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Kentucky AI Weather Engine

Kentucky AI Forecasting Beta

Wed, May 20
Fri, May 22
Forecast For

Thursday, May 21

Updated May 21, 6:52 AM EDT

NWS Alerts Active This Day

Flood Advisory

May 21, 11:14 AM -> May 21, 2:15 PM
Minor Severity

Flood Advisory issued May 21 at 10:14AM CDT until May 21 at 1:15PM CDT by NWS Louisville KY

Confidence
70%

Significant Rain Event to Impact Central & Southern Kentucky

A slow-moving atmospheric disturbance will track across the Ohio Valley on May 21, 2026, bringing widespread rain to the Commonwealth. While Northern Kentucky remains on the drier edge of the system, a corridor of heavy rainfall is expected from the Barren River area through the Bluegrass Core. Flooding concerns are elevated in areas seeing persistent convective training.

Why is this happening?
Technical explanation of the atmospheric setup
Confidence Assessment

High confidence in a rainy day for Southern and Central KY, but significant uncertainty remains regarding the northern extent of the rain and the exact location of the heaviest mesoscale bands.

Get Personalized Forecasts

Choose which region in Kentucky you're interested in and we'll always show you that one first. You can change your selected region by clicking the "Star" icon on any regional forecast.

Purchase Area

Paducah, Murray, Mayfield
Warm and Mostly Dry
Cloudy
71°/ 62°

Northwest Pennyrile

Owensboro, Henderson, Morganfield
Breezy and Overcast
Cloudy
68°/ 60°

Southwest Pennyrile

NUISANCE
Hopkinsville, Madisonville, Princeton
Mild with Afternoon Showers
Rain
72°/ 63°

Barren River

IMPACTFUL
Bowling Green, Glasgow, Franklin
Significant Rain and Soggy Ground
Heavy_Rain
69°/ 64°

Louisville Metro

NUISANCE
Louisville, La Grange, Shepherdsville
Cloudy and Damp Evening
Rain
63°/ 57°

Lincoln Trail

NUISANCE
Elizabethtown, Bardstown, Leitchfield
Persistent Light Rain
Rain
65°/ 58°

Lake Cumberland

IMPACTFUL
Somerset, Columbia, Monticello
Very Wet Day with Heavy Rain
Heavy_Rain
68°/ 63°

Northern Kentucky

Covington, Florence, Independence
Breezy and Mostly Dry
Cloudy
65°/ 51°

Inner Bluegrass

IMPACTFUL
Lexington, Georgetown, Winchester
Potential for Locally Heavy Rain
Heavy_Rain
61°/ 57°

Bluegrass Foothills

IMPACTFUL
Richmond, Danville, Berea
Soggy and Rainy
Rain
64°/ 58°

Northeast Kentucky

NUISANCE
Ashland, Morehead, Grayson
Chilly and Damp
Rain
59°/ 55°

Southeast Kentucky

NUISANCE
Hazard, Pikeville, Harlan
Rainy and Foggy Mountains
Rain
66°/ 61°

Possible Outcomes

Weather forecasting involves uncertainty. Below are two scenarios representing the range of possible outcomes: the "Boom" scenario shows the worst-case/highest-impact result if conditions align unfavorably, while the "Bust" scenario shows the best-case/lowest-impact result if the forecast doesn't materialize as expected.

💥

The 'Boom' Scenario

If the NAM's high-resolution mesoscale banding verifies, a narrow corridor in Central Kentucky could see localized totals exceeding 5 inches, leading to a significant flash flooding emergency.

💨

The 'Bust' Scenario

If dry air entrainment from the high pressure over the Great Lakes is stronger, the rain shield will be suppressed southward, leaving the Bluegrass and Louisville largely dry with totals under 0.25 inches.

Model Disagreements

When models disagree, a call must be made to determine the most likely outcome. This decision is based on a combination of factors including model performance, historical data, and the models general accounting of each climatic region of Kentucky.

The Lexington Deluge Dispute

A massive discrepancy exists regarding rainfall magnitude in Central Kentucky. The NAM is forecasting an extreme 5.7 inch bullseye due to training convective bands, while the GFS/Euro show a much lighter 0.05-0.50 inch range.

NAM
VS
GFS
VS
EURO
Why BLEND Wins

The NAM's 5.7 inch total is likely an over-amplified mesoscale outlier, but the GFS is known for 'smearing' and underestimating convective rain rates. A blend favoring the GEM/NAM placement but with tempered totals is the most realistic path.

Affected Regions
BLUEGRASS COREBLUEGRASS FOOTHILLSLOUISVILLE METRO

The Northern Dry Slot

Models disagree on how far north the measurable precipitation shield will reach. The GFS/NAM keep Northern KY dry, while the Euro/GEM bring light rain across the Ohio River.

