textproduct: Louisville

KEY MESSAGES

* Pleasant and dry weather will continue through at least Tuesday with highs in the mid to upper 70s/low 80s and mostly clear skies.

* Temperatures will begin to warm back into the mid to upper 80s mid week ahead of rain chances returning late Thursday.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 325 PM EDT Sun Sep 27 2026

Comfortable conditions across the Ohio Valley continue as surface high pressure and northeasterly flow prevails across the region. With mostly clear skies expected tonight, decent radiational cooling will allow temperatures to drop to the upper 40s/low 50s. Isolated patchy river valley fog was observed this morning in the eastern portions of our area, and with this pattern holding through the early portions of the upcoming workweek, some isolated patchy fog cannot be ruled out Monday morning. For Monday and Tuesday, conditions will be fairly similar to today, with temperatures subtly increasing each day. Highs will be in the mid to upper 70s on Monday, with a return to the 80s on Tuesday. Overnight temperatures will also be similar, with lows continuing to be in the upper 40s/low 50s. By late Tuesday into Tuesday night, the area of surface high pressure will shift off to the east, allowing the return of southerly flow to the region. Overnight temperatures will be closer to normal for this time of year, with lows in the mid to upper 50s forecast.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Issued at 325 PM EDT Sun Sep 27 2026

Looking broadly at the synoptic scale, the remnants of Hurricane Polo interacts with an upper-level low over the SW CONUS late Tuesday into Wednesday, with the entire system moving northeastward towards the Ohio Valley. Over our area, the western edge of the ridge continues to persist, keeping us dry on Wednesday. With the return of southerly flow, the end of September will be very warm with highs in the mid to upper 80s and a few places reaching 90.

For Thursday, a shortwave trough over the Great Lakes region will interact with the surface ridge, with moisture from the previously mentioned upper-level low moving northeastward. Conditions will be dry for most of the day on Thursday before a cold front associated with the shortwave trough pushes southward towards the region. Rain chances will return, lasting through at least late Friday. From the latest LREF, rainfall totals range from 1-1.5" across the area, with higher amounts off to our west. The remainder of the forecast period becomes uncertain as there is high variability in deterministic and ensemble guidance. The uncertainty lies in the progression of the surface cold front and associated surface high pressure behind. Some guidance has the front pushing well to our south, keeping the area mostly dry next weekend, while other model outputs keep the front nearby with persisting rain chances through the weekend. With the high uncertainty, chance (< 50%) POPs are in the forecast package during this time frame.

AVIATION /06Z TAFS THROUGH 12Z TUESDAY/

Issued at 102 AM EDT Mon Sep 28 2026

VFR conditions are expected to continue through the forecast period. Winds are currently calm to light out of the north across the area. Valley fog will be possible through the night, but does not expected to impact TAF sites. A more northerly component will continue into the day with a slight increase to 5-10kts. Mostly clear skies with few to scattered high cirrus clouds moving in from the NW during the evening hours.

LMK WATCHES/WARNINGS/ADVISORIES

KY...None. IN...None.