textproduct: Louisville

KEY MESSAGES

* Scattered showers and thunderstorms will move across the region from west to east this evening (4pm-midnight EST). There is a low chance (5-15%) that the strongest cells produce locally gusty winds or small hail.

* Conditions will turn sharply cooler tonight into tomorrow, with high temperatures likely (90% chance) staying under 50 by Friday.

* There is a low chance for the first flakes of the season Thursday night into Friday mainly over the Bluegrass, but the warm ground should prevent anything from sticking.

MESOSCALE

Issued at 714 PM EST Wed Nov 11 2026

Surface cold front remains well to the west of the forecast area this evening. Scattered convection continues from western KY into southwest IN with the strongest storms remaining within a narrow moisture axis from western into far SW IN. Dewpoints have been relatively slowly to increase over the last three hours. KYMesonet shows dewpoints in the lower 40s over in the Bluegrass with low 50 dewpoints confined to areas west of I-65. Strongest storms right now are across the northern half of Harrison county IN. Another strong storm was over southern Spencer county in Indiana and this will move into Hancock county over the next hour. Mesoscale analysis shows MLCAPE values around 500-900 J/kg across the region along with about 35-40kts of bulk shear. We expect instability to really fall off over the next 1-2 hours. The environment downstream from the ongoing convection is likely to become more hostile with time as the storms encounter less moisture. Nonetheless, showers and storms will be limited to areas west of I-65 through 830 PM EST. The highest risk of severe will be with any core that can remain more isolated from other convection. Here, gusty winds and marginally severe hail will be possible. In areas where multiple updrafts are located, storms will likely have trouble maintaining themselves as they fight over the remaining instability.

DISCUSSION

Issued at 313 PM EST Wed Nov 11 2026

Early Wednesday afternoon, temperatures were in the mid to upper 60s and skies were mostly clear over central Kentucky and southern Indiana. A 1008mb surface low was located over east-central Illinois, with a cold front extending southward through southern Illinois and southeast Missouri. Elevated showers and thunderstorms, which generated severe wind and hail on a gravity wave in the Quad Cities area this morning, are ongoing in the vicinity of this surface low, while still nothing has formed further south along/ahead of the trailing front. SPC mesoanalysis suggests a narrow corridor of over 500 J/kg MLCAPE has developed along the front near/southeast of the St. Louis Metro, and with a few more hours of surface heating the RAP suggests this will increase further to around 1,000 J/kg over southwest Indiana/western Kentucky. In this unstable airmass, REFS expresses high (60-80%) confidence that storms will develop with forcing along the front, while a few additional showers may (30-40% chance) form on the nose of a developing LLJ across northern Kentucky/southern Indiana by around 5-6pm EST.

*** SEVERE WEATHER(?) THIS EVENING ***

Given the aforementioned instability and 30-40 kt deep layer shear, a few of these storms may become organized and produce localized severe weather upstream. However, by the time storms reach our neck of the woods, diurnally driven instability should be waning with the loss of surface heating (sunset is around 5:30 pm EST). In addition, the increase in shear number of showers and storms as the LLJ strengthens deeper into the evening will add abundant rain-cooled air to the environment - limiting the ability of any given cell to gain access to sufficient instability to become severe. Even so, if we should get any isolated cells with unobstructed storm relative inflow (from the southeast, per model hodographs), we could have localized severe wind and hail. Accordingly, SPC maintains a level 1 of 5 (marginal) risk for both hazards across nearly our entire area with a recent upgrade to level 2 (slight) across our west, with the primary time window being between 6 and 9 pm EST.

*** BREEZY AND SHARPLY COOLER TONIGHT ***

The deepening surface low will pull a cold front across our area from the northwest tonight, ushering a cooler airmass into the region. While nocturnal timing will limit the depth of mixing, 3- hour pressure rises of 3-4 mb behind the departing surface low will favor stiff winds out of the northwest - sustained around 15 mph with frequent gusts of 20+ (sporadically >25) mph. These winds will ease only slightly tomorrow morning as the surface pressure gradient weakens but mixing simultaneously deepens. REFS guidance is moderately confident (50-70% chance) that cloud cover sticks around for much of the day tomorrow given wrap around moisture, but below this stratocumulus layer steep low level lapse rates will favor some instability to fuel diurnal showers. This cloud cover and precipitation should confine temperatures to the upper 40s/low 50s throughout the day, but it will also limit cooling overnight into Friday morning - keeping our overnight lows in the mid 30s.

*** FIRST FLAKES OF THE SEASON ON FRIDAY? ***

Friday will be the coolest day of the forecast period with a reinforcing shot of cold air arriving from the north during the morning to bring 850mg temps down to -5 to -6 degC (per REFS mean). Forecast soundings suggest saturation may poke into the DGZ Friday morning across our east to result in a flake or two, but during the day temperatures should be just a little too warm - despite diurnally driven instability once again reaching the DGZ. With any lingering showers over the Bluegrass Friday evening (20% coverage), we may once again see a flake or two mix in, but the probability of anything sticking to pavement to cause impacts is very low.

*** EXTENDED FORECAST PERIOD ***

Winds should finally ease up Friday night, so with any breaks in cloud cover temperatures could take quite the dive. In fact, our forecast features lows in the mid 20s for many locations - locally low 20s in rural valleys. The upper level trough will linger long over the Great Lakes and Northeast, keeping the area seasonably cool (but dry) through early to mid next work week. However, long range models and their respective ensembles generally agree that by late week, upper level ridging will expand into the area from the west to favor a return to milder weather; NBM gives a 60-75% chance high temperatures return to the 60s by next Thursday (11/19).

AVIATION /00Z TAFS THROUGH 06Z FRIDAY/

Issued at 617 PM EST Wed Nov 11 2026

Surface cold front to the west of the region will bring a band of showers and storms into the region this evening. Expect a brief period of heavy rain and MVFR/IFR vsby/cig drops within the storms. Behind the front, we'll see winds veer around to the west and northwest and we'll see some gusts in the 12/06-12Z time frame. Still think we'll see winds ease Thursday morning for a time before picking back up in the afternoon. May have a few showers that develop across central/eastern KY, though mostly VFR conditions are expected.

LMK WATCHES/WARNINGS/ADVISORIES

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