textproduct: Louisville

KEY MESSAGES

* Shower and storm chances will continue tonight through Sunday morning. Excessive rainfall is likely across southern Indiana and portions of northern Kentucky. A Flood Watch is now in effect for portions of southern Indiana and the Louisville Metro.

* Summer heat and humidity will build across the region next work week, with triple digit heat indices likely (60-80% chance) west of I-65 on Monday and area-wide by Tuesday. This will pose a risk for heat-related illness, especially among vulnerable populations.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 349 PM EDT Thu Jun 25 2026

A surface low in the Great Lakes region is slowly getting pushed off to the east. The system's trailing cold front is dropping south through Michigan, Indiana, and back towards the Plains. South of this front, moisture in the Lower Ohio Valley is pooling with precipitable water values between 1.6 to 1.8 inches as Gulf moisture continues flowing into the region.

This afternoon and evening, diurnal warming will help to generate scattered showers and thunderstorms ahead of the front across southern Indiana before drifting southeast. During this time, higher precipitable water values will continue inching in from the west ahead of the front, increasing values to 1.8 to 2 inches. This could lead to thunderstorm being able to quickly drop a couple of inches of rain fairly quickly. We could see some ponding on area roadways and in poor drainage areas. 6-Hour Flash Flood Guidance shows values between 2.5 to 4 inches, so we should be able to take some water before widespread issues are observed. Not expected widespread severe weather, but with around 1,500 J/kg of MLCAPE and steep low level lapse rates, a few strong gusts will be possible from any thunderstorm.

Tonight, showers and thunderstorms are expected to continue before possibly tapering off late in the night. Even if convection weakens, chances will remain through the night along and north of Interstate 64. None of this activity is expected to be severe, but a flooding concern remains if showers and thunderstorms begin to train along the boundary. Remaining cloud cover and continued WAA are expected to keep low temperatures in the mid 60s to near 70.

Tomorrow, with precipitable water values expected to reach over 2 inches ahead of an approaching surface low, an MCS type system is expected to reach southern Indiana and central Kentucky. With the heaviest precipitation expected on the northeast side of the low, the highest rain chances remain north of the Ohio River, including in the location of the current Flood Watch. With future forecasts the watch could be adjusted if needed. As bands work around the low, waves of showers and thunderstorms are expected to work east through Kentucky. This is expected to give breaks between any heavy rain showers, reducing the flood threat across central Kentucky. WAA will help temperatures reach into the 80s.

Friday night, as the low nears, a low level jet is expected to work over the CWA. This will drive further shower and storm chances, keeping the flood threat in place into Saturday morning.

LONG TERM /SATURDAY THROUGH THURSDAY/

Issued at 349 PM EDT Thu Jun 25 2026

Saturday, there remains some uncertainty on how far the cold front bringing all the rain in the short-term will push through the CWA. Global models tend to keep the front closer to the Ohio River, making for another wet day across southern Indiana and central Kentucky, but some CAMs have a more progressive solution, dropping the front farther south. This would make for a more dry day across the CWA. Believe rain chances will remain, but the flood threat will be reduced with lower expected rainfall totals. Either way, this should be the last day of widespread rain.

Sunday, summer arrives. An upper ridge axis advances east towards the CWA where it is expected to remain through at least the end of the workweek. Skies are expected to become mostly clear on Sunday and remain through the rest of the week. With high pressure at the surface, winds will ease to near calm. Dew points in the low 70s and temperatures climbing through the mid and possibly upper 90s will make it feel hot and sticky. Heat products currently look likely.

AVIATION /18Z TAFS THROUGH 00Z SATURDAY/

Issued at 216 PM EDT Thu Jun 25 2026

South of a stalled boundary over southern Indiana moisture levels are increasing. This is expected to lead to shower and thunderstorm development this afternoon and evening. Developed convection will then drift southeast, impacting HNB and SDF. Heavy rainfall and lightning are the main concerns, but gusty winds will also be possible. Visibilities will be reduced in areas with heavy rainfall. Tonight, conditions are expected to improve before more rain showers and storms return tomorrow morning.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Flood Watch through Saturday morning for KYZ030. IN...Flood Watch through Saturday morning for INZ076-077-083-084- 089>092.