textproduct: Louisville

KEY MESSAGES

* Seasonably mild weather will continue through tomorrow. Many locations will climb back into the 80s Wednesday through Saturday.

* Overnight low temperatures may fall into the upper 30s in low- lying rural areas tonight, but the probability of frost is low.

* Mild-moderate drought conditions, worst over southern Kentucky, will worsen this week as dry weather prevails. The next (40-50%) chance for beneficial rainfall will arrive Sunday.

DISCUSSION

Issued at 255 PM EDT Mon Oct 5 2026

*** MILD THROUGH TOMORROW, PATCHY FROST(?) TONIGHT ***

Seasonably mild conditions continue over central Kentucky and southern Indiana today as high pressure to our north maintains cool, northerly breezes. At 245pm EDT, temperatures were in the low 70s, and dewpoints, brought down by deep mixing into a dry layer above 900mb, were in the upper 30s to mid 40s. This dry airmass and lack of any clouds will favor efficient radiational losses overnight, though some uncertainty exists in winds as high pressure settles over the Appalachians, leaving a slight gradient across our area. In sheltered valleys, particularly across the Bluegrass area where winds will be lighter closer to the high pressure center, temperatures may (HREF probabilities are 15-30%) fall into the upper 30s tonight. However, any frost would be extremely isolated, as indicated by NBM's <3% probabilities for temperatures less than 37 degF.

*** SLIGHTLY WARMER, REMAINING DRY INTO SATURDAY ***

As the surface high shifts east across the Mid-Atlantic, the pressure gradient will weaken across the area tomorrow favoring light and variable winds, while sunny skies allow temperatures to climb into the mid to upper 70s (warmest south). Return flow out of the southwest will develop tomorrow night into Wednesday, advecting a slightly warmer airmass into the region. Given mixing up to around 850mb, HREF mean 850mb temps around 15 degC suggests highs will climb into the lower to mid 80s (warmest west), however this deep mixing will also bring dry air down to the surface (min RH values 25- 35%) - keeping heat indices cooler than actual air temperatures.

A decaying cool front will sink south into central/southern Indiana on Thursday, with surface high pressure once again shifting from the Midwest to Appalachians in its wake. Meanwhile, the warm and dry airmass is likely to linger over our area into the weekend with raw and calibrated guidance maintaining highs in the upper 70s to low 80s through Saturday (around 5-7 degrees above "normal").

*** TROPICAL REMNANTS TO BRING BENEFICIAL RAIN(?) BY SUNDAY ***

There remains considerable uncertainty surrounding the evolution and track of a disturbance over the southwestern Gulf. NHC suggests there is a 60% (80%) chance of development into a Tropical Cyclone over the next 2 (7) days, however member low locations from both the GEFS and EPS ensembles exhibit considerable spread in its eventual track with some members bringing it northward into our neck of the woods and others shunting it across the Southeast US. If the low tracks near/through the local area, the deep Gulf Moisture associated with this system suggests we'd see a hefty rain event - perhaps ending the developing drought. However, if it passes to the east or west, the weekend would likely remain dry afterall. At this time, our forecast features a 40-50% chance of measurable rain, while NBM chances for more than 2 inches range from 10% north of I- 64 to 25% over central/southern Kentucky.

AVIATION /18Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 126 PM EDT Mon Oct 5 2026

VFR conditions will prevail as high pressure shifts from the Midwest today into the Appalachians tomorrow. Consequently, northeast winds around 8-13 kt this afternoon will ease this evening and veer to an easterly direction tomorrow morning. We should hold onto enough of a wind overnight to prevent fog formation, though it can't be completely ruled out at RGA and HNB (5-10% chance).

LMK WATCHES/WARNINGS/ADVISORIES

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