textproduct: Louisville

KEY MESSAGES

* Heat Advisory is in effect through Thursday.

* Unseasonably hot temperatures continue.

* Low (20-30%) rain chances returns late in the workweek.

SHORT TERM /THROUGH THURSDAY/

Issued at 342 AM EDT Wed Sep 16 2026

An upper high remains over the Mid-Mississippi Valley, including over the Lower Ohio Valley. In the zonal flow on the northern side of the high, a cold front cuts through central Indiana. At the surface, a high sits off the New England Coast and extends southwest into the Southeast. This is directing southern flow with warm moist air from the Gulf into the Ohio Valley. With continued highs in the mid 90s with dew points in the low to mid 70s, heat indices are expected to reach to near 105 degrees today, and with little chance in the overall pattern, expecting about the same for Thursday. Had to bump dew points up a degree to get guidance to better match yesterday's heat indices and current values.

The CAMs continue to point to increased chances for isolated showers and thunderstorms south of the front, mainly across southern Indiana into the Bluegrass region. Still think most areas will remain mostly sunny with dry conditions being dominant, but a quick showers can't be ruled out.

Wednesday night will see winds ease under mostly clear skies, but light WAA will likely keep lows in the low to mid 70s. The low 60s are "normal" lows for this time of year.

LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/

Issued at 342 AM EDT Wed Sep 16 2026

Thursday night into Friday, we begin to see the upper high slide west towards Texas, pushing the ridge above it north through the eastern Plains and Midwest. Northwest flow, ahead of the ridge, will push a surface high through the Great Lakes region behind a cold front trying to work its way south through the CWA, which could bring northeast winds to southern Indiana and central Kentucky. This will likely increase rain chances to 20-30 percent. Models have been consistent with this feature for several days, so believe it could provide some bust potential with extending the heat advisory into Friday and/or Saturday.

With that said, by Saturday, the front is expected to begin moving back north as a warm front. WAA keeps high temperatures in the low to mid 90s through the weekend before upper 80s return on Monday for some. There is a general trend in precipitation chances increasing to 20-40 percent during the beginning to middle of next week as different waves work through the messy zonal pattern, but consensus is weak.

AVIATION /06Z TAFS THROUGH 12Z THURSDAY/

Issued at 205 AM EDT Wed Sep 16 2026

VFR conditions are expected to continue through the forecast period. Besides some high level clouds at times, skies will remain clear. Winds out of the south will begin to veer towards the southwest before backing towards the south again Wednesday night.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Heat Advisory until 8 PM EDT /7 PM CDT/ Thursday for KYZ023>034-038-045-046-053-054-061>065-070>077-081. IN...Heat Advisory until 8 PM EDT /7 PM CDT/ Thursday for INZ076>079-083-084-089>092.