175
FXUS63 KLMK 091205
AFDLMK

Area Forecast Discussion
National Weather Service Louisville KY
805 AM EDT Thu Oct 9 2025

...Updated Aviation Discussion...

.KEY MESSAGES...

*  With strong surface high pressure over the Great Lakes today,
   breezy northeast winds are expected. Plenty of sunshine today,
   with highs in the upper 60s to low 70s.

*  Friday morning will be the coolest of the season so far, with
   lows in the mid 30s to lower 40s. Some patchy frost will be
   possible in sheltered, rural valleys of southern Indiana and
   north-central Kentucky.

*  Dry conditions are expected through the weekend.

*  Gradual warming trend possible for early next week, possibly
   seeing highs in the upper 70s to lower 80s.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 254 AM EDT Thu Oct 9 2025

The upper flow pattern features low amplitude ridging over the
central US and troughing over the northeast. At the sfc, a strong
high pressure system is sliding across the Great Lakes today. Our
region will continue to be within a strong pressure gradient on the
southern side of the sfc high, so breezy NE winds throughout today
will provide a CAA regime. Similar to yesterday, wind gusts
exceeding 20 mph will be possible, especially during the afternoon
hours. This pattern will help keep our temps cooler than normal,
with highs in the upper 60s to low 70s despite abundant sunshine.

The pressure gradient will relax by tonight as the sfc high shifts
east of the Great Lakes, resulting in our winds to be nearly calm
overnight. Combined with the cool airmass in place, and very clear
skycover, tonight will be a good candidate for exceptional
radiational cooling and resulting in our coolest temps of the season
so far. Lows overnight are forecast to drop into the mid-30s for the
northern half of the forecast area, but would not be surprised to
see a few reports of mid-30s in our typical cool spots or valleys.
For south-central KY, temps are expected to remain in the lower 40s.
Given these low temps into Friday morning, some patchy frost will be
possible, especially for any sheltered rural areas across southern
Indiana and north-central Kentucky.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 254 AM EDT Thu Oct 9 2025

===== Friday and Friday Night =====

Strong sfc high pressure will be centered over the northeastern US
by Friday, with a somewhat split flow in the upper level pattern.
Amplified upper ridge will be building across the central US, with
upper troughing taking place over the southeastern US. A deepening
closed low will be diving south out of Canada and will be near the
northern Great Lakes region through the day.

After a chilly start, developing S flow will support weak WAA, and
we will see temps rebound nicely into the low 70s across the board.
Friday looks to be a great day weather-wise, with a mix of sun and
diurnal clouds through the afternoon. Temps for the overnight are
expected to cool into the upper 40s for most.

===== This Weekend and Early Next Week =====

The upper closed low will meander over the Great Lakes throughout
the weekend, though we may see an increase in upper level clouds
spreading south and over our area on Saturday. A weak cold front
will also shift south of the Great Lakes, though is expected to wash
out before making it to the Ohio River. A lack of moisture and
forcing should keep this front from producing any precip this far
south. The GFS ensemble has about 8 members that indicate at least a
trace of rain to be possible over the weekend, though the Euro and
Canadian ensembles are drier. Will stick with a dry forecast for the
weekend. Temps over the weekend will feature highs in the mid 70s,
along with morning lows in the upper 40s.

As we get into early next week, the upper low over the Great Lakes
will eventually merge with a coastal trough, which will likely keep
any substantial moisture to the east of the Appalachians. Upper
ridging will be shifting east of the Mississippi River, keeping a
dry pattern in place, but with a warming trend for the first half of
next week. Highs in the mid 70s to near 80 will be possible.

&&

.AVIATION /12Z TAFS THROUGH 18Z FRIDAY/...
Issued at 804 AM EDT Thu Oct 9 2025

Clear skies and VFR today. Breezy NE winds of 10-12 kts. Cannot rule
out a brief, occasional gust of 15+ kts from mid-morning through mid-
afternoon. Winds will diminish this evening with sunset.

&&

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

&&

$$

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