GFS
VS
NAM
VS
EURO
Why GFS Wins

High pressure over the Great Lakes is providing a robust source of dry air; GFS typically handles the erosion of the northern edge of precip shields more accurately in these setups.

Affected Regions
NORTHERN KYLOUISVILLE METRO

Technical Analysis

This section provides a deep, physics-based explanation of the weather. Our AI system analyzed multiple atmospheric layers and variables from all available models to synthesize this technical overview.

Below you'll find detailed breakdowns of the atmospheric dynamics that are driving today's forecast, including thermodynamics, kinematics, and hydrology.

Thermodynamics

Stability & Temperatures

How temperature changes with altitude. This determines whether precipitation falls as rain, snow, sleet, or freezing rain based on the vertical temperature profile.

Thermal Profile Overview

The vertical stack is characterized by a deep, moist-adiabatic profile. Thermal profiles are entirely liquid across the state with no freezing layers present below 10,000 feet.

Thermal Boundary

A diffuse thermal boundary is stalled south of the Ohio River, roughly along the Bluegrass Parkway.

Diurnal Trend

Temps will follow a non-diurnal curve in the rain-heavy regions of the Bluegrass, while the Purchase area will see a standard solar-driven curve due to less cloud cover.

Kinematics

Wind & Energy

Wind patterns and atmospheric energy. Frontal passages, jet stream positioning, and vorticity tell us where and when lift will generate precipitation.

Frontal Passage

No clean frontal passage; the event is driven by a stalled boundary and multiple mid-level vorticity pulses.

Jet Stream Support

Strong support from the right-entrance region of a northern stream jet streak provides large-scale lift.

Energy Status

A compact shortwave trough is providing high vorticity (0.0003-0.0009) to Central and Eastern Kentucky.

Hydrology

Moisture & Precipitation

Moisture content and precipitation character. This reveals whether the atmosphere is saturated enough to produce precipitation, and what type to expect (steady vs. bursts).

Saturation Status

The column is fully saturated from the surface to 400mb in the south/east, but significant dry air (virga risk) exists in Northern Kentucky.

Precipitation Character

Precipitation will be primarily stratiform with embedded convective elements that may increase rainfall rates locally.

Flooding Context

The ground is relatively receptive, but totals exceeding 2 inches in short durations would cause flash flooding in urban areas like Lexington or Bowling Green.

Celestial Almanac

Moon Phase

Waxing Crescent

28% Illumination
Moonrise
11:22 AM
Moonset
1:28 AM
Purchase Area
Sunrise
6:43 AM
Sunset
9:01 PM
Civil Dawn
6:13 AM
Civil Dusk
9:31 PM
Northwest Pennyrile
Sunrise
6:35 AM
Sunset
8:57 PM
Civil Dawn
6:05 AM
Civil Dusk
9:27 PM
Southwest Pennyrile
Sunrise
6:39 AM
Sunset
8:56 PM
Civil Dawn
6:09 AM
Civil Dusk
9:26 PM
Barren River
Sunrise
6:35 AM
Sunset
8:52 PM
Civil Dawn
6:05 AM
Civil Dusk
9:22 PM
Louisville Metro
Sunrise
6:28 AM
Sunset
8:53 PM
Civil Dawn
5:58 AM
Civil Dusk
9:23 PM
Lincoln Trail
Sunrise
6:30 AM
Sunset
8:52 PM
Civil Dawn
6:00 AM
Civil Dusk
9:22 PM
Lake Cumberland
Sunrise
6:27 AM
Sunset
8:45 PM
Civil Dawn
5:57 AM
Civil Dusk
9:15 PM
Northern Kentucky
Sunrise
6:21 AM
Sunset
8:50 PM
Civil Dawn
5:51 AM
Civil Dusk
9:21 PM
Inner Bluegrass
Sunrise
6:24 AM
Sunset
8:47 PM
Civil Dawn
5:54 AM
Civil Dusk
9:17 PM
Bluegrass Foothills
Sunrise
6:24 AM
Sunset
8:46 PM
Civil Dawn
5:54 AM
Civil Dusk
9:15 PM
Northeast Kentucky
Sunrise
6:15 AM
Sunset
8:41 PM
Civil Dawn
5:45 AM
Civil Dusk
9:11 PM
Southeast Kentucky
Sunrise
6:21 AM
Sunset
8:40 PM
Civil Dawn
5:51 AM
Civil Dusk
9:10 PM

Dive Deeper Into the Models

This forecast is a synthesis of raw data from the NAM, GFS, ECMWF, and GEM models. These models provide detailed atmospheric analyses including 500mb vorticity, precipitation rates, and more. You can take a look at the raw model data by clicking the links below.