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KEY MESSAGES

* Weather systems will come together over the region tonight and Tuesday morning, bringing a wintry mix and impactful snow accumulations.

* Snow accumulations of 1 to 3 inches are likely across southern Indiana and most of central Kentucky. Brief periods of freezing rain/sleet are possible, and a glaze of ice is possible before changing to snow.

* The heaviest snow accumulations of 2-3+ inches are most likely across southeastern Indiana and portions of north-central Kentucky. Localized, persistent banding of moderate to heavy snowfall could result in narrow swaths of up to 4 inches.

* Impacts to travel are likely Tuesday morning.

SHORT TERM /THROUGH TUESDAY/

Issued at 414 PM EST Mon Dec 1 2025

An upper level trough is over the Upper Midwest and Plains this afternoon, with a potent mid-level vorticity maximum noted over TX/OK. We are already seeing low-level warm, moist air advect northeast over the Lower MS Valley ahead of this wave. Dry low-level air remains in place over KY and southern IN, and sfc high pressure continues to shift across the Northeast. Temperatures have been able to warm into the mid 30s to low 40s under partly to mostly sunny skies this afternoon. However, the dry air at the sfc is especially noteworthy heading into tonight with sfc dewpoints solidly below freezing. Expect fairly steady temps until after sunset with mid and upper clouds spreading in from the west ahead of the upstream trough.

Tonight, the upper level trough will swing ENE over the Lower OH Valley, with potent mid-level vorticity advection providing increasing large scale ascent. In the lower levels, strengthening SW LLJ winds will draw warm, moist air northeast through TN and central KY. Weak low pressure at the sfc will evolve northeast across the Gulf, with an inverted sfc trough setting up through eastern KY/TN.

Strong, deep forcing provided by the above factors, in addition to robust frontogenetical lift, will yield widespread wintry precipitation late this evening through Tuesday morning. The heaviest precipitation is expected late tonight through the early morning hours of Tuesday, when forecast soundings show deep moisture overlapping with the strong lift. PW values will increase into the 0.6-0.9 inch range, certainly above normal for early December. Model soundings and cross sections reveal weak stability in the mid-levels (including the DGZ), above an isothermal layer extending up through about 750 mb. Given the fairly strong fgen forcing expected and sharp mid-level trough rotating in, this environment will likely support heavier banded precipitation. Narrow, heavier bands could easily boost snowfall totals in localized swaths.

Both QPF and snowfall amounts have been increased slightly with this forecast update. The low-level warm advection is still expected to pull a warm nose aloft northeast across central KY tonight, complicating the precipitation type evolution/transition zone. The latest available model guidance remains fairly consistent in bringing that warm nose/p-type transition zone over roughly the southeastern half of the forecast area. In other words, a transition zone consisting of a wintry mix is likely to setup from Morgantown/Bowling Green areas northeast into the Bluegrass Region late this evening and early tonight. Southeast of that line, a plain cold rain is likely for at least a few hours (lasting several hours in the Lake Cumberland region). Northwest of that line, predominantly snow is expected but QPF is relatively lighter further to the northwest. The narrow transition zone from rain to snow will then sweep fairly quickly southeast across all of central KY during the early morning hours tomorrow. Precip will then taper off from west to east as all snow during the mid to late morning hours.

Due to increased QPF and a slightly faster transition to snow as the dominant p-type, the snowfall forecast has been increased slightly. Snow accumulation of 1 to 3 inches is likely across southern IN and most of central KY. Amounts of an inch or less are most likely across southern KY, including the Lake Cumberland region. The heaviest totals of 2-3+ inches are expected across southeastern Indiana, northern KY, and parts of the Bluegrass Region. Some locally enhanced snowfall totals are also possible immediately to the northwest of the evolving p-type transition zone. Localized 4 inch amounts are certainly possible underneath more persistent mesoscale banding.

Based on the updated forecast, the Winter Weather Advisory was expanded slightly to the southeast to include Bowling Green, Campbellsville, and Richmond. Regardless of the exact snowfall accumulation in any one spot, slick and hazardous travel will be possible Tuesday morning. Temperatures are forecast to dip into the upper 20s to right around 32 degrees early Tuesday morning. Even in south-central KY where snow amounts will be lighter, slick spots will be likely (especially elevated surfaces) during the Tue morning commute. Light snow could also end as freezing drizzle during the mid to late morning hours Tue as drier air advects into the region aloft. Skies will remain mostly cloudy through Tue afternoon, with highs only in the low to mid 30s.

LONG TERM /TUESDAY NIGHT THROUGH MONDAY/

Issued at 414 PM EST Mon Dec 1 2025

A cold high pressure system builds into the region for the midweek time frame. Wednesday morning, in particular, will be quite cold with lows in the mid teens to around 20 degrees. Temperatures should rebound into the mid 30s to low 40s Wednesday afternoon under mostly sunny skies.

Yet another cold front is forecast to drop through the area Wednesday night and early Thursday, bringing another quick shot of cold air. Look for lows in the 20s and highs in the 30s. This front looks to pass through dry, with only an increase in cloud cover. Another sfc high quickly builds east across the Ohio Valley late in the week as another weak low pressure system sets up across the Gulf Coast. A southern stream wave could bring us some light precip on Friday, but most of the moisture could also pass to our south. Forecast confidence is fairly low Friday and beyond.

AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 709 PM EST Mon Dec 1 2025

The forecast remains on track as a system approaches the region tonight. Between 4-7z all area TAF site ceilings are expected to fall into IFR levels, and snow showers will drop visibilities into IFR levels.

Currently, SDF and HNB are expected to see snow for most of the event. LEX could see short period of a mix as rain begins falling before changing to all snow around 6-8z. RGA expect all rain until changing to snow around 8-9z. BWG can expect all rain until changing to snow around 7-8z.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Winter Weather Advisory until 10 AM EST /9 AM CST/ Tuesday for KYZ023>043-045>049-053>057-061>067-070>072. IN...Winter Weather Advisory until 10 AM EST /9 AM CST/ Tuesday for INZ076>079-083-084-089>092.