textproduct: Louisville

KEY MESSAGES

* Flash flooding concerns remain as heavy rainfall chances remain in parts of the area through Saturday night.

* Summer heat and humidity build across the region next week, with triple digit heat indices likely (70-90% chance) west of I-65 on Monday and area-wide Tuesday through at least Friday. This will pose a risk for heat-related illness, especially among vulnerable populations.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 426 PM EDT Fri Jun 26 2026

The Lower Ohio Valley sits under the right entrance region of an upper jet while an 850 jet is beginning to push in from the west. This is pulling moisture along a stationary front sitting near central Indiana. Just to the west, over southeast Missouri and southwest Illinois, precipitable water values are reaching over 2.1" in an area with MLCAPE values around 1,500 J/kg. Over southern Indiana and central Kentucky, instability it trying to recover from earlier convection.

In the coming hours into the overnight, the system will slide east, south of the front. The very high PWATs will move eastward along the Ohio River as the low level jet increases to around 35 knots over the area. This is expected to produce heavy showers and thunderstorms. This afternoon and evening, the severe threat isn't overly concerning, but if instability is able to recover, a few strong storms could be possible. Overall the severe threat is expected to remain fairly low with flooding being the main concern over southern Indiana and north central Kentucky, so our counties along and north of Interstate 64 will remain in a Flood Watch until 12z tomorrow. Later in the night, showers and thunderstorms are expected to move with the high PWATs farther south into southern Kentucky. We issued a Flood Watch for the rest of our counties in Kentucky beginning at 6z tonight to cover the increased threat. With training possible and the HREF showing 6-Hour Probability-Matched Mean totals reaching as high as 3-4 inches in south-central Kentucky during the day Saturday for multiple runs now, the watch will run through 6z Sunday for when we believe the highest threat exists.

WAA will keep lows near the dew points in the low 70s to upper 60s. Tomorrow as winds veer slightly towards the southwest, as surface low pressure pushes in over central Indiana. With some small periods of sunshine being possible, temperatures are expected to climb into the low to mid 80s with dew points in the low to mid 70s.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 426 PM EDT Fri Jun 26 2026

Into the day Sunday, PWATs are expected to begin decreasing from the northwest ahead of a northwest to southeast oriented warm front that is expected to push east across the CWA Sunday morning, producing the last round of showers before precipitation finally comes to an end.

Later Sunday through the rest of the week, an upper ridge axis will advance east towards the CWA, brining a major shift in the weather pattern. Dew points in the low 70s and temperatures climbing through the mid and upper 90s will make it feel hot and sticky. High pressure under the ridge should keep winds light, providing little in the way of relieve as heat indices climb into the 90s to low 100s.

AVIATION /00Z TAFS THROUGH 06Z SUNDAY/

Issued at 753 PM EDT Fri Jun 26 2026

A cluster of storms is moving northeast dropping visibilities to MVFR/IFR conditions and ceilings to MVFR heights temporarily. Main threat is gusty winds and lightning within these storms as they move east through the evening. Once this cluster clears, spotty showers and storms will linger overnight with ceilings dropping to MVFR conditions across HNB/SDF/LEX. Except for lowered ceilings in storms, high end MVFR ceilings are expected for BWG in the morning. Multiple rounds of storms are expected tomorrow with near MVFR conditions continuing Saturday morning.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Flood Watch through Saturday morning for KYZ030>043-049. Flood Watch from 2 AM EDT /1 AM CDT/ Saturday through late Saturday night for KYZ023>029-045>048-053>057-061>067- 070>078-081-082. IN...Flood Watch through Saturday morning for INZ076>079-083-084- 089>092.