153
FXUS63 KLMK 142307
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
707 PM EDT Tue Oct 14 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

*  Dry conditions are expected through the rest of the workweek with
   highs mostly in the 70s.

*  Strong frontal boundary to move through the region late Saturday
   and into Sunday. Strong thunderstorms will be possible during
   this time frame with 1-2 inches of rainfall.

*  More dry weather to follow for early next week.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 328 PM EDT Tue Oct 14 2025

It is a very pleasant day across the region, with sfc high pressure
and upper ridging dominating the weather for us. Temps are in the
mid to upper 70s, though a few isolated spots hitting 80 are
beginning to show up on the KY Mesonet map despite breezy NE flow.
By this evening, winds will relax, leading to a nice night with
mostly clear skycover and temps dropping into the upper 40s to low
50s. With light winds and clear skycover, we could see some patchy
fog develop in the early morning hours, especially in the river
valleys.

For tomorrow, mostly sunny conditions are anticipated, though a very
weak and moisture-starved cold front looks to drop south through the
region during the day. Hi-res guidance suggests maybe a few light
showers well north of our area, but our atmospheric profile will be
dry enough to not have any precip mention. We`ll likely see temps
range some from north to south across the forecast area, with the
Bluegrass region limited to the low 70s, but approaching 80 across
south-central KY.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 328 PM EDT Tue Oct 14 2025

===== Wednesday Night - Friday Night =====

Amplified upper ridge will build over the eastern US for the second
half of the work week, which will continue to influence dry and
sunny weather for the Ohio Valley. Temps will be near normal on
Thursday, though could be slightly warmer on Friday as we tap into
WAA regime with the sfc high shifting off to the East Coast. Clouds
will also be on the increase for Friday, which could play into a
lower confidence on high temps for the day.


===== Heavy Rain This Weekend  =====

By Saturday, the upper ridge axis will slide east of the region,
opening the door for a pronounced digging upper trough over the
central US to shift eastward. Though the sfc low will be tracking
across southern Canada, the trailing cold front will be quite strong
as it trails extensively into the southern Plains. The sfc pressure
gradient out ahead of the cold front will be tightening, leading to
gusty southwest winds before any rain arrives. This SW flow pattern
will ramp up the WAA regime, leading to temps to likely hit the
upper 70s and low 80s, along with rising dewpoints as we begin to
tap into a deeper Gulf moisture fetch. We could see rain showers
begin entering the CWA from the west by Saturday afternoon, but the
best forcing and most moisture arrives for Saturday night.

By Saturday night, the LLJ increases ahead of the approaching cold
front, possibly exceeding 45kts in the 850mb layer. This will
further ramp up the moisture transport axis across our area, leading
to PWAT values approaching 1.6". The 100-member LREF indicates a 30%
chance for PWATs exceeding the 1.6" threshold, which would be around
the daily max for sounding climo from BNA for this time of year.
However, the question remains how much of the jet core will make it
down to the sfc overnight if a nocturnal inversion can hold.
Regardless, our forcing and moisture will be maximized through
Saturday night ahead of the cold front, leading to a line of
moderate to heavy rainfall and embedded thunderstorms passing
through the area. A widespread 1-2 inches of rain is expected,
though locally heavier amounts will be possible. We may see some
localized flooding issues, but the residence time of moderate rain
appears to be short enough to limit widespread flooding concerns.

There also exists a low-end severe risk for our area, but as
mentioned in prior discussions, the timing of the cold front being
overnight could play in our favor for mitigating severe risk. The
best chances will be along the Mississippi River, and western KY, as
highlighted by the SPC D5 outlook. The NSSL ML guidance outputs a
10% chance for total severe probs, with a 15% across western KY and
southern IL/MO. Model soundings show a high shear low CAPE
environment, which should be no surprise given the racing LLJ
overhead during the nighttime hours.

By Sunday morning, the cold front will be sliding east of the I-65
corridor. Additional showers and storms will be ongoing throughout
Sunday as well, though the LLJ core and moisture transport axis will
be sliding east with the front, leading to less forcing and
moisture. In a post-frontal regime, combined with heavy cloud cover,
temps on Sunday will be limited to the 60s. The upper trough axis
will eventually clear east of the area by Sunday afternoon/evening,
which will result in decreasing cloud cover later in the day.


===== Early Next Week =====

The upper trough deepen into a closed low over the Mid-Atlantic by
Monday, though ridging will be building across the Midwest. We`ll
have sfc high pressure extend up into the TN Valley for next week,
which will keep a dry forecast. Temps will be near normal with highs
right around 70, and lows in the 40s.

&&

.AVIATION /00Z TAFS THROUGH 06Z THURSDAY/...
Issued at 706 PM EDT Tue Oct 14 2025

VFR conditions this evening will continue for the overnight
period. Winds are beginning to relax now after having some gusts
earlier in the day. Expect light NE winds overnight, perhaps with
some patchy fog in the valleys. Currently do not expect any vis
impacts to terminals overnight. VFR conditions continue for
tomorrow as well, with winds from the northeast.

&&

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

&&

$$

SHORT TERM...CJP
LONG TERM...CJP
AVIATION...CJP