textproduct: Louisville

KEY MESSAGES

* Brief light snow or flurries late tonight into Thursday morning across southern IN and northern KY. No accumulation to a few tenths of an inch will be possible. * Thursday night into Friday morning, a system will move south of the region and bring mixed precip and snow to southern Kentucky. Confidence is increasing a light accumulations and significant accumulations are not expected.

* Messy weather pattern will continue through mid next week, where light precip will be possible.

UPDATE

Issued at 905 PM EST Wed Dec 3 2025

This evening, we have light radar returns mainly across southern IN, though most if not all of this is not reaching the ground. The low stratus has continued to erode back to the northwest as WAA continues in the sfc-925 mb layer. This warm advection is taking place ahead of a sfc cold front which is currently analyzed from the lower peninsula of MI down into OK. Ahead of this front, temperatures should remain fairly steady tonight given weak southerly flow. As the front begins to sink across the area after midnight, low clouds should increase again from NW to SE. There may be enough low-level moisture for some patchy fog to develop, and given temps at or below freezing across the area, a few slick spots may develop if fog in denser patches of fog.

Just behind the front, there could be a few flurries or light snow showers early Thursday morning along and north of I-64, though latest hi-res guidance has backed off of this somewhat. At most, would expect what was mentioned by the previous forecaster, with a light dusting possible across southern IN.

The forecast is on track at this time. Made minor updates to temperatures and PoPs overnight.

SHORT TERM /THROUGH THURSDAY/

Issued at 249 PM EST Wed Dec 3 2025

Moisture concentrations below 925mb are currently observed in model forecasts and area soundings, sustaining a layer of low stratus clouds over the lower Ohio Valley. At this time, a clearing trend is noted, progressing from the southeast toward the northwest. The eastern and southern portions of the region are anticipated to experience several hours of predominantly clear skies, while the remainder of the area will observe at least partly cloudy conditions. Given the current sky cover and the limited duration of insolation following cloud dissipation, maximum temperatures are expected to remain near or below the freezing point.

Tonight, a shortwave trough will traverse the region, accompanied by an advancing cold front. A 3035 kt LLJ, coupled with a mid and upper-level jet, will create a favorable jet structure to induce atmospheric lift despite minimal available moisture. Consequently, the possibility of flurries exists across the entire area, and light snowfall is forecast for southern Indiana and northern Kentucky during the early morning hours. Impactful accumulation is not anticipated; rather, amounts are expected to range from a trace up to a few tenths of an inch. With light winds and low-level moisture, the development of very patchy freezing fog is possible, although its extent may be limited by the overcast conditions associated with the frontal passage. Overnight low temperatures are forecast to be in the mid-20s.

High pressure will subsequently build in behind the cold front and become centered over the northern Ohio Valley. This pattern will establish a prevailing drier northerly and northwesterly surface flow on Thursday. The low stratus layer will begin to exit the region Thursday morning, from the northwest to the southeast. CAA is expected to prevent high temperatures from rising above freezing across most of the region.

LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/

Issued at 249 PM EST Wed Dec 3 2025

===== Thursday - Friday =====

Flow aloft is expected to become more zonal during this period, introducing a contiguous stream of vorticity across the region. A weak trough will traverse the area on Friday, displacing surface high pressure to the east. This weak trough will introduce a low- pressure system over the Southeastern CONUS. The lower Ohio Valley will reside on the northern periphery of this system, situated within a zone of frontogenesis. Furthermore, a weak LLJ will contribute to lift, interacting with limited low-level moisture. This setup is conducive to producing snowfall across southern and eastern Kentucky from Thursday night into Friday.

With the forecast now within the range of Hi-Res guidance, the expected snowfall accumulation ranges from a Trace to a few tenths of an inch. Isolated areas in the Lake Cumberland region could potentially observe amounts approaching 0.5 inches. The GFS continues to indicate less snowfall, while the Euro presents a more aggressive solution. Examination of the EFI reveals elevated probabilities and a shift-of-tails signal over southern Kentucky. Considering the early stage of the season, this shift-of-tails signal is not a significant concern; however, it warrants continued monitoring, particularly regarding the Friday morning commute.

===== Weekend - Next Week =====

A disorganized, predominantly zonal flow aloft will persist across the region, where minor atmospheric disturbances may traverse the area and yield light precipitation. Despite the unorganized nature of the pattern, it will remain transient, resulting in intermittent light precipitation while largely maintaining dry conditions.

A more significant trough is projected to move through on Monday, increasing the probability of mixed rain and snow showers. Ensemble and deterministic guidance indicate considerable variability in potential outcomes, but this system could bring a few tenths of an inch of snowfall. By the middle of the week, temperatures are expected to moderate to near-normal values, reaching the upper 40s and lower 50s.

AVIATION /00Z TAFS THROUGH 06Z FRIDAY/

Issued at 646 PM EST Wed Dec 3 2025

This afternoon, IFR stratus has cleared out at BWG and RGA, with LEX right on the edge of the stratus at this hour. Over the next few hours, stratus may retreat to the north a bit more, but then it is expected to expand back to the southeast later tonight as a cold front moves across the region. Along the front, IFR ceilings, possibly LIFR, and reduced visibilities from mist are expected. Winds will also veer from SW to NW, though speeds should generally remain less than 6 kt through sunrise Thursday. Confidence in timing of the return of the lower flight categories is medium. Behind the front, a band of light snow will approach HNB/SDF/LEX after 08Z, though confidence is decreasing that snow will reach SDF/LEX.

Behind the cold front, CIGs should very gradually lift Thursday morning from north to south, with winds continuing to veer around to the N/NE. There is a chance that HNB/SDF/LEX could break out of the low stratus by the end of the current TAF period, but confidence in this is still fairly low.

LMK WATCHES/WARNINGS/ADVISORIES

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