822
FXUS63 KLMK 220528
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
128 AM EDT Tue Jul 22 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

* Scattered showers and storms are expected this afternoon and
  evening over southern Kentucky. Heavy rainfall, gusty winds, and
  lightning are the main threats in storms.

* Hot and very humid for the second half of this week, with
  prolonged impacts from excessive heat possible.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 252 PM EDT Mon Jul 21 2025

An outflow boundary from early morning convection still remains over
southern Kentucky, which is the main focus for showers and storms
developing over central Kentucky. At the same time, a back-door cold
front is sinking south and colliding the with outflow. This will
lead to addition lift over this region. Sufficient lift, reaching
convective temps, and PWATs near or above 2.0 inches are all
ingredients for heavy rain. Scattered showers and storms will
continue through the afternoon and into the evening as these
boundaries interact and as some vorticity shedding moves along some
departing northwesterly flow aloft and over the southwestern portion
of the region. Precip chances will be greater along I-64 and south
and especially along the parkways and south.

Showers and storms will dissipate after sunset. Dew points will drop
into the mid 60s over the northeastern half of the region, bringing
some nice temperature relief over these areas. The cold front will
continue to push southwest, and begin to stall out. With rain
expected this afternoon, light winds, and scattered skies could see
some fog development in these areas. Low temperatures will range
from the low-to-mid 70s in the southwest to the low-to-mid 60s in
the northeast.

In the morning, fog will begin to burn off by mid-to-late morning.
The weakening front over the southwest portion of the region will
keep flow mostly northeasterly on Tuesday which will help to keep
dew points on the dry and more comfortable side. Areas in the far
southwest will likely still see oppressive conditions. Scattered to
broken skies will help to limit some heating, but still expecting to
see high temperatures in the mid-to-upper 80s and low 90s. We will
likely see our first break in daily precip as ridging begins to
build over the region.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Issued at 252 PM EDT Mon Jul 21 2025

Tuesday Night through Thursday Night...

Ridging will continue to build over the region and the surface front
will weaken to the southwest of the region. High pressure will begin
north of the region and slowly move east of the region, which will
allow for southerly flow and moisture to return to the region.
Ridging will lead to increased temperatures and southerly flow will
increase dew points over the region. Temperatures will be in the low
to mid 90s and dew points will be in the mid 70s in the afternoon.
The western portion of the region will see heat indices 103-106F and
the eastern portion will see 98-103F.

Not expecting to see much relief in the overnight hours as
temperatures will likely only fall in to the mid 70s. Warm minimum
records at most sites should remain, but will have to watch BWG
closely.

Looking to see dry conditions through this period, although wouldn`t
completely rule out a few isolated storms.

Friday through Sunday...

As we go into the weekend, ridging will begin to break down as a
series of shortwaves move along the northern CONUS. This will bring
daily shower and storm chances back into the Ohio Valley. With
heights over the region remaining high, temperatures will also
remain elevated. Continued southerly flow will keep high dew points
and moisture in the region, not seeing much relief from hot, humid,
and oppressive conditions in the long term.

&&

.AVIATION /06Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 127 AM EDT Tue Jul 22 2025

A backdoor cold front will try to push through the area from NE to
SW this morning, but is only expected to clear LEX, SDF, and maybe
RGA. Behind the front, drier air near the ground should limit fog
and stratus potential. At HNB and especially BWG, continued moist
air near the ground should lead to fog and low stratus this morning.
LIFR or lower conditions are possible at BWG, with fog expected to
set in around 08Z and continuing until 13-14Z. Moisture should
scatter up into a stratocu layer by mid-late morning, and VFR
conditions are expected at all sites from midday through the end of
the current forecast period. Winds should be out of the NE at 5-10
kt this afternoon. While a stray shower or storm is possible at BWg
this afternoon, coverage will be isolated, so we`ll leave mention
out of the forecast for now.

&&

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

&&

$$

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