This is the NAM model's output only
You're viewing raw atmospheric data from the NAM 3km Nest (North American Mesoscale - High Resolution Nest). This is just one model's interpretation and it may disagree with the other models.
Our AI uses this data (along with other models) to create the final forecast. Don't treat this as the definitive answer.
View the Synthesized Forecast InsteadWintry Mix and Snow to Impact Central and Eastern Kentucky
Kentucky is bracing for a quick-moving weather system this Friday. While Western Kentucky will see plenty of clouds and gusty winds, the real action starts in the afternoon for the rest of the state. Those in Louisville and Lexington should expect a messy transition from light rain to snow during the evening commute.
The heaviest snow is expected in Northeast Kentucky and the Southeast Coalfields, where 1 to 2 inches of accumulation could make roads slick by Friday night. Temperatures will be hovering right around the freezing mark, so even small amounts of snow could create hazardous driving conditions as the sun goes down.
Regional Conditions
PURCHASE
NORTHWEST PENNYRILE
SOUTHWEST PENNYRILE
BARREN RIVER
LOUISVILLE METRO
LINCOLN TRAIL
LAKE CUMBERLAND
NORTHERN KY
BLUEGRASS CORE
BLUEGRASS FOOTHILLS
NORTHEAST KY
SOUTHEAST COALFIELDS
Technical Analyses
To generate the forecast, our AI system analyzed multiple atmospheric layers and variables from the NAM model. Each chart below represents a different aspect of the atmosphere—from the jet stream at 30,000 feet down to surface conditions—providing crucial pieces of the weather puzzle.
The AI model extracted key meteorological features from each analysis, identified patterns and conflicts between different atmospheric levels, and synthesized this information into a coherent forecast. For example, surface temperatures might suggest snow, but upper-level warmth could mean rain instead. The model weighs these factors to determine the most likely outcome based on historical precedent.
Below you'll find detailed breakdowns of each atmospheric analysis that contributed to the forecast, including what the model shows and how it influences Kentucky's weather.
Thermodynamics
How temperature changes with altitude. This determines whether precipitation falls as rain, snow, sleet, or freezing rain based on the vertical temperature profile.
The vertical temperature stack shows a classic winter setup for the eastern two-thirds of the state, with the 0°C isotherm located between the surface and 900mb. In the west, a deep-mixed boundary layer allows for warmer surface temperatures despite cold air aloft.
The freezing line (32°F) is propped over the I-75 corridor by mid-afternoon, slowly sinking southward into the Cumberland Plateau by midnight.
A non-diurnal trend is expected for Central and Eastern Kentucky, where temperatures will flatline or fall during the afternoon as precipitation onset leads to evaporative cooling and dynamic cooling aloft.
Kinematics
Wind patterns and atmospheric energy. Frontal passages, jet stream positioning, and vorticity tell us where and when lift will generate precipitation.
A primary cold front will sweep from west to east between 18Z and 03Z, marked by a sharp wind shift to the northwest and gusts exceeding 35 mph in the Pennyrile and Bluegrass.
A 110kt jet at 250mb provides significant divergence in the left-exit region over Northern and Northeast Kentucky, which correlates with the area of highest expected accumulation.
A compact and vigorous shortwave trough is pivoting through the Ohio Valley, with a maximum vorticity peak of 0.00039 over Southeast Kentucky.
Hydrology
Moisture content and precipitation character. This reveals whether the atmosphere is saturated enough to produce precipitation, and what type to expect (steady vs. bursts).
The column is fully saturated through the DGZ (-12C to -18C) in the East, while Western Kentucky suffers from a dry sub-cloud layer (700-1000mb), introducing a significant Virga risk.
Precipitation will be largely stratiform in nature, though embedded convective elements are possible in the Coalfields where orographic lift is maximized.
Hydrologic concerns are non-existent as total liquid equivalents remain below 0.25 inches statewide.
Winter Physics
Cold-season microphysics. This analyzes how snowflakes form, what type of crystals to expect, and whether roads will be warm enough to prevent accumulation.
A weak 'warm nose' exists near 850mb in the southern Bluegrass (34F), which may lead to rimed snow or a brief rain/sleet mix before the entire column cools below freezing.
