textproduct: Louisville

KEY MESSAGES

* Cooler highs in the mid to upper 60s and isolated low 70s near the TN border are expected today with spotty to scattered showers east of I-75.

* Clouds will slowly mix away later on Thursday, with highs in the 70s.

* Cool morning lows in the 40s and 50s with comfortable highs in the 70s are expected this weekend.

UPDATE

Issued at 837 PM EDT Wed Sep 23 2026

With a low-level inversion, low stratus, and higher low-level moisture in place tonight, chances for drizzle will continue across the region. The weather, POP, and visibility grids were updated in the forecast package to reflect this, as more persistent drizzle could briefly reduce visibilities at times throughout the night.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 224 PM EDT Wed Sep 23 2026

===== This Evening - Thursday Night =====

Clouds have proven stubborn again, meaning our highs will be cooler in the 60s today with a few low 70s closer to the TN border. Drizzle is possible at times this afternoon though everyone west of I-65 should remain dry. Heading east, PoPs slowly increase and reach their greatest values east of I-75 as an inverted trough helps kick off spotty-scattered showers. Rainfall totals should remain light, though should a slow moving shower remain stagnant long enough, isolated areas could receive more than half an inch of rain, although there is a 75% of remaining under 0.5" according to HREF guidance. The best lift remains east of our area so the larger impact to our weather will be the continued fall-like cloudy weather this evening and isolated drizzle in spots.

Tonight, the inverted trough begins to slowly weaken through the night as the influence of a parent high well up into Canada moves further south towards the US. As this happens, subsidence will increase and help to slowly break up the clouds into Thursday. However, this will be a very slow process and everyone should remain overcast overnight with lows in the low 60s an upper 60s. Patchy fog may develop, but the larger concern is for low cloud ceilings Thursday morning.

With increasing subsidence, the main forecast challenge is timing the breaking up of clouds if at all Thursday afternoon. With no large overall pattern shift, trapped moisture below 850 mb will have nowhere to go and rely more on diurnal heating to scour out. That being said, highs have been decreased and should clouds remain stubborn, highs in the 60s and low 70s should be expected. For now, with the uncertainty of how strong the scouring of the clouds will be, a mixture of Consshort and NBM data was used with highs in the low to mid 70s. Regardless by Thursday night, clouds begin to clear east-to-west with coolest lows in the least cloudy communities overnight in the low 50s across the Bluegrass and near 60 in the southwest near Bowling Green, KY.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 224 PM EDT Wed Sep 23 2026

===== Friday - Late Next Week =====

Heading into Friday, at least partly cloudy skies should be expected as the high to our north continues to strengthen. At the same time, an expected surface low should form and rapidly deepen near the NE US. So, as this low strengthens, pre-existing northerly flow will be reinforced from this deepening low. This will keep highs nice and relatively cool in the low to mid 70s from Friday and through Sunday, finishing the weekend. Without a large change in the synoptic pattern, pleasant and sunnier skies will be around as we progress through the weekend.

The pattern shifts by Monday as an Omega blocking pattern emerges and a ridge moves in over KY/IN. As a result, southerly surface flow returns and so do highs in the 80s. Especially by Tuesday/Wednesday, mostly sunny skies will allow temperatures to soar into the 80s, reaching the upper 80s across our south. To close the forecast period, there is a consistent signal in LREF guidance between all the long-term models of a strong trough digging through the central US by late Wednesday into Thursday. Something to keep in mind is that as the trough approaches, storms may return with the added heat by midweek and CWA-wide rain chances. Rainfall totals are too uncertain to predict now, although model solutions are right-skewed towards more than an inch possible across the CWA.

AVIATION /00Z TAFS THROUGH 06Z FRIDAY/

Issued at 807 PM EDT Wed Sep 23 2026

Light NNE flow continues tonight as cigs across the terminals drop from low MVFR to IFR levels. Widespread LIFR cigs are unlikely, with the highest chances near RGA after 08z. With the low-level inversion, low cloud deck, and higher dew points still present, periods of drizzle and reduced visibilities are possible, but confidence remains on the lower end related to the exact timing. Winds will increase and shift to the east Thursday morning, with cigs quickly improving to VFR levels by the afternoon hours.

LMK WATCHES/WARNINGS/ADVISORIES

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