textproduct: Louisville

KEY MESSAGES

* Heat and humidity continue to build for the end of the weekend into the start of next week. There is a 60-70% probability of reaching Heat Advisory criteria by the middle of the week.

* Major Heat Risk possible due to the multi-day duration of hot temperatures and little overnight relief. Anyone without effective cooling or adequate hydration will be susceptible to heat illness.

* A few shower and storm chances may return by late week, but current confidence is low.

SHORT TERM /THROUGH TONIGHT/

Issued at 358 AM EDT Sun Aug 30 2026

Upper ridging will continue to build over central CONUS today and as we go into the start of next week. Highs will be a little warmer today than they were yesterday as highs approach the low 90s. Thanks to dry air mixing towards the afternoon, dewpoints will likely lower into mid/low 60s helping to keep heat index values into the mid/upper 90s and could have a few gusts around 20 mph in the afternoon. Some scattered mid-level Cu could develop in the afternoon but expected to clear as we go into tonight. It will remain mild as lows fall to around 70 degrees.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 358 AM EDT Sun Aug 30 2026

Monday through Thursday Night...|

The overall forecast remains on track for the strong 594 dm 500mb ridge to continue to build and shift eastward over the Ohio Valley by the middle of next week. This will continue to keep us dry with daily max temperatures gradually increasing each day. While we will see increased low-level moisture, daily afternoon dry air mix down will result in dewpoints in the upper 60s with a few locations into the low 70s. Latest LREF show a 60-80% probability of heat index values over 100 for Tuesday through Thursday. Given the long duration of 90+ degree highs, warm overnight temperatures and daily heat index values near or slightly below the 105 Heat Advisory criteria and after collaborating with our neighboring offices, heat related headlines will likely be needed.

As was pointed out in the previous discussion, a few areas in our CWA like those over the Bluegrass where there has been higher than normal precipitation over the last 30 days, could result in lower high temperatures due to evaporation of moisture in the ground and vegetation. Other areas along and west of I-65 and points south have the higher probability of seeing hotter temperatures over the next several days.

End of the Week into Next Weekend...

Deterministic models continue to show the upper level ridge flattening and retrograde slightly westward. A back door frontal boundary may try and attempt to drop south into the region and stalls. NBM guidance continues to show widespread 30% PoP both Friday and Saturday for isolated to scattered showers and thunderstorms but overall confidence remains low.

AVIATION /18Z TAFS THROUGH 00Z TUESDAY/

Issued at 132 PM EDT Sun Aug 30 2026

VFR conditions will continue through the whole TAF period. SCT cumulus clouds will continue through the afternoon and maybe spawn a shower near LEX-RGA, but most likely all terminals stay dry. These clouds will dissipate as SW winds weaken to light and calm overnight with high level clouds hanging around. Similar conditions expected tomorrow with cumulus returning in the afternoon and a return of SW winds. VFR conditions expected at the end of the TAF period.

LMK WATCHES/WARNINGS/ADVISORIES

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