textproduct: Louisville

KEY MESSAGES

* A cold front will bring scattered showers during the morning hours today. There is a low probability (10%) of thunderstorms. Severe weather is not expected.

* Much warmer weather arrives this weekend, with near record highs possible Sunday and Monday (low 90s).

* Scattered showers and thunderstorms are possible Saturday. Additional showers and thunderstorms appear likely next Tuesday.

SHORT TERM /THROUGH THURSDAY/

Issued at 304 AM EDT Wed May 13 2026

A weak cold front associated with a low pressure system over the Great Lakes will push through the Ohio Valley today. A band of rain showers will move in from the NW this morning and diminish as it moves through the Bluegrass region. Overall confidence is low in thunderstorm potential because of the timing of the showers and lack of overall instability to develop any storms. The far eastern part of the CWA has a 10 - 20% chance of thunder in the afternoon as there is a marginal amount of instability (400-600 J/kg), however the front would need to slow for the ingredients to align. QPF values are minimal with localized areas only up to 0.15". Winds will increase this afternoon with gusts 20-25 mph out of the WNW. High temperatures today will warm into the mid to upper 70s across the forecast area.

The front will exit out of eastern KY by this evening, and surface high pressure will build back in behind it. Skies will clear for the overnight over hours with light NNW winds, cooling temps to the low to mid 40s. Surface high pressure will keep Thursday dry with clear skies, and afternoon temperatures warming into the mid 70s.

LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/

Issued at 304 AM EDT Wed May 13 2026

Thursday Night - Friday...

A narrow ridge axis will traverse the region Thursday night. Skies look to start off mostly clear, though we may see increasing clouds by dawn Friday ahead of a mid-level shortwave trough moving over the Mid-MS Valley. Winds will be light and variable or calm overnight with the sfc high overhead and then shifting to the east. It will be another cool night with lows in the 40s. The Bluegrass Region will see the lowest temps in the low 40s. Lows in the mid/upper 40s look more likely along and west of I-65.

The mid-level shortwave trough will quickly move over the Lower OH Valley on Friday in the left exit region of a southern CONUS jet streak. The low-level airmass remains quite cool and dry to start off Friday, though we do see steady warm, moist advection throughout the day. It appears upstream rain showers will diminish as they attempt to push in from the west, and LREF members remain split on precip chances (ENS members are notably wetter). Think there is enough of a signal for at least a slight chance mention of isolated showers, though the QPF is relatively light and low confidence. In general, Friday looks mostly pleasant with afternoon temps warming into the mid/upper 70s.

Friday Night - Saturday...

Low-level ridging amplifies off the Southeast US coast heading into the weekend. Southwesterly flow will continue to funnel warm, moist air into the region. This signals a pretty significant pattern shift that will linger through the end of this forecast period. A consensus of medium range guidance pushes sfc dewpoints into the low to mid 60s by Saturday, and this increased low-level moisture contributes to LREF mean SBCAPE of around 1500 J/kg.

This will also mean warmer temperatures, with Saturday morning lows only falling into the upper 50s and lower 60s in most places. Temperatures should then rise into the mid 80s Saturday afternoon, though the potential for convection complicates the temperature forecast. Another shortwave disturbance will likely interact with the warm, moist airmass, yielding scattered showers and thunderstorms. Deep-layer flow is weak, which reduces the threat for organized severe convection. However, we could see some stronger storms capable of heavy downpours, gusty winds, and lightning.

Sunday - Tuesday...

After the Saturday disturbance passes by, the weather likely dries out for Sunday. We will see rising heights aloft over the eastern CONUS downstream of a digging western CONUS trough. Sfc low pressure spins up east of the Rockies and eventually develops northeast across the central Plains and Upper Midwest heading into early next week. A warm front will lift well north of the region by Sunday and Sunday night. This places us within a broad warm sector with deep SW flow and a strengthening mid/upper level ridge over the SE CONUS.

The above pattern will keep us dry and very warm on Sunday, with afternoon temperatures soaring into the upper 80s. Some locations could touch 90. Sfc low pressure lifts into the Upper Midwest by Monday, with the trailing cold front still well off to the west. We should stay dry into Monday morning, but we could see isolated to scattered convection approach the area by Monday evening as the LLJ and moisture transport axis translate eastward. The sfc cold front is forecast to sink southeast across the Mid-MS and Lower OH Valleys Monday night into Tuesday. Pooled moisture along this boundary is likely to send PW values above 1.5 inches, exceeding the climatological 95th percentile. Numerous showers and thunderstorms will be possible Tuesday, which could include some potential for heavy rainfall and strong thunderstorms.

AVIATION /06Z TAFS THROUGH 12Z THURSDAY/

Issued at 128 AM EDT Wed May 13 2026

A band of rain showers are currently moving ESE through south central IL and IN ahead of a cold front. These scattered rain showers will move through central KY and the Bluegrass region this morning, with rain expected at SDF by 08z and to LEX by 11z. Mid to low level clouds will also move into all sites with the boundary. Ceilings are expected to stay VFR around 8k ft, although showers could briefly drop ceilings right around 5k ft. As the front pushes through the region, winds will take a shift from SW to NW with wind gusts 20-25kts into the afternoon hours. Skies will mostly clear by this evening with lingering FEW250, and completely clear out around 06z Thur.

LMK WATCHES/WARNINGS/ADVISORIES

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