textproduct: Louisville

KEY MESSAGES

* Isolated storms are forecast this afternoon mainly over southern and western KY. Small hail and a cold air funnel cloud are possible in the stronger storms.

* Areas of frost likely Sunday morning across many areas in southern Indiana and central Kentucky. A frost headline is in effect and a few cold spots may hit freezing.

* Weather pattern is expected to become more active next week. Several systems will bring widespread showers and possible thunderstorms to the region Tuesday through late Wednesday.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 220 PM EDT Sat May 2 2026

Watching cells near the Wabash as they scoot southeastward. We may get some stronger cells develop in the widely scattered light showers over western KY this hour. These showers are underneath an upper level low crossing the area. Stronger cores aloft could produce some graupel in storms that move along and south of a line from roughly Lewisport, KY to Campbellsville, KY. Cannot rule out a cold-air funnel cloud with these cells as well.

As mentioned in previous discussion the main story is the cold air coming into place tonight. High pressure will build into the region behind these showers and with skies clearing and light and variable winds, we stand a good chance at frost formation almost areawide. Issued an earlier Frost Advisory for areas that have a higher chance to see low temperatures at or below 36 degrees. Side note: not expecting that cold at the SDF climate site, but more rural sections of that county likely will fall into the mid 30s. NBM came in with temperatures a little cooler in our eastern zones and typical cold spots. Surprisingly cannot even rule out a freeze in some locations. Confidence is not high enough to pull the trigger on that. Frost Advisory headline was generic with lows in the 30s. We may have to watch trends early this evening to see if an upgrade to a Freeze Warning is needed.

Return flow sets up quickly on Sunday as that surface high shifts southeastward. Temperatures should warm up quickly well into the 60s for most sites. That return flow combined with a shortwave coming into the area Sunday night will bring another shot at some rain. It looks to be too quick moving to allow for much in the way of rainfall totals, likely staying well under a quarter inch.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 220 PM EDT Sat May 2 2026

---Monday through Friday---

Lingering rain showers to start the week as the Sunday systems continues to move east out of the area. During the day Monday an upper low will deepening just north of the Great Lakes and will bring additional rain showers to the region. The better chances for precip remain north where SPC has issued a marginal severe outlook. A warm air advection zone will be in place, so temperatures on Monday look to warm back up into the mid-upper 70s.

The low pressure system will continue and develop a cold front that stretches NE from the Great Plains into Ontario. Upper level southwest flow will be favorable for moisture advection from the Gulf ahead of the front, and look to bring in higher QPF. As the frontal boundary approaches the Ohio Valley, widespread rain and thunderstorms will develop ahead and along the front. Widespread rain will move into western KY and southern IN by Tuesday morning and persist through most of the day.

Tuesday night into Wednesday, heavier rain showers and possible embedded thunderstorms will start to develop to the NW. An upper level positively tilted trough digs into the Central Great Plains and amplifies the SW flow over the Ohio Valley. As the cold front moves through the Ohio Valley on Wednesday, additional forcing will increase the probability for severe weather on Wednesday. Model guidance is indicating very little instability throughout the area. However, with the ample amount of shear due to the LLJ and a saturated atmosphere severe weather potential cannot be ruled out. A marginal excessive rainfall outlook has be issued for the region for Tuesday and Wednesday as these rounds of precip could produce 1-2" of rain.

After the trough and cold front passes through, cooler and drier weather can be expected for Thursday as an area of surface high pressure moves over. Maximum temperatures for the later part of the week don't look promising to break the 70s. A weak shortwave disturbance could bring rain chances back into the Ohio Valley Friday.

AVIATION /00Z TAFS THROUGH 06Z MONDAY/

Issued at 740 PM EDT Sat May 2 2026

VFR conditions are ongoing now and will continue for most overnight and into tomorrow. Lingering moisture and calm winds tonight may create fog for BWG, which may bring them down to MVFR, depending on how thick the fog settles in. Otherwise, skies clear for everyone with calm winds until after sunrise. Winds shift in the morning coming out from the SW, gusting 15-25 kts in the afternoon. Mid to high level clouds begin rolling in from the northwest late in the TAF period, but VFR will dominate tomorrow.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Frost Advisory from 3 AM EDT /2 AM CDT/ to 9 AM EDT /8 AM CDT/ Sunday for KYZ023>025-027>043-045>049-053>057-062>067- 074>078-081-082. IN...Frost Advisory from 3 AM EDT /2 AM CDT/ to 9 AM EDT /8 AM CDT/ Sunday for INZ076>079-084-089>092.