textproduct: Louisville

KEY MESSAGES

* Unseasonably warm temperatures are likely through Sunday, with temperatures expected to be 15-25 degrees above normal. Record high temperatures are likely on Sunday.

* A strong cold front is expected to move through the region Sunday night. Showers and strong wind gusts of 40+ mph are likely. Localized severe wind gusts of 60+ mph are also possible, mainly between 7 PM Sunday and 3 AM EST Monday.

* Temperatures plummet into the 30s by Monday morning, with colder weather lingering through the middle of next week. Wind chills will reach the teens and may briefly drop into the single digits Tuesday morning.

UPDATE

Issued at 735 AM EST Sat Dec 27 2025

Expanded the Dense Fog Advisory northward to include Edmonson, Hart, Taylor, Green, Adair, and Russell counties and extended the expiration until 9AM CST / 10AM EST. Fog has been able to form and expand in areas south of the stalled frontal boundary. Expect this boundary to slowly sink farther southward throughout the day, but fog will gradually dissipate by late morning due to diurnal heating. Also refreshed the near term grids. Updated products forthcoming.

Issued at 423 AM EST Sat Dec 27 2025

Decided to issue a Dense Fog Advisory for southern KY, where areas of dense fog are occurring along a weak sfc boundary. More expansive stratus to the north of the boundary is limiting the dense fog potential across most of central KY and southern IN. This appears to be a near-term risk for dense fog, as further expansion of stratus would likely cause any dense fog to dissipate.

SHORT TERM /THROUGH TONIGHT/

Issued at 420 AM EST Sat Dec 27 2025

Quiet weather is anticipated for Saturday, and our stretch of unusually warm weather continues. A weak "cold" front is dipping into south-central KY early this morning. This front is forecast to stall across southern KY today. BKN low clouds linger over the region, with just a couple thin spots in the cloud cover. These gaps appear likely to fill in over the next few hours, and mostly cloudy skies will continue.

Temperatures will settle into the mid 40s (north) to mid 50s (south) in the wake of the weak front. This north to south temperature gradient will persist through the daytime, with highs ranging from the mid/upper 50s north of I-64 to the upper 60s/around 70 in southern KY.

By this evening, lee cyclogenesis will have initiated over the KS high plains ahead of western US troughing. Tonight, a sharp upper level trough digs southeast over the Rockies while beginning to phase with Pacific shortwave energy. Sfc low pressure will move ENE across Kansas, with increasing SW flow WAA downstream into the Mid MS and Lower OH valleys. This will give us a very warm, mainly dry night. There is just a slight chance (20%) for a few warm advection showers early Sunday morning in southern Indiana. Lows in the mid 50s to lower 60s will be common.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 420 AM EST Sat Dec 27 2025

Sunday - Sunday Night...

An upper level trough will continue to dig southeast over the Plains on Sunday before wrapping eastward across the Midwest and Great Lakes Sunday night. A rapidly deepening sfc low is forecast to race northeast from Kansas City to Lake Huron by 12Z Monday, dragging a strong cold front southeast through southern IN and central KY Sunday night. Out ahead of the cold front, conditions will be unusually warm and increasingly windy Sunday into Sunday evening. The daytime period looks relatively dry in the warm sector, with the bulk of the deep lift and moisture still off to the northwest. A 45- 50+ kt SW LLJ develops over the region Sunday afternoon and evening in the warm sector, which will help boost temperatures to record highs for December 28th. Highs are forecast to reach the low to mid 70s, even with persistent cloud cover. However, the clouds will help limit low-level mixing to some degree. This should keep the strongest winds aloft during the daytime hours, but gusts of 25-35 mph look possible Sunday afternoon.

A narrow heavier band of showers, followed by moderate stratiform precipitation, will push through the area late Sunday evening and overnight along and behind the cold front. Most hi-res CAMs bring a low-topped convective band of showers (perhaps no lightning) racing across southern IN and central KY between 7-8 PM Sun and 3 AM EST Mon. While sfc-based instability looks negligible, sfc dewpoints are forecast to be around 60 F just ahead of the line. Given strong forcing along the frontal surface and intense SW winds aloft, confidence is increasing in strong to severe wind gusts Sunday night. Wind gusts of 40-60+ mph appear likely, but damaging 60+ mph wind gusts will be more sporadic and localized in nature.

The primary risk is certainly localized damaging winds, but the tornado threat is non-zero. A lack of instability greatly reduces the tornado threat, but cannot completely rule out a brief, weak tornado given the strength of the LLJ and low-level SRH.

Monday - Friday...

Tremendous cold air advection develops behind the strong cold front early Monday morning. Temperatures are forecast to plunge into the 30s Monday morning, and any lingering post-frontal precip may briefly change to snow before quickly ending. Monday will be cold and blustery, with winds still gusting to 25-30+ mph. Wind chills will be in the teens to 20s all day.

We'll maintain a healthy NW breeze into Tuesday, which will make for a frigid day. Temperatures are forecast to drop into the upper teens and lower 20s by Tuesday morning, and wind chills will briefly bottom out in the single digits before rebounding into the teens/20s for the afternoon.

Chilly, mostly dry weather looks to persist through the rest of next week. Highs should range through the 30s and 40s Wed and Thu, with lows in the 20s. There is a small chance for precipitation late in the week (around Thu time frame), with a reinforcing shot of cold air behind it.

AVIATION /12Z TAFS THROUGH 18Z SUNDAY/

Issued at 635 AM EST Sat Dec 27 2025

A weak sfc boundary is draped across southern KY this morning. Widespread low stratus, including some LIFR/IFR ceilings, is noted over the region this morning. Winds will be light today, and ceilings are forecast to gradually improve through mid-afternoon. A period of VFR looks possible after 21-23Z today, with MVFR stratus forecast to fill back in early Sunday morning. Beyond 12Z Sunday, southerly winds will increase ahead of a strong low pressure system off to the west.

CLIMATE

Issued at 420 AM EST Sat Dec 27 2025

Record High Temperatures Likely Sunday...

Sun, Dec 28th Rec (Yr) | FCST SDF 70 (2021) | 73 LEX 67 (2021) | 72

BWG 72 (2021) | 77

FFT 69 (2021) | 72

LMK WATCHES/WARNINGS/ADVISORIES

KY...Dense Fog Advisory until 9 AM CST this morning for KYZ061-062- 070>076-081-082. Dense Fog Advisory until 10 AM EST /9 AM CST/ this morning for KYZ063>065-077-078. IN...None.