610
FXUS63 KLMK 131104
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
704 AM EDT Wed Aug 13 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Warm and humid today, with isolated to scattered showers and
  thunderstorms. The risk for severe weather is low, though some
  storms could produce locally heavy downpours and frequent
  lightning.

* Hot and humid this weekend with highs in the low to mid 90s.
  Triple digit heat index values possible at times.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 306 AM EDT Wed Aug 13 2025

Weak mid-level shortwave troughing is noted over the Lower Ohio
Valley this morning, with a deeper northern stream wave swinging
over Ontario and the Great Lakes. At the surface, a cold front is
draped NE to SW through Lower MI and northern IL/MO. We still have a
couple isolated thunderstorm drifting east across south-central KY
early this morning, where PW values exceed 2.0 inches. Subtle low-
level convergence enhanced by an outflow boundary, as well as weak
ascent provided by the approaching mid-level wave, may be enough to
sustain isolated convection south of the Bluegrass Parkway over the
next few hours. Otherwise, most will stay dry. Temperatures are
hovering in the lower 70s under partly cloudy skies.

Lower clouds are forecast to expand in coverage through the early to
mid-morning hours, trending the sky cover toward mostly cloudy in
many areas to start the day. Skies will become partly sunny during
the afternoon, though sky cover may be somewhat variable depending
on convection.

Today, weak mid-level troughing will remain in place as the cold
front to our northwest sinks to the Ohio River by this evening.
Isolated to scattered rain/storm chances will increase during the
afternoon and evening hours with diurnal warming providing a boost
to coverage and intensity. Coverage should be a bit higher across
portions of central and southern KY, where moisture and instability
will be relatively higher (compared to southern IN). Weak deep-layer
shear (15 kts or so) will continue to limit convective organization
and the ability to sustain an updraft. The severe weather risk is
low, though any storm could produce brief heavy rainfall and
lightning. Highs today will be in the upper 80s/near 90.

Tonight, rain chances gradually taper off as the low levels
stabilize. Look for partly cloudy skies with the possibility of some
fog. Lows will be in the upper 60s to lower 70s.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 306 AM EDT Wed Aug 13 2025

A weak cold front will continue to sink south through the forecast
area on Thursday. Upper level support looks quite weak, and drier
mid-level air is forecast to spill into the region from the
northwest. Thus, rain chances look fairly spotty and confined to
central and eastern KY. Most will stay dry, with afternoon highs
once again in the upper 80s to near 90.

A strong mid-level ridge is forecast to build over the Mississippi
Valley and Lower Ohio Valley, which is likely to bring a stretch of
hot and dry weather Friday into early next week. Saturday through
Monday looks like the hottest period, with afternoon highs in the
low to mid 90s. Afternoon heat index values will flirt with 100 each
day. Strong mid and upper level ridging eventually shifts to the
western United States by the middle of next week, which allows for
NW flow aloft and opens the door to a cold front dropping in from
the north. This should spell relief from the heat and higher rain
chances mid to late next week.

&&

.AVIATION /12Z TAFS THROUGH 18Z THURSDAY/...
Issued at 703 AM EDT Wed Aug 13 2025

Low-end MVFR stratus will be a concern this morning before ceilings
improve after 16Z. IFR/LIFR fog will likely linger at HNB through
13Z or so before vsbys steadily improve. Light winds will veer W/NW
today ahead of a cold front dropping in from the northwest. Isolated
to scattered shra/tsra are expected this afternoon and evening, but
confidence is not high enough in coverage to go even PROB30 at all
terminals. There is a growing signal for areas of dense fog early
Thursday morning.

&&

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

&&

$$

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