textproduct: Louisville

KEY MESSAGES

* Scattered showers and thunderstorms continue bringing threats of isolated flash flooding, lightning, and gusty winds this afternoon and evening.

* Rounds of showers and thunderstorms are expected late week through the weekend along a slow moving frontal boundary. Flash Flooding, including potential for significant flash flooding, could develop late week through the weekend with repeated rounds of heavy rain.

* Additional threats of gusty to damaging wind could develop with complexes of thunderstorms moving into the area. Overall confidence is low with regard to timing of these specific threats.

UPDATE

Issued at 1224 PM EDT Wed Jul 8 2026

Lifted a longer duration Flash Flood Watch for the entire CWA in coordination with surrounding offices. The headline will start tomorrow afternoon and run through late Saturday evening. May have to adjust it some once each successive wave of rain become more clear, but for now it appears the entire area has a threat of flooding during this stretch. Multiple waves of showers and thunderstorms are expected from as early as Thursday afternoon until late Saturday evening. Several inches of rain are possible during this stretch, especially for areas that see repeated rounds. Several factors will contribute toward intense and efficient rainfall rates including moderate instability, high freezing levels, some training potential, and slow storm movement at times.

SHORT TERM /THROUGH TONIGHT/

Issued at 348 AM EDT Wed Jul 8 2026

Today, an upper low, embedded in a weak upper trough, is expected to get picked up by zonal flow. Stronger upper flow remains well north of the region which is causing the Lower Ohio Valley to lack meaningful wind energy, but we continue to have plenty of moisture with precipitable water values between 1.8-2" covering most of our CWA. Our top row of Indiana counties is in an area with slightly less moisture with PWATs between 1.6-1.8".

This afternoon, diurnal warming will once again increase MLCAPE instability to between 1,300 to 1,800 J/kg which might be slightly less than what we saw yesterday, but we can expected scattered slow moving showers and thunderstorms to pose an isolated flooding threat for any area that gets stuck under a heavy downpour. Highs are expected to reach into the 80s with dew points in the low to mid 70s.

Tonight, we start to see the pattern change as what was the upper low begins to move east out of the area. This will begin the movement of the higher PWATs eastward. The high PWATs won't make it out of the area before Thursday morning, but any remaining showers and thunderstorms will begin dissipating as we lose diurnal heating. Patchy fog will once again be possible as temperatures fall. Lows are expected to drop to either side of 70.

LONG TERM /THURSDAY THROUGH TUESDAY/

Issued at 348 AM EDT Wed Jul 8 2026

Thursday, as the remnants of the former upper low gets carried off to the east, PWATs try to drop below 1.5". The day might not be completely dry, but any diurnally driven chances for showers and thunderstorms will likely be more isolated than they have been. As a surface low begins approaching the Lower Ohio Valley from the west, an increasing pressure gradient and added WAA will help drive slightly warmer temperatures, closer to 90 along and west of Interstate 65.

Thursday evening into the early night, there is a chance that a system will continue moving east from the Plains and make it's way into the Lower Ohio Valley. Even though shear over the region is low, higher instability values could help an already developed system to sustain itself. This could bring a threat of strong to severe winds before weakening as the system moves off to the east later in the night.

Friday into the weekend, a messy west to east oriented boundary is expected to set up and drop south through the Ohio Valley. This is expected to bring a return of PWAT values over 2". There could be some marginal instability at times, but overall the severe threat looks fairly low at this point. The main concern is expected to be flooding. Unlike the earlier activity Thursday evening which is expected to be quick moving, some of the later activity along the boundary Friday and Saturday could possibly be slower moving and see multiple rounds of heavy showers causing increased chances for flash flooding. If we get breaks in rounds of rain, the region will see less issues than if areas don't get a break from continuous showers.

Early next week, precipitation chances look to finally drop as moisture gets pushed south of the CWA. High pressure behind the front is expected to bring clearer skies and slightly warmer temperatures in the low 90 degrees.

AVIATION /18Z TAFS THROUGH 00Z FRIDAY/

Issued at 131 PM EDT Wed Jul 8 2026

A low pressure system centered around the MO/IL/KY state line will meander eastward across the area through tonight, triggering scattered afternoon-evening showers and thunderstorms. With storms ongoing, the highest chances at the airfields will be over the next 6 hours, which was captured in prob30 groups. However, there is a lower (20-30%) chance thunderstorms could linger for another couple hours beyond 00z. By around 09z Thursday morning, patchy fog and low stratus is forecast to develop over the area; tempo groups were added at the terminals where confidence was highest.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Flood Watch from Thursday afternoon through late Saturday night for KYZ023>043-045>049-053>057-061>067-070>078-081- 082. IN...Flood Watch from Thursday afternoon through late Saturday night for INZ076>079-083-084-089>092.