textproduct: Louisville

KEY MESSAGES

* Winter Storm Watch has been issued for Saturday morning through Monday morning for major impacts from a significant winter storm. Begin preparing for severe travel disruptions and other infrastructure impacts over the next 24-36 hours.

* A significant winter storm is expected over the weekend. Heavy snow, wintry mix of sleet and freezing rain and cold temperatures are possible, but forecast confidence in specific amounts and detailed timing remains low.

* Very cold temperatures possible through early next week.

SHORT TERM /THROUGH THURSDAY/

Issued at 440 PM EST Wed Jan 21 2026

The NE to SW oriented swath of showers associated with the LLJ will continue to work eastward the rest of the afternoon and evening. Thanks to wet-bulbing, these showers have had a history of producing light to moderate snow showers or a mix of rain/snow with sfc temperatures above freezing. Where the showers have persisted this afternoon, temperatures were in the low/mid 30s but road sfc temperatures had risen above freezing. There could be a few isolated slick spots with any snow showers on untreated surfaces like side roads and parking lots getting slick.

Precipitation should move eastward and out of the CWA by this evening with temperatures holding in the upper 30s to near 40 through the first half of the overnight. A sfc cold front currently located to our west stretching from around Gary, IN through southern IL into the MO Bootheel is expected to move through early tomorrow morning and dropping temperatures into the mid/upper 20s to low 30s by daybreak. Feel the concern for refreeze is low as we will have plenty of time between when precipitation ends this evening and the colder air arrives tomorrow morning.

Sfc high builds in over the Ohio Valley during the day tomorrow. Mostly sunny skies with highs in the upper 30s/low 40s north of the BG/WKY Parkways and low/mid 40s to the south.

LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/

Issued at 440 PM EST Wed Jan 21 2026

Significant Winter Storm likely this Weekend...

Confidence remains high of a significant winter storm bringing moderate to major impacts to central KY and southern IN this weekend. That is why a Winter Storm Watch is in effect from early Saturday morning until Monday morning.

Strong arctic high pressure dropping out of Canada on Friday will start to interact with a surge of Pacific moisture off the coast of the Baja California Peninsula. A closed upper low working on shore over southern CA and the Baja Peninsula will get picked up by the southern stream of the jet. Coupled jet streaks along the southern stream will result in frontogenesis over TX/OK producing widespread wintry precipitation in the form of heavy to moderate snow, sleet and freezing rain Friday night that ultimately spreads north and east across the southern US into the OH and TN Valleys over the weekend.

Model trends continue with the northward shift of the heaviest snow bands but also starts to introduce more wintry mix across southern KY with sleet and even the growing potential for freezing rain along the KY/TN border. While confidence in freezing rain remains on the lower side it is definitely a trend worth noting.

There continues to remain significant temporal and spatial differences between the deterministic models. The GFS continues to be the model furthers south bringing mainly all snow to KY and faster bringing the first of two waves in Saturday morning and a second wave Sunday afternoon. While the ECMWF is further north and showers introducing more of a wintry mix across south central KY but also the highest amounts of snow along and north of the Parkways. The reason for these differences is how both models are handling the closed upper low over the Baja Peninsula and when it finally gets picked up by the southern flow of the upper level jet.

The GFS is slower, keeping the closed low over the Baja and waiting until Saturday night for it to be picked up by the southern jet just south of the Four Corners over northern Mexico, this is why we are seeing two distinct waves of moderate to heavy precipitation as the second wave is the shortwave trough that was once the closed low. By being slower, the closed low blocks the arctic high to the north and keeps the flow over the Ohio Valley more zonal.

The ECMWF has the upper low being absorbed into the southern jet Friday night becoming a shortwave trough. This allows for the northern jet to push the arctic high further south into the central plains , deepening the shortwave trough to the north and creating a more pronounced ridging over the Ohio Valley. This scenario introduces a little more warmer air aloft and creating more wintry mix of sleet and potentially freezing rain into TN and parts of southern KY.

Once models start to ingest data associated with the upper low tomorrow, we should start to see more alignment in solutions and have higher confidence on where the heaviest of snow will fall as well as if we will see any wintry mix. Until then we will continue to focus on overall impacts rather than specific amounts of snow.

What continues to give us high confidence in this being a significant winter storm for our area are the following. The WSSI probability for major impacts continues to grow with a 60-70% across a large portion of central KY including the Louisville and Lexington Metro over the weekend. The probability of exceeding 8 inches is around 60-70% for most of our CWA with a 30 to 50 percent probability of exceeding 12 inches with the swath of heaviest snow falling across the BG/WKY Parkways. Keep in mind until we have a solid handle on the track of this system all snow amounts could drastically change between now and tomorrow. We are also seeing a northward shift in the shift of tails in the ECMWF Extreme Forecast Index showing a 2 across central KY.

The snow will come with cold air as well. Very cold temperatures are possible this weekend and through early next week. Wind chills below 0 are possible Friday night and Saturday morning, with lows in the single digits and teens Saturday morning and highs in the teens and 20s with highs in the low/mid 20s on Sunday. It remains cold as we go into early next week and depending on how much snow is on the ground, temperatures could be colder.

AVIATION /00Z TAFS THROUGH 06Z FRIDAY/

Issued at 645 PM EST Wed Jan 21 2026

For the rest of this evening, the main impact to flight categories should be due to low MVFR/IFR stratus, although patches of mist could result in some MVFR VIS over the next 1-3 hours. A lower confidence impact would be LLWS at LEX and RGA as a 40-45 kt jet remains 2-3k feet AGL for a few more hours. Stratus is expected to clear from NW to SE later tonight as a secondary cold front pushes into the region, and winds should veer around from the southwest to the west-northwest by sunrise Thursday.

For the second half of the current forecast period, VFR conditions are expected with 5-10 kt west-northwest winds during the day on Thursday.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Winter Storm Watch from late Friday night through Monday morning for KYZ023>043-045>049-053>057-061>067-070>078- 081-082. IN...Winter Storm Watch from late Friday night through Monday morning for INZ076>079-083-084-089>092.