textproduct: Louisville

KEY MESSAGES

* Mainly dry and very cold through Tuesday. Wind chills in the single digits and teens for multiple hours each day.

* Light rain and snow possible Wednesday and Wednesday night.

* Impactful snowfall accumulations possible this weekend, but forecast confidence in amounts and timing remains low.

SHORT TERM /THROUGH TUESDAY/

Issued at 403 AM EST Mon Jan 19 2026

Broad upper level troughing is noted over the eastern 2/3 of the country this morning. Within the cyclonic flow, a mid-level shortwave trough and sfc low are swinging east across the Great Lakes. This weather system is spreading mid-level clouds as far south as the Ohio Valley. These clouds are forecast to lift northeast out of the area by mid-morning.

The associated cold front is pushing southeast through MO and IL early this morning and will pass quickly through southern IN and central KY later this morning. Temperatures are hovering in the mid 20s at the moment, but much colder air is streaming into the Midwest in the wake of the front. A strong arctic high will build southeast over the Plains and MS Valley today, reaching the Mid-South by tonight.

The main sensible weather impacts today will be the cold and wind. Due to that cold arctic high quickly building south over the Plains, the pressure gradient tightens immediately following the cold frontal passage this morning. Gusty westerly winds will add insult to injury today, combining with the cold to drop wind chills into the single digits and teens. In fact, wind chills will briefly drop to near zero in southern Indiana between 7 AM - Noon. Even during the heart of the afternoon, wind chills are forecast to be between 5- 15 degrees (perhaps near 20 in the Lake Cumberland region).

Tonight, the arctic high builds in from the west, allowing winds to diminish but temperatures to plummet. Low temperatures Tuesday morning are forecast to reach 5-11 degrees. A light WSW wind around 5 kts lingering over the northeastern forecast area (southeastern IN and the Bluegrass Region in KY) will cause wind chills to drop below zero early Tuesday morning. Wind chills as cold as -3 to -6 are likely. So after coordination with WFOs ILN and JKL, we issued a Cold Weather Advisory for those portions of Northern KY and the Bluegrass most likely to see minimum wind chills around -5.

High pressure shifts ENE from the TN Valley on Tuesday, and light SW flow will begin to advect some warmer air into the region. Temperatures are forecast to rebound into the upper 20s (NE) to mid 30s (SW) Tuesday afternoon.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/

Issued at 403 AM EST Mon Jan 19 2026

Tuesday Night - Thursday...

Tuesday night into Wednesday, a fast-moving shortwave impulse and weak sfc reflection are forecast to stream from the Plains ENE across the Midwest and Great Lakes. This occurs as strong sfc ridging shifts off the Mid-Atlantic Coast. Much stronger SW low- level flow will advect relatively warm, moist air into the region ahead of a weak cold front. Overall, moisture availability is not great. But a narrow plume of deep moisture should be sufficient for a light rain/snow mix Wednesday into Wednesday night. QPF continues to look quite light with this system, and impacts due to winter weather are not likely at this point. Temperatures should be able to warm into the low to mid 40s on Wednesday before falling back below freezing by early Thursday. High pressure building in from the NW will help provide cool, dry weather on Thursday.

Thursday Night - The Weekend...

Thursday night into the weekend, another significant southward push of arctic air is forecast over the central and eastern US as a ~1050 mb high builds SSE from the Northern Plains. Meanwhile, an upper low is forecast to rotate east over the SW US. A developing southern stream wave with good moisture supply should then interact with the cold airmass to produce a significant winter storm across portions of the southern Plains, Mid-South, Southeast, and perhaps into the Lower OH Valley and Mid-Atlantic.

The frigid, dry airmass to our north will help suppress the southern stream moisture, which could place central KY and southern IN near the northern edge of the heavier QPF footprint. That said, forecast confidence has increased for the precipitation type (snow) with this system. The probability for moderate impacts due to heavy snow exceeds 30% for central and southern KY. Additional details, like timing and QPF/snowfall amounts, need additional time and model runs to come into focus.

AVIATION /06Z TAFS THROUGH 12Z TUESDAY/

Issued at 1237 AM EST Mon Jan 19 2026

SCT-BKN mid-level clouds will continue to stream ENE across the northern terminals early this morning before clearing off to the northeast. Breezy SW winds will feature occasional gusts of 15-20 kts through sunrise. Winds will veer westerly during the mid-morning hours with the passage of a cold front. Winds will increase, with higher gusts of 20-25+ kts likely from the west from mid-morning through mid-afternoon. Winds will diminish once again late in the period as high pressure noses in from the west.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Cold Weather Advisory from 10 PM this evening to 10 AM EST Tuesday for KYZ031>037-039>043-048-049. IN...Cold Weather Advisory from 10 PM this evening to 10 AM EST Tuesday for INZ079.