textproduct: Louisville

KEY MESSAGES

* Today through Tuesday, temperatures are expected to warm into the mid 80s to low 90s. Some daily max temperature records could be challenged. * Showers and/or thunderstorms could arrive for some Monday evening, especially for our northwestern counties.

* A line of strong to severe storms are expected to move through along a cold front on Tuesday evening. All hazards will be possible. The line will weaken as it move southeast over the region.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 337 PM EDT Sun May 17 2026

The nice but very warm weather we've been experiencing today is thanks to the upper ridge over the eastern CONUS further building over our region. Even though we will have mostly clear skies tonight, steady southerly winds and dew points around 60 will only allow temperatures tonight to fall into the upper 60s, with some places only dropping into the low 70s.

For Monday, the upper ridge will continue to amplify as a robust upper-level trough digs over the central and western CONUS. A few perturbations from the deep south will move northward towards the region while an MCS from what will be this evening's severe weather event over the Plains treks eastward towards us. In addition, moisture aloft will be carried northward over our region, with PW values near or above 1.5" (~95th percentile climatologically) and dew points lifting into the mid 60s. The forcing from the perturbations should be enough for some pop up showers and thunderstorms to develop over our far northwestern counties, with a couple of stronger storms possible. The current timing of the MCS would allow it to weaken just to our north, with the mid/upper jet lifting it northward our of our area. With mostly dry and sunny conditions expected during the day, temperatures will again be in the upper 80s, with some places exceeding 90. The continued push of southerly flow Monday night will only allow temperatures to drop into the upper 60s/low 70s, which could threaten some record warm minimums.

LONG TERM /TUESDAY THROUGH SUNDAY/

Issued at 337 PM EDT Sun May 17 2026

===Tuesday: Strong to Severe Storms Ahead of a Cold Front===

Tuesday morning, broad ridging will remain over a warm, moist environment. This will allow temperatures to remain above normal in the upper 80s and brushing 90 in some spots.

A shortwave moving out of Texas may move over the region, which will bring scattered showers and storms over the region mid morning and into the afternoon. With ample mixing and warming, we will see steep lapse rates in the afternoon and increased uninhibited CAPE. Looking to see about 2000J/kg of SBCAPE. About 25-30kts of shear will allow a few storms a become more organized or congeal, but not expecting impressive storm structures. Could see some gusty winds, small- medium sized hail, and lightning. Additionally, PWATs of 1.7-1.9 inches will bring periods of heavy rain. As a result, brief ponding will be possible.

With this daytime convective activity, it may dampen the severe threat in the evening. Though, the environment may recover quickly, given the very warm and moisture airmass. The cold front will approach from the northwest in the evening and a line of showers and storms will accompany it. Depending on timing, will determine if we are still surface based. Around 0Z timing, we will see better environment for all hazards. A 30kt LLJ will be moving northeast over the region and provide increased low-level shear. We will also still see higher SBCAPE. The later the line arrives, the environment will weaken. Additionally, as the line of storms pushes east, will likely begin to outrun the best forcing, and it will dissipate. Greatest severe threat will be over the northwestern 2/3rds of the area.

===Return to Near Normal Temperatures===

The cold front will exit the region by Wednesday morning, bringing a return to near normal temperatures. The cold front will stall over the Tennessee Valley. A messy southwesterly flow pattern will bring daily chances for showers and storms through the weekend. No one day will be a washout, but scattered chances are to be expected. Late week and into the weekend, we will see temperatures begin to increase to above normal values.

AVIATION /18Z TAFS THROUGH 00Z TUESDAY/

Issued at 142 PM EDT Sun May 17 2026

VFR conditions will persist through the TAF period. A few mid-level clouds may build in this afternoon, but will not impact flight categories. Current southerly wind gusts across the area will decrease after sunset, increasing again midday Monday.

LMK WATCHES/WARNINGS/ADVISORIES

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