textproduct: Louisville

KEY MESSAGES

* Chances for rain showers slowly diminish Saturday as a weak cold front drifts eastward across the area. The highest chances for showers will be over our far eastern counties where the front will be nearly stationary until the evening.

* Episodic bouts of showers/storms are expected to continue through the rest of the weekend and into at least the middle of next week. Localized excessive rainfall may result in flooding in some areas.

SHORT TERM /THROUGH TONIGHT/

Issued at 319 AM EDT Sat May 23 2026

The surface low pressure responsible for our recent showers and storms departs off to the northeast, while its weak cold front slowly drifts eastward across the area today. With considerable moisture still in place (SPC mesoanalysis has a bullseye of PW ~1.7"), showers and a few thunderstorms will be likely (50-70%) ahead of and along the cold front as it moves through the area. The front will become nearly stationary over the eastern portion of the CWA by midday Saturday, so chances for precipitation will continue for those areas through the afternoon.

Rainfall totals will not be as high as they were Friday/Friday night, with the highest amounts located over our eastern counties. HREF probabilities for accumulations over 0.50" over that area ranges from 25-45%, dropping to less than 10% for higher than 1.00" of rainfall. With some clearing possible behind the front, as well as very limited CAA filling in, temperatures will hardly be impacted, with highs in the mid to upper 70s forecast.

As the weak cold front finally departs to the east Saturday evening, conditions will be mostly dry across the area for the evening and early overnight hours. Overnight lows will get into the low 60s, and with dew points also in the low 60s and relatively calm surface winds currently expected, some patchy fog is possible in lower lying areas late Saturday night. The stretch of drier conditions will not last long as the next round of showers begins in the far southwestern portions of the CWA late Saturday night, continuing into Sunday for the rest of the area.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 319 AM EDT Sat May 23 2026

On Sunday, an upper-level low over Ontario moves eastward towards the Great Lakes. Meanwhile, a closed mid-level low begins to develop over Texas. Both systems send mid-level perturbations towards the Ohio Valley, though the overall synoptic scale ascent from these waves is rather marginal. With southerly flow still persisting due to an upper-ridge just off of the east coast in the Atlantic, ample moisture will be in place (LREF PW of ~1.5"). Given the limited synoptic ascent, we only expect diurnally driven showers and a few thunderstorms during the afternoon and evening.

Sunday night into Monday, a frontal boundary sets up near northern Kentucky/southern Indiana and becomes nearly stationary through Tuesday. Additionally, multiple shortwaves from the closed mid-level low in Texas move northeastward along the boundary towards the region. Decent moisture will still be in place along and south of the front (LREF PW of 1.5-1.75"), allowing for multiple rounds of showers and storms to occur. The placement of the boundary will be important since there will be a considerable falloff in rainfall totals to the north of the front. So, we'll continue to monitor trends over the weekend since that would also have an impact on flooding potential for early next week.

Late Tuesday into Wednesday, an amplified upper-level ridge amplifies over the central and SE CONUS. Meanwhile, the closed mid- level low lifts northward towards the central Plains, with the quasi- stationary frontal boundary being pushed northward as well. Shortwaves from the mid-level low continue to flow eastward along the boundary, and with the rich pool of moisture now covering the entire area, more rounds of showers and storms will continue into the latter portion of the workweek. The end of the forecast period on Friday looks a bit more uncertain as a broad and robust upper- level low dives southward towards Quebec and Ontario. This feature would help drive the frontal boundary southward back towards southern Indiana and central Kentucky. Depending on how quickly the front dives southward will determine the coverage of showers and storms for the area.

AVIATION /12Z TAFS THROUGH 18Z SUNDAY/

Issued at 709 AM EDT Sat May 23 2026

Rain showers continue to diminish this morning, though chances will still be elevated for LEX and RGA for most of the day today. Expect cigs to drop to IFR for SDF, HNB, and BWG during the morning, improving to MVFR by the early afternoon, and further improving to VFR by the late afternoon/early evening. Cigs for LEX and HNB will hover around MVFR/low VFR before improving to VFR later today.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Flood Watch until noon EDT today for KYZ030>037-040>043-048- 049. IN...Flood Watch until noon EDT today for INZ077>079-090>092.