textproduct: Louisville

KEY MESSAGES

* Dry weather for most today, though there is a chance for an isolated afternoon or evening storm mainly over southern Kentucky.

* Scattered afternoon thunderstorms forecast for Thursday for majority of the area. Storms will be slow moving and capable of torrential rainfall.

* Rain and thunderstorm chances peak Friday into Saturday, especially during the afternoon and evening hours. Slow-moving storms will be capable of locally torrential rainfall, lightning, and gusty winds.

* Outside of storms, heat indices will peak in the 97-103 degree range each afternoon through at least Friday. Minor to moderate heat risk is possible, mainly affecting vulnerable populations sensitive to heat, especially those without cooling/hydration.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 309 AM EDT Wed Jul 15 2026

It is a warm start to the day, with temperatures early this morning in the low to mid 70s across the KY Mesonet network, and SDF currently sitting at 79F. While we'll likely see temps fall a few more degrees by sunrise, this is a sign for temps today to be slightly above normal and expected to reach the lower 90s in many locations, especially north of the WK/BG Pkwys.

Another dry day is in store as a sfc low sits across the Gulf States and sfc high pressure stretches across the midwest. The upper ridge will limit overall storm chances again today, but a lower level inverted trough will be enough forcing to fire off some isolated showers and storms this afternoon across Arkansas and western TN, and some of that activity is forecast to extend as far east as our southwestern CWA and portions of western KY. There is an isolated chance for a t-storm this afternoon for south-central KY, including Bowling Green. Model soundings indicate moderate instability, high PWATs approaching 2 inches, though very weak shear as the wind profiles remain under 30kts through the entire column. Any isolated activity this afternoon will be slow moving storm motion, though will generally have a SE to NW progression. Efficient rain rates will be expected, along with a microburst probability and frequent lightning.

A similar forecast is expected for Thursday, though with more scattered afternoon convection coverage as the upper ridge begins to weaken some. We'll be dealing with near 2 inch PWATs again, along with strong heating to allow moderate destabilization and lingering weak shear to promote slow movers. PoPs for tomorrow vary between 20- 40%, with the Bluegrass area having the best chance of staying dry.

High temps for tomorrow will again be in the upper 80s to lower 90s, though with the sfc dewpoints reaching the mid-70s, we'll likely see heat indices approach 98-102F in many areas, resulting in minor to moderate heat risk - suggesting an increased chance of heat related illness among vulnerable populations.

LONG TERM /FRIDAY THROUGH TUESDAY/

Issued at 309 AM EDT Wed Jul 15 2026

===== Friday - Saturday =====

The highest precip chances of the week arrive Friday, with scattered to numerous showers and storms expected to blossom across the region as a mid-level shortwave begins to pivot across the Ohio Valley. We'll continue to be in a very warm and moist airmass, likely seeing PWATs around or exceeding 2 inches, and sfc dewpoints pushing into the mid 70s. The LREF mean ensemble has a 75F dewpoint Friday afternoon, with an ensemble minimum of 71F, which adds even more confidence in very muggy conditions. Forecast temps are set to peak in the upper 80s to lower 90s, which will yield heat indices around 100F with the dewpoints expected.

Model soundings for Friday afternoon and evening indicate large CAPE profiles due to the strong diurnal heating, along with very weak flow throughout the entire column, potentially less than 20kts. This will result in very weak shear parameters and slow storm motions, leading to pulse convection. Soundings also indicate some dry air aloft to boost DCAPEs near 1000 J/kg. All that said, expect slow-moving, torrential rain rates and microbursts from the strongest storms. The nearly stationary movements could also result in excessive rainfall and localized flooding.

A very similar forecast is expected for Saturday as well, though the forcing could be a bit stronger as the upper trough axis will be sinking south of the Great Lakes and directly across the lower Ohio Valley through the day. We'll see pulse convection light up on radar again Saturday afternoon in a largely unstable and very moist airmass with weak shear.

===== Sunday - Next Week =====

The diurnal precip chances continue for Sunday and into the next week as a weak cold front approaches the lower Ohio Valley as it drops south from the Upper Midwest. This will help influence additional precip chances for Sunday and Monday as the boundary sits to our north across IN/OH.

By Tuesday, another cold front will be approaching the area, bringing additional precip chances, and eventually "cooler" temps by Wednesday.

AVIATION /06Z TAFS THROUGH 12Z THURSDAY/

Issued at 101 AM EDT Wed Jul 15 2026

VFR conditions are ongoing across the region early this morning. Some patchy fog development is possible around or before sunrise, which could cause a temporary vis impact at BWG and LEX this morning. Otherwise, VFR continues today with light winds.

LMK WATCHES/WARNINGS/ADVISORIES

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