
Issued at 645 AM EDT Fri Jul 4 2025

Mostly VFR conditions expected. Light easterly winds will pick up
by mid morning. A SCT Cu field will develop over the region in the
afternoon. Based on previous years, SDF is likely to drop to at
least MVFR vsby in the planning period due to firework smoke. Patchy
fog will be possible again Saturday morning.

&&

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

&&

$$

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