textproduct: Louisville

KEY MESSAGES

* A weakening cold front will bring light showers to southern Indiana and northern Kentucky tonight. A few pops of lightning will be possible, but no severe weather expected.

* A few storms possible on Sunday afternoon, but severe weather is not expected at this time.

* Cooler and a return to drier conditions to start next week.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 339 PM EDT Fri May 8 2026

High pressure has moved east of the region and southwesterly flow is steadily increasing temperatures and moisture in the lower Ohio Valley. Gusty winds will relax as the sun sets this evening.

This evening and tonight, a cold front will move south and a broken line of light showers will accompany it. A 40kt LLJ will help to keep showers along the front, even though the surface boundary will weaken and stall over the Ohio River. Showers will begin to dissipate around dawn as the shortwave aloft continues to the east, taking the lifting mechanisms with it. Central and southern Kentucky will stay dry tonight. QPF over southern Indiana and northern Kentucky will remain light, less than a quarter of an inch. Might see a few pops of lightning over the far northern counties, given a little bit of elevated instability. Though these will quickly cease to just rain through the night.

On Saturday, the stalled frontal boundary will continue to weaken. Flow aloft will become more zonal in the wake of the departed trough, this will help to clear skies. Breezy southwesterly surface winds will continue to increase temperatures to about normal, in the mid 70s. Saturday night, we will see cloud coverage begin to increase ahead of an incoming system. This will prevent radiational cooling, therefore, lows are expected to be in the low to mid 50s.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 339 PM EDT Fri May 8 2026

Sunday - Sunday Night...

A broad upper-level trough will continue to sit over the eastern CONUS as a shortwave moves over the Ohio Valley from the central Plains on Sunday. Additionally, a weak cold front extending from a surface low in Canada slowly drifts southeastward across the region, starting in the morning and departing by the late evening hours. Concern for the potential of strong-to-severe storms continues to be low at this time. While LREF guidance has slightly increased the potential for increased instability Sunday afternoon from previous runs (20-40% for SBCAPE > 500 J/kg), the wind shear profile continues to be disjointed. The cold front will shift our winds to the north, and overall low-level flow is fairly weak (0-1 km shear <10 kt). While mid and upper-level winds will be decent, resulting in 0-6 km shear of 40-50 kt, the weak low-level support should limit the ability for stronger storms to develop. Showers and scattered storms will be possible Sunday afternoon and evening, with the highest probabilities east of I-65 (50-70% chance). Precipitation totals are not currently expected to be high, with LREF guidance depicting 0.15-0.30" of rainfall in our eastern CWA.

Monday - Tuesday Afternoon...

As the cold front fully pushes to the south out of the region, surface high pressure will build in to begin the workweek. Dry and cool temperatures will return. with especially cool overnight conditions Tuesday morning. With clearing skies and relatively calm winds, temperatures could drop into the upper 30s, especially in the eastern half of our area. LREF probabilities of temperatures below 40 are around 35-50% east of I-65, with a 50-60% probability east of I-75. Afternoon temperatures will also be cooler than normal, with highs in the upper 60s/low 70s.

Tuesday Night - Friday...

A robust shortwave and associated surface low will move southeastward from northern Plains towards the Great Lakes Region. While the main core of the system should remain off to our north and east, its cold front should move over our area Tuesday night- Wednesday morning. The wind shear profile with this system is really impressive, however the antecedent cool and dry airmass should limit the potential for stronger storms. As a result, the current forecast only gives a 20-30% chance for showers and isolated storms to develop, with the highest chances in our far northeastern counties. Once the shortwave departs to our east Wednesday, mostly dry and mild weather is expected for the rest of the forecast period. A few weak perturbations Thursday night through Friday could pass through and produce a light shower, though chances for any appreciable rainfall are very low.

AVIATION /00Z TAFS THROUGH 06Z SUNDAY/

Issued at 821 PM EDT Fri May 8 2026

Sfc boundary to our north has been producing light showers and they will start to move into southern IN and northern KY later this evening. Model trend continues to have some of the showers dissipate with the setting sun so they may become more scattered later this evening. CIGs will start to lower to around 4-5K feet with low confidence we get to MVFR at this time. I do have a better chance of showers at HNB but think the threat is lowering for SDF. Outside of that shower threat overnight into early morning, skies will clear out during the morning with VFR conditions.

LMK WATCHES/WARNINGS/ADVISORIES

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