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.

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 /06Z TAFS THROUGH 12Z THURSDAY/

Issued at 146 AM EDT Wed Jul 8 2026

The trend from the last few days continues with lots of moisture at the surface. Areas that saw rain showers earlier in the day are more likely to see fog tonight, but there is a decent amount of cloud cover that will limit cooling, limiting fog development to some degree. Parts of the region, mainly southern and eastern Kentucky, could see fog drop visibilities into IFR levels. This could happen at LEX, BWG, and RGA. More optimistic at SDF and HNB where MVFR could happen, mainly at HNB. Later in the day, more scattered slow moving showers and thunderstorms are expected to develop across the region.

LMK WATCHES/WARNINGS/ADVISORIES

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