textproduct: Louisville

KEY MESSAGES

* A few pockets of light rain (20% chance) will be possible across the Bluegrass Region this morning. Otherwise, hot and humid today with afternoon highs in the low to mid 90s. A Heat Advisory remains in effect today through Thursday.

* A strong ridge of high pressure over the region will bring the hottest temperatures so far this year. The heat will peak Tuesday through Thursday, with afternoon highs in the mid 90s and peak index values of 105+.

* Hot and humid for the Fourth of July holiday weekend, with isolated to scattered storms possible in the afternoon and evening.

SHORT TERM /THROUGH TONIGHT/

Issued at 340 AM EDT Mon Jun 29 2026

A warm front stretches southeast through central Indiana and the Bluegrass Region early this morning. GOES-East Nighttime Microphysics RGB imagery shows a band of lower level clouds along this boundary. We even have a few tiny showers drifting through portions of Shelby, Anderson, and Mercer counties at the time of this writing. There is a notable Theta-E gradient across the warm frontal boundary. Despite increasing subsidence aloft, modest low- level convergence should lead to additional isolated showers in the Bluegrass Region. There is a slight chance (20%) for a brief shower through the morning hours, with the warm front lifting northeast of the area by 18Z today.

Conditions will be hot and oppressively humid this afternoon and evening. An upper level ridge will continue to build over the region, with the center of the mid-level ridge moving over western TN/KY. Despite a scattered cumulus field, temperatures will have no trouble rising into the lower 90s in most places. A few spots west of I-65 and the Louisville Metro may briefly top out in the mid 90s. Sfc dewpoints are forecast to remain in the mid and upper 70s, yielding afternoon heat indices in the 100-109 range. No changes are planned to the Heat Advisory for today. The HREF's probability for an apparent temperature greater than 109 is only 10-20% in the far western CWA (Dubois, Perry, Hancock, Ohio counties). Tonight will be dry and quite warm, with lows only in the mid 70s.

LONG TERM /TUESDAY THROUGH SUNDAY/

Issued at 340 AM EDT Mon Jun 29 2026

The upper level ridge overhead will peak in intensity Tuesday through Thursday, and this is when we will see the hottest temperatures of this heat wave. Afternoon highs in the mid 90s are likely each day. Peak afternoon and evening heat index values of 105- 110 are also likely Tuesday - Thursday. The probabilistic HeatRisk tool shows very high probabilities (90-100%) for major or higher heat-related impacts, affecting anyone without cooling/hydration as well as health systems and industries. Drink water, stay in the A/C if possible, stay out of the sun, and check up on family, friends, and neighbors.

The mid and upper level ridge begins to break down heading into the holiday weekend, with multiple mid-level shortwave disturbances forecast to ride east across the Midwest and Great Lakes. With a hot and humid airmass still in place, a chance (30%) of scattered pulse convection returns for Friday - Sunday. A weaker ridge and afternoon pulse convection will allow highs to settle back into the lower 90s over the weekend.

AVIATION /12Z TAFS THROUGH 18Z TUESDAY/

Issued at 708 AM EDT Mon Jun 29 2026

SCT VFR clouds between 3500-5000 ft will be common today, with the lower clouds eventually clearing out this evening. Winds will be light out of the southwest, generally 4 to 7 kts today. Patchy fog will be possible late tonight into early Tuesday morning.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Heat Advisory from noon EDT /11 AM CDT/ today to 9 PM EDT /8 PM CDT/ Thursday for KYZ023>043-045>049-053>057-061>067- 070>078-081-082. IN...Heat Advisory from noon EDT /11 AM CDT/ today to 9 PM EDT /8 PM CDT/ Thursday for INZ076>079-083-084-089>092.