338
FXUS63 KLMK 041853
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
253 PM EDT Sat Oct 4 2025

.KEY MESSAGES...

*  Dry and sunny weather continues through the weekend.

*  Shower and storm chances increase early next week ahead of a cold
   front arriving on Wednesday.

*  Cooler and more seasonal temperatures arrive for the late week
   time period.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 252 PM EDT Sat Oct 4 2025

Not much going on across the region at this hour as a scattered cu
field has developed along with temps surging into the lower 80s.
Expect to get another couple/few degrees out of max Ts today with
good overall heating which should put just about everyone in the low
to mid 80s range.

Diurnal cu field diminishes this evening with good radiational
cooling conditions overnight. This will allow for some patchy river
valley fog. Lows drop down into the low and mid 50s for most. Some
lower 50s likely in the eastern valleys.

Upper ridge axis starts to slide east on Sunday, but still holds
plenty of influence over our area. Surface winds start to swing
around to a more SSE to S component, so possibly get a slight WAA
component to add to mostly sunny skies. Some late clouds may slide
in, especially across our south, but overall should be another well
above normal day with highs mostly in the mid 80s.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 252 PM EDT Sat Oct 4 2025

Sunday Night - Wednesday Morning...

The upper ridge axis and surface high pressure will be centered over
the mid Atlantic Coast as we move into the new work week. Meanwhile,
shortwave troughing will dig across the north central CONUS into the
Great Lakes, and will cause the ridge to lose influence while
bringing deeper SW flow into the Ohio Valley region. This will bring
a changes to the pattern for early through mid week with increased
shower and storm chances as well as cooler weather.

Sunday night should remain dry, however increasing sky cover should
keep overnight lows a bit milder and mostly in the upper 50s and low
60s. By Monday morning and through the day, return Gulf flow looks
to overspread the area, increasing PWATs and bringing some scattered
shower and storm chances. Most of the measurable precip should stay
along and west of I-65 through the daylight hours, with more
widespread shower and storm chances arriving Monday night into
Tuesday ahead of the main trough axis and approaching cold front.
The LLJ looks to ramp up to its strongest by this time, beneath an
increasing upper level wind field, so highest pops will be
associated with the increased forcing and deep moisture surge late
Monday night through Tuesday.

By Wednesday morning, the upper trough axis should be through the
area with the cold front also exiting our to our SE. This will bring
a drying trend from NW to SE across the area. By this time, the most
notable change will be temps with highs only in the low to mid 70s.
This 10 degree drop from Monday highs in the lower 80s puts us back
around or just below normal values for early October.

Overall QPF looks to range between .5" and 1" for most spots, so
could at least put a brief hold on steadily worsening drought
conditions. Likely won`t see any notable improvement from this round
of rainfall unless values increase a bit. For context, LREF
probabilities of .5" or greater range between 70-80% through
Wednesday, but probabilities drop off pretty steadily for values
over 1". Most likely area to get an inch or more would be on either
side of the Ohio River. Will also have to watch for some
thunderstorms, and the overall shear profile does increase. However
at the moment, it appears we lose the best low level jetting out
ahead of where the peak instability (which isn`t all that great to
begin with ML CAPE 500 J/KG) will be. We`ll monitor, but not overly
concerned about severe at this moment.

Wednesday Afternoon - Saturday...

Surface high pressure and relatively zonal and unremarkable flow
aloft takes hold for later Wednesday through Thursday. Another dry
period here, with temps much closer to seasonal values. Even
slightly below. Biggest story here will likely be the cool
overnights with lows in the mid-upper 40s and low 50s for many
Wednesday night and Thursday night.

Confidence lowers for the Friday night into Saturday time frame as
various solutions suggest another shortwave trough could dive into
the region. They vary significantly on timing/strength/placement of
of this feature, and its impact on sensible weather. Therefore, will
keep the forecast mostly dry for now with seasonable temp values.

&&

.AVIATION /18Z TAFS THROUGH 00Z MONDAY/...
Issued at 138 PM EDT Sat Oct 4 2025

Winds will generally be out of the south today around 5kts with some
scattered afternoon Cu. VFR will remain the main flight categories
through the forecast period. Not seeing a strong signal for fog as
we go overnight as we did last night so left it out for now. Winds
will remain light and out of the south with mainly clear skies
through the forecast as ridging aloft and high pressure off the east
coast of the CONUS keep weather fair.

&&

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

&&

$$

SHORT TERM...BJS
LONG TERM...BJS
AVIATION...BTN