textproduct: Louisville

KEY MESSAGES

* A cold front arrives today with 80-90% chance of showers and a few storms possible. Fairly widespread rainfall between .5" - 1" is expected with locally higher amounts over 1.5" possible, especially along and north of I-64. A few localized areas could see 3"+ which could lead to a some flooding concerns.

* This weekend is expected to remain active with off and on isolated to scattered showers and storms.

* Overall drier and hotter conditions arrive early next week.

SHORT TERM /THROUGH TONIGHT/

Issued at 240 AM EDT Thu Sep 10 2026

Scattered showers and a few storms will continue early this morning as subtle low level jetting (~25 knots) continues to respond beneath favorable right entrance region upper jet structure. As we move toward dawn and into the late morning hours, it appears there could be a bit of an uptick as shortwave energy ejects out of the Plains into the mid Mississippi River Valley. This will also occur as the weak surface frontal boundary will start to slide southward toward the Ohio River. The end result should be clusters of showers and storms capable of locally heavy rain and gusty winds. PWATs look to surge over 2" through the column, and with 500-1000 J/KG of ML CAPE expected we could see a few water loaded downbursts in the most intense precip cores. Later on this afternoon, ML CAPE values look to rise into the 1500-2000 J/KG range along and south of the Ohio River (ahead of the surface front). By this time, the overall deep layer shear will be weakened, especially in the low levels with the loss of the LLJ. Still, could get a few localized downbursts, along with a continued heavy rain threat thanks to high PWATs, relatively slow movement, and efficient rainfall processes. Still seeing some locally high values over 2-3"+ showing up in the HREF PMM data, which adds confidence to what the meteorological data showing the locally heavy rain potential is plausible. Don't have enough confidence in coverage and/or placement to focus Flood headline at this time, but will continue to message the potential for some low- end localized flooding concerns.

The surface front will be slow to push south, so will linger some shower chances into late tonight across KY, with southern IN likely staying more dry. Overall intensity should be somewhat diminished by this time with the loss of the best instability and the front starting to wash out.

The good news is that the increased shower and storm activity combined with the weak surface front dropping south will provide some relief in temperatures today, at least for southern IN and north central KY. Southern KY will still hold onto upper 80s and low 90s south of the surface boundary.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 240 AM EDT Thu Sep 10 2026

Friday - Saturday...

The weak surface boundary will be stalled somewhere near the KY/TN border on Friday, with a weak and meandering shortwave over the mid Mississippi River Valley. A high PWAT airmass will pool over our area ahead of this weak upper trough axis with showers and storm chances continuing mainly each afternoon and evening. The overall deep layer shear profile will be weak, so any slow moving storm may be capable of localized heavy rain given the high moisture content. 1000-1500 J/KG of CAPE in a tall/skinny profile combined with 2 - 2.25" PWATS, high freezing levels above 15K feet, and slow movement will be quite efficient with rain rates. Something to watch going into the first part of the weekend.

Temperatures each day will be mostly in the low and mid 80s, although the southern and western CWA could sneak into the upper 80s. Will keep pops pretty high through this period given the amount of deeper moisture and a triggering mechanism.

Sunday - Tuesday...

Looks to be a drier and hotter stretch of weather for the end of the weekend going into early next week. The southern CONUS ridge will build back over the area, pushing the stronger westerlies much farther north. This will put us in a mostly subsident and dry pattern as forecast soundings do show an impressive H7 inversion. Hotter temperatures will also accompany this upper pattern change with afternoon highs back in the upper 80s and low 90s by Tuesday.

Wednesday...

There seems to be fairly decent model agreement (for Day 7 anyway), that the upper ridge breaks down a bit by mid week, and allows a cold front to approach our region. This would bring a return of showers and thunderstorms to the area, if correct. In addition, temperatures would probably step back toward normal temps back in the 80s.

AVIATION /06Z TAFS THROUGH 12Z FRIDAY/

Issued at 133 AM EDT Thu Sep 10 2026

Things are mostly quiet at the TAF sites this hour, however a few clusters of showers are fairly close to BWG and HNB. VFR prevails this morning with a BKN mid deck of clouds expected to become more established with time. Also expect coverage of showers and perhaps a few storms to increase toward dawn and through the late morning hours. Highlighted these times with Prob30s, and then another Prob30 for expected afternoon T-storms as the cold front begins to move through the area. Surface winds will go from steady SW to NW with frontal passage, and then end later tonight as a NE surface wind. Any shower or storm could briefly reduce vis into the IFR, but will mention just low MVFR for now given uncertainty in timing. Some MVFR ceilings are also possible across the northern TAF sites as the front slides into the area later today.

LMK WATCHES/WARNINGS/ADVISORIES

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