Dendritic Growth Zone (DGZ) saturation is favorable in the Northeast, suggesting larger, fluffier flakes (10:1 to 12:1 ratios), while the Southeast will see wetter, compating snow (5:1 to 8:1).
Initial snow will melt on warm road surfaces, but as air temperatures drop below 32°F after sunset, a flash-freeze on untreated surfaces and bridges is a high risk.
Arctic Front Brings Light Snow and Rapid Freeze
Kentucky is bracing for a sharp return to winter as an arctic front pushes through the state. While significant snow totals are not expected for most, a brief burst of snow during the overnight hours will likely coat surfaces, particularly across central and eastern regions.
The bigger story is the temperature crash. By Saturday morning, wind chills will drop into the single digits or even slightly below zero in Northern Kentucky and the Bluegrass. Any moisture left on the roads from earlier rains or melting snow will likely flash freeze, creating slick spots for the morning commute.
Expect clearing skies through the afternoon, but temperatures will remain well below freezing across the northern half of the state. Stay bundled up if you are heading out.
Regional Conditions
PURCHASE
NORTHWEST PENNYRILE
SOUTHWEST PENNYRILE
BARREN RIVER
LOUISVILLE METRO
LINCOLN TRAIL
LAKE CUMBERLAND
NORTHERN KY
BLUEGRASS CORE
BLUEGRASS FOOTHILLS
NORTHEAST KY
SOUTHEAST COALFIELDS
Technical Analyses
To generate the forecast, our AI system analyzed multiple atmospheric layers and variables from the NAM model. Each chart below represents a different aspect of the atmosphere—from the jet stream at 30,000 feet down to surface conditions—providing crucial pieces of the weather puzzle.
The AI model extracted key meteorological features from each analysis, identified patterns and conflicts between different atmospheric levels, and synthesized this information into a coherent forecast. For example, surface temperatures might suggest snow, but upper-level warmth could mean rain instead. The model weighs these factors to determine the most likely outcome based on historical precedent.
Below you'll find detailed breakdowns of each atmospheric analysis that contributed to the forecast, including what the model shows and how it influences Kentucky's weather.
Thermodynamics
How temperature changes with altitude. This determines whether precipitation falls as rain, snow, sleet, or freezing rain based on the vertical temperature profile.
The vertical temperature stack shows a classic arctic air intrusion. Initial profiles are isothermal near freezing, followed by a rapid deepening of the sub-freezing layer to 700mb by 12z.
The arctic front is expected to be entering Northwest Kentucky around 00z, clearing the Southeast Coalfields by 07z.
The trend is aggressively non-diurnal. Surface temperatures will fall from the low 30s to the teens across most of the state between 00z and 12z, with very little recovery during the afternoon due to 850mb temps near -15C.
Kinematics
Wind patterns and atmospheric energy. Frontal passages, jet stream positioning, and vorticity tell us where and when lift will generate precipitation.
A sharp cold front will pass between 00z and 06z, evidenced by a 180-degree wind shift to the northwest and a 10-20 degree temperature drop within three hours of passage.
The state is positioned in the right entrance region of a 110kt upper-level jet, providing sufficient synoptic lift to generate light precipitation despite low moisture availability.
A compact and vigorous shortwave trough is pivoting through the Ohio Valley, with peak vorticity advection occurring between 03z and 09z.
Hydrology
Moisture content and precipitation character. This reveals whether the atmosphere is saturated enough to produce precipitation, and what type to expect (steady vs. bursts).
The atmospheric column is saturated in the lower levels (below 3km) during the frontal passage. However, a significant dry slot follows rapidly, introducing a risk of 'Virga' or evaporating flurries after 09z.
Precipitation will be primarily stratiform light snow with brief convective bursts possible directly along the frontal boundary.
No flooding risk exists; the primary hydrologic concern is the flash-freezing of existing surface moisture.
Winter Physics
Cold-season microphysics. This analyzes how snowflakes form, what type of crystals to expect, and whether roads will be warm enough to prevent accumulation.
No significant 'warm nose' exists at 850mb, ensuring all precipitation remains in frozen form once the surface falls below 32F.
Initial snow will be rimmed/wet near the 32F line, transitioning to high-quality dendrites as the column cools into the prime Dendritic Growth Zone (-12C to -18C).
Rapidly falling temperatures will lead to the crystallization of residual road moisture, leading to a flash freeze scenario, especially on bridges and overpasses.