textproduct: Louisville

KEY MESSAGES

* Very warm and humid conditions are expected this week with scattered afternoon/evening thunderstorms. Torrential rainfall, gusty winds, and lightning will be the main threats with this activity.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 318 PM EDT Tue Jul 15 2025

Remnant MCV is working over the Ohio Valley this afternoon and as it interacts with the moist unstable environment we will see bands and clusters of showers/thunderstorms that produce torrential rainfall. PWAT values are around 2.00", SBCAPE 2500-3000 J/kg with a storm motion of 15-20 mph this afternoon with no shear and poor mid-level lapse rates rates, the main impacts remain the heavy rainfall that could lead to very localized flooding and even ponding on area roadways this afternoon into the early evening. Storms will have frequent lightning and could get some gusty winds.

Some lingering convection towards eastern and southern KY is possible as we go into the evening but overall we may see a brief lull in activity before a a weak mid-level wave over the Ozarks this afternoon works across the area along the Ohio River and southern IN later tonight into tomorrow morning. Could see some enhanced lifting thanks to a 30kt LLJ and it looks to arrive late tonight and through the early morning hours with additional rain and thunderstorms with more heavy rainfall, as PWAT values remain around 2 inches, frequent lightning and a localized flooding concern as these showers/storms could work over the same places that saw the heavy rain this afternoon.

Mid-level wave works eastward during the morning hours of tomorrow with lingering showers/storms across our far eastern CWA at the start of the day. It will be generally more of the same with the muggy and very warm air in place but with continued weak ridging over the area tomorrow we may see more isolated than scattered convection in the afternoon and evening with highs in the upper 80s/low 90s and dewpoints in the low/mid 70s.

LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/

Issued at 318 PM EDT Tue Jul 15 2025

Shortwave trough ejecting out of the Pacific Northwest today will meet up with a developing sfc low across the Plains tomorrow and work across the Great Lakes Wednesday night into Thursday flattening out the ridge over the Ohio Valley and southeast US. An associated cold front will drop southeast out of Upper Midwest Thursday into Thursday night before stall along to just north of the Ohio River for the end of the week into the start of the weekend. We will remain in the very warm and juicy airmass with mainly diurnally driven convection each day as highs will be in the upper 80s/low 90s nearly every day with the exception of Thursday where highs could be in the low/mid 90s. As has been the trend the last several days, while we have convective chances each and every day, we continue to lack shear which keeps the overall severe threat low. Frequent lightning, gusty winds and heavy rainfall will continue to be the main impacts from any showers/storms that form over the next several days. Localized flooding with repetitive rounds of showers/storms will be the biggest overall impact.

AVIATION /18Z TAFS THROUGH 00Z THURSDAY/

Issued at 148 PM EDT Tue Jul 15 2025

The remnants of a MCV is working across the Ohio Valley this afternoon and is producing clusters of showers and thunderstorms that is producing heavy rainfall with them. These will likely be around most of the afternoon as this wave slowly works to the east- northeast providing enough lift for ongoing convection. The challenge is just timing and overall coverage. Kept PROB30 in for practically all locations this afternoon until around sunset. Other than that the flight categories should remain VFR outside of these showers/storms.

Bit of a break into the early evening but a second convective cluster associated with energy currently over northern AR and southern MO will start to work into the Ohio Valley overnight into the pre-dawn hours. Likely starting after 06z. This doesn't look severe but more of the same with heavy rainfall, occasional gusty winds and lightning. There isn't strong agreement on timing or even strength but added PROB30s overnight.

LMK WATCHES/WARNINGS/ADVISORIES

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