textproduct: Louisville

KEY MESSAGES

* Record high temperatures in the low to mid 70s today.

* A strong cold front will move through the region tonight. Showers and strong wind gusts of 40+ mph are likely. Localized severe wind gusts of 60+ mph are also possible, mainly between 7 PM this evening and 1 AM EST Monday.

* Temperatures plummet into the 20s and 30s by Monday morning, with colder weather lingering through next week. Wind chills will reach the teens and may briefly drop into the single digits Tuesday morning.

UPDATE

Issued at 947 AM EST Sun Dec 28 2025

Current observations reveal mostly cloudy skies across the region. Temperatures were quite mild with most areas in the low-mid 60s at this hour.

For the remainder of the morning, no significant weather is expected and temperatures will continue to maintain themselves in the low-mid 60s. During the afternoon, southwest surface winds will gradually pick up across the region as the pressure gradient increases and the low-level jet axis to the west moves into the region. Strong warm air advection should allow temperatures to ruse into the low-mid 70s this afternoon despite the cloud cover. Lapse rates will steepen as well which will allow for some additional mixing. So wind gusts of 35-35 mph will be possible as we get into the late afternoon hours.

As we get into the evening hours, a well advertised thin convective line will surge into the region from the west. Just ahead of the line, we will likely see some scattered showers and wind gusts may approach 40 mph outside of showers. This thin convective line will push through our area between 7PM and 1 AM EST.

Taking a look at the latest data, the models continue show somewhat better instability to our west/northwest this afternoon. However, with the setting sun, instability begins to wane very quickly as one gets east of the I-65 corridor this evening. Overall, the convective threat remains rather marginal locally, though with some higher instability off to our north/northwest, have no arguments with the slight risk up across IL/IN. Model soundings do show the develop of a nocturnal low-level inversion just prior to the convective line pushing through. This may keep this line elevated to some extent. However, isolated wind gusts of 50-55 mph to perhaps 60 mph in a few select spots could occur. Lapse rates remain rather marginal (even for cool-season standards), however, low-level SRH may remain elevated enough that some weak QLCS circulations can't be ruled out. However, current indications suggest that the best threat of that would be up across our southwest Indiana counties.

After coordinating with surrounding offices, we have hoisted a Wind Advisory for the entire forecast area for this evening and the overnight period highlighting the wind threat. The remainder of the overnight forecast remains on track at this time.

SHORT TERM /THROUGH MONDAY/

Issued at 308 AM EST Sun Dec 28 2025

A sub-1000 mb sfc low is traversing Kansas early this morning, with a wavy warm front lifting northeast through the Ohio Valley. A digging upper level trough over the Rockies and High Plains will phase with mid-level shortwave energy over the central Plains today. The deeper mid-level trough then rotates east across the Midwest tonight, taking on a neutral tilt. The sfc low will deepen faster as it accelerates northeastward to Lake Huron by late tonight. The intensifying mid-latitude cyclone will feature a strong, fast moving cold front, which is forecast to race across southern IN and central KY 00-06Z this evening.

Well out ahead of the KS low early this morning, sfc winds are veering southerly and beginning to increase to 5-10 kts. Conditions remain largely dry. There have been a few very weak echoes on radar. However, most of the warm advection showers/isolated elevated storms this morning will remain to our northwest across MO/IL/IN on the nose of the LLJ and to the east along the northward lifting warm front.

We will also stay relatively dry through the daytime period as we await the arrival of deeper lift and moisture tied to the cold front. Southwesterly sfc winds will become increasingly breezy this afternoon and evening as the LLJ strengthens to 45-50 kts overhead. Abundant cloud cover, including low clouds, will limit low level mixing. However, strong WAA will aid in temperatures rising into the low to mid 70s this afternoon. This will help steepen lapse rates slightly, and wind gusts of 25-35 mph will be possible in the afternoon. In fact, record high temperatures are forecast today (see Climate section below for the details).

By 21-00Z this evening, southwesterly LLJ winds continue to increase just off the surface as the cold front quickly approaches from the west. Scattered shower activity will be possible just ahead of the front this evening. We could start to see 35-40+ mph gusts mix down to the surface during this time frame.

Most of the rainfall associated with this system will be confined to a thin, shallow convective line (and some trailing stratiform precip) along and behind the cold front. Hi-res CAMs offer decent consistency with timing, and the thin, low-topped QLCS is forecast to push west to east across the area between 7 PM Sun - 1 AM EST Mon. It is this time frame that the wind potential is the highest. 40+ mph gusts appear likely across much of the region, and a Wind Advisory will be considered on Sunday. There will be some potential for 40+ mph gusts to mix to the surface in the 2-3 hours before and after the passage of the main convective line. However, forecast soundings suggest weakly stable lower levels immediately ahead of the line of showers. After coordination with neighbor NWS offices, we will hold off on a Wind Advisory for now. We do plan to issue a Special Weather Statement and continue to highlight the wind gust potential in messaging and graphics.

As for the line itself, the severe convective threat is Marginal. Simply due to the wind energy in place, isolated or localized swaths of damaging 60+ mph winds will be possible. Any weak instability that develops this afternoon over MO/IL is forecast to diminish by the time the QLCS reaches southern IN and central KY after dark. However, with sfc dewpoints in the upper 50s to around 60 late this evening, lapse rates are marginal enough to cause concern given the magnitude of the wind in the lowest 0.5 km. Given the lack of instability, the tornado threat is quite low. However, as we saw on 12/18, the threat for a weak, very narrow tornado is non-zero when the low level shear is so strong.

The other main story with this cold front is the magnitude of the temperature drop early Monday morning. Temperatures will crash from the upper 60s and lower 70s at 7 pm this evening to the mid 20s to lower 30s by 7 am Monday. Conditions are also likely to dry out fairly quickly early Monday morning due to intense cold, dry air advection. Wind chills will drop into the teens Monday morning, so consider a few extra layers if heading out! WNW winds will remain fairly gusty through Monday in the CAA regime. Winds gusting to 25- 35 mph will make for a blustery day.

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/

Issued at 308 AM EST Sun Dec 28 2025

The much colder, drier airmass will linger through the rest of next week. Strong sfc high pressure builds south across the Plains Monday night into Tuesday, which prevents the pressure gradient from weakening too much. Cold WNW breezes will continue into Tuesday, with lows in the mid teens to around 20. This will cause wind chills to briefly drop into the single digits Tuesday morning.

A series of fast-moving clippers look to stream southeast over the Great Lakes and portions of the Ohio Valley Tuesday through Thursday. We'll likely stay mostly dry during this stretch, but brief light snow is possible on New Year's Day. Friday looks dry and cold as well, but small precip chances return next weekend. However, forecast confidence is quite low beyond Friday.

AVIATION /18Z TAFS THROUGH 00Z TUESDAY/

Issued at 1227 PM EST Sun Dec 28 2025

Starting to see some breaks in the clouds early this afternoon which will allow some mixing and bring surface winds up. Expect southwest winds of 15-20kts and gusts of 30-35kts to be possible through the afternoon hours. Cigs are going to hang in the MVFR/VFR range and bounce around a little bit.

This evening, a strong cold front will sweep eastward across the region. A shallow line of convection is expected to accompany the front. Within that small frontal band of convection, winds may gusts to 35-45kts for a short time. Winds will quickly shift to the west/west-northwest behind the front and will remain gusty overnight and into the day on Monday.

CLIMATE

Issued at 308 AM EST Sun Dec 28 2025

Record High Temperatures Likely Today...

Sun, Dec 28th Rec (Yr) | FCST SDF 70 (2021) | 74 LEX 67 (2021) | 72

BWG 72 (2021) | 76

FFT 69 (2021) | 72

LMK WATCHES/WARNINGS/ADVISORIES

KY...Wind Advisory from 6 PM EST /5 PM CST/ this evening to 7 AM EST /6 AM CST/ Monday for KYZ023>043-045>049-053>057- 061>067-070>078-081-082. IN...Wind Advisory from 6 PM EST /5 PM CST/ this evening to 7 AM EST /6 AM CST/ Monday for INZ076>079-083-084-089>092.