textproduct: Louisville

KEY MESSAGES

* Dry and seasonable Labor Day expected with only a small chance of a shower or storm around the Lake Cumberland region by early evening.

* The hottest day of the week will be Wednesday with highs in the low to mid 90s and peak heat indices in the low 100s west of I-65.

* A cold front arrives Thursday morning with 70-80% chance of showers and a few storms possible. Fairly widespread rainfall amounts between .25" and .5" are currently expected.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 244 PM EDT Mon Sep 7 2026

High pressure centered to the northeast of the region is helping to provide quiet weather today. There is still a small chance for a few isolated showers and storms over the Lake Cumberland region later this afternoon. Little to no shear will prevent these storms from becoming severe. Though brief gusty winds and lightning will be possible. As instability wanes this evening, showers and storms will dissipate.

Upper ridging will shift slightly east and strengthen, which will increase temperatures into the low 90s on Tuesday and low-mid 90s on Wednesday. We will remain dry on Tuesday and most of Wednesday as subsidence continues to hold over the region. Heat indices on Wednesday will be in the 95-105 range, with 100-105 along and west of I-65. A Heat Advisory will be possible for Wednesday.

On Wednesday, the pressure gradient will increase as a strong system begins to move into the upper Midwest. Coupled with daytime mixing, expecting to see breezy conditions (20-25mph) on Wednesday afternoon.

LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/

Issued at 244 PM EDT Mon Sep 7 2026

Wednesday Evening - Thursday Night...

As the aforementioned strong system moves through the upper Midwest and Great Lakes, this will bring a cold front through the Ohio Valley. Along and ahead of this cold front, widespread showers and storms are expected. Troughing associated with this system will brush the northern half of the region. This will place better shear values (35-40kts) over the northern half of the region. Southerly flow will continue to pump moisture into the region as dew points will be in the low-mid 70s Wednesday and Thursday. PWATs will increase to about 2.0 inches ahead of the cold front. A strong LLJ looks to set up right along the front, which may lead to some convective training over the northern half of the region. As of this forecast, there is a chance for Marginal severe storms and flooding. Looking to see a widespread 0.25-0.5 inches of rain, with areas in southern Indiana and northern Kentucky seeing up to 1 inch. The limiting factor for severe storms will be instability, depending on the timing of this front. Currently, the cold front is expected to approach the region Wednesday evening and slowly push south through Thursday as troughing aloft weakens.

Friday - Sunday...

High pressure will follow the cold front and help to bring temperatures back into the mid 80s. Chances for isolated to scattered showers and storms will remain over the southern half of the region into the start of the weekend. These chances will steadily creep north through the weekend as returning southerly flow increases temperatures and moisture. There is weak overall flow, so details will become clearer over the next few forecast cycles.

AVIATION /18Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 129 PM EDT Mon Sep 7 2026

VFR conditions are expected through this forecast period. High pressure will help to keep winds light and skies with a light Cu field. Winds this afternoon will vary from the north-northeast to the east around 4-9kts. In the evening, winds will relax to mostly variable around 3-4kts. Around sunrise, winds will veer to the south around 7-10kts.

LMK WATCHES/WARNINGS/ADVISORIES

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