textproduct: Louisville

KEY MESSAGES

* Scattered thunderstorms (30-50% coverage) are forecast mainly along and southeast of the Western Kentucky and Bluegrass Parkways this evening. There is a level 1 of 5 (Marginal) risk for severe weather, with locally damaging winds the primary hazard.

* Cooler weather will gradually overspread the area this week, with highs likely in the 70s north of an Owensboro to Stanford, KY line tomorrow, and area-wide Wednesday through Saturday.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 247 PM EDT Mon Sep 21 2026

Things have been pretty quiet early this afternoon as the airmass tries to recover. The boundary that was sinking southward across Kentucky this morning has mostly washed out across the area, and starting to see some signs of a more unstable environment across southern KY where some agitated Cu are showing up on satellite. In addition, a 2000-2500 J/KG ML CAPE axis is starting to build into our SE CWA. The biggest question with this evening is whether storms will initiate? Not a lot of triggering available outside of diurnal heating and the synoptic front starting to get a push southward. If they do get going, it does appear that there will be enough deep layer shear (25-35 knots) for some updraft organization at least into some multicell clusters, if not a supercell or two. Pretty unidirectional shear profile with high LCLs and non-favorable low level wind shear will only promote a very isolated wind threat. No tornado threat if a supercell storm mode does develop. Overall coverage should stay isolated to widely scattered, so will mainly carry chance pops for areas along and south of the Western Kentucky and Bluegrass Parkways. There is a secondary area of an isolated chance of a shower or storm up along where the synoptic cold currently front sits, but confidence is pretty low in development here where instability is weaker. Overall, the best time frame for development looks to be 4-10 PM EDT.

A few showers or a storm could linger across the southern CWA into the overnight as the front gets a good push southward. However, overall convective trends should be downward. Could see a few gusts out of the N between 20-25 with the frontal passage, even after sunset.

Cooler air is more established over our area tomorrow behind the cold front. As a result, highs only make it into the mid and upper 70s across southern IN and northern KY. Across southern KY, temps should still hold onto the lower 80s during the afternoon. A few showers or a storm could linger across the SE CWA for tomorrow ahead of a weak shortwave trough axis approaching the area. Confidence isn't high, and the main story will be the overall cooler temperatures.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/

Issued at 247 PM EDT Mon Sep 21 2026

Wednesday - Monday...

The overall upper pattern will be pretty interesting by mid week as it will feature hybrid Omega/Rex blocking near and over our region. The main part of the Omega Block will stretch from the western Gulf Coast states up into eastern Canada. Meanwhile, the Rex Block will take shape as a cutoff low settles over Ohio. This closed upper low will be close enough to our region to support a few lingering precip chances mainly along the I-75 corridor on Wednesday. Outside of that, the rest of the CWA should be dry. Temperatures will be seasonable for this time of year ranging from the low 70s across southern IN to the upper 70s across southern KY.

As we move through late week, the aforementioned closed upper low will center more over the mid Atlantic states, with the Omega block getting a bit more established over our area. This will keep us dry, likely lasting through the weekend, possibly into early next week. Temperatures will continue to be seasonal for this time of year with highs in the 70s heading into the weekend. By Sunday/Monday, temps will likely start to trend back above normal and more into the low 80s. It's also worth noting that some cool/crisp mornings will be in store, with Saturday/Sunday mornings being the coolest. Looking for lows in the upper 40s and low 50s.

AVIATION /06Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 117 AM EDT Tue Sep 22 2026

For the overnight period, northeast winds will be seen at the terminals. Low clouds will continue affect the region with a mix of IFR/MVFR cigs through the overnight and into Tuesday morning. Some patchy fog may develop if winds slacken enough, however, latest data is keeping the winds up overnight which may keep the boundary layer mixed. Cigs will improve slowly after sunrise, probably around mid- late morning, with VFR conditions expected to return by mid-late afternoon. Winds through the daytime hours will remain out of the northeast.

LMK WATCHES/WARNINGS/ADVISORIES

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