textproduct: Louisville

KEY MESSAGES

* Areas of frost this morning across many areas in southern Indiana and central Kentucky. Frost Advisory in effect until 9am EDT.

* High pressure across the area today, resulting in dry weather and temperatures in the