textproduct: Louisville

KEY MESSAGES

* Dense river valley fog is expected overnight and into the morning. Patchy fog may form outside of valleys as well. * Daily highs will remain in the low to mid 70s through the weekend as stubborn ridging keeps us dry.

* Beautiful weather is expected into early next week. Dry weather will continue through at least next Tuesday.

DISCUSSION

Issued at 248 PM EDT Wed Oct 21 2026

===== Pleasant Afternoons with Chilly Mornings and Valley Fog =====

Weather conditions continue to be warm, sunny, and pleasant across the whole area. Temperatures are all in the low 70s with all but calm winds. The center of a ridge axis is parked directly overhead causing the nice weather. Despite the ongoing mixing, temperatures will tumble to the saturation point across multiple areas in the CWA overnight with lows in the low 40s and upper 30s. In the deepest decoupled valleys overnight, dense fog is expected to form along with patchy frost as isolated spots could reach the low to mid 30s. The frost potential will remain confined to our easternmost valleys. Fog will form in low lying areas across the CWA, meaning another SPS will be issued for patchy dense fog, though confidence is a little low for a Dense Fog Advisory. Highest fog chances are near 40%, with under 20% chances in areas further west.

Despite the chilly and potentially foggy morning, the CWA will mix out quite nicely Thursday afternoon. A very weak cold front will move in from the NW from a departing low pressure in Canada. May not see or feel much of a difference as this passes by. At most, this front will knock our highs down by a degree or two compared to today. Sunny skies will linger and the threat for more valley fog will persist Thursday night into Friday morning.

===== Stagnant, Slow Pattern Change Until Next Week =====

By the weekend, the ridging at the surface will be reinforced with ridging at higher levels, indicating little changes in our weather. Means that highs in the low to mid 70s will continue along with the daily valley fog threat each morning. Mid level ridging slowly weakens along with the surface high pressure by early next week. Long range trends are painting a picture of an approaching trough weakening and lifting north as it tries to push into the antecedent dry air mass we'll still have in place by Tuesday-Wednesday. PoPs remain under 10% which means rainfall is highly unlikely. We may return into a wet/busy pattern by Halloween weekend, although confidence this far out is really low.

AVIATION /00Z TAFS THROUGH 06Z FRIDAY/

Issued at 703 PM EDT Wed Oct 21 2026

Calm to light NNE winds will continue through Thursday morning. By Thursday afternoon, winds will increase to 5-8kts. Skies will remain clear through most of the TAF period. IFR-MVFR VIS due to fog is possible at RGA/HNB/BWG in the 8-13Z hours, similar to previous nights.

LMK WATCHES/WARNINGS/ADVISORIES

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