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.

UPDATE

Issued at 1034 AM EDT Thu Sep 10 2026

Morning satellite imagery shows mostly cloudy skies across southern IN and much of central KY this morning. Some partial clearing was noted across southwest and far southern KY. Temperatures were mainly in the low-mid 70s under the clouds, but where filtered sunshine was noted, temperatures were in the upper 70s to near 80 along the KY/TN border.

Initial batch of morning convection continues to push on off to the east and is now located from Flemingsburg southwest to near Campbellsville. Convection seems to be aided by the nocturnal low- level jet axis which will continue to move eastward through the morning hours. Surface cold frontal boundary is still north of the CWA in central IN and will continue to track southward this morning.

For the remainder of the morning hours, we'll see a brief break in the rainfall from SE IN down into portions of north-central KY. However, another band of showers across southwest/southern IN will gradually work eastward ahead of the approaching frontal boundary from the north. Abundant cloud cover and ongoing precipitation will likely result in keeping stability across the region down this afternoon, with the exception of southern KY where filtered sunshine may allow MLCAPE values to get into the 1200-1700 J/Kg range this afternoon. However, the low-level jet axis will continue to move eastward and should be well east of the area this afternoon. We do expect storms to redevelop during the afternoon hours. Some strong storms are possible with wet microbursts being the primary threat posing a small damaging wind risk across the area. High moisture content will keep PWAT values up and some swaths of heavy rainfall are possible, yielding widely scattered instances of hydro issues across the region.

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 /12Z TAFS THROUGH 18Z FRIDAY/

Issued at 649 AM EDT Thu Sep 10 2026

Scattered rain showers and a few storms are currently moving through the area. Scattered to isolated Showers are expected to linger throughout the area for most of the day. Winds will begin to shift to a more NW component this afternoon and evening. Light to calm VRB winds are expected tonight into tomorrow morning. Patchy fog is expected to accompany sites in the early morning hours causing MVFR CIGs. HNB/LEX/RGA have the chance of dropping to IFR with OVC/BKN007 ceilings. Tomorrow morning winds will settle into an almost purely easterly flow.

LMK WATCHES/WARNINGS/ADVISORIES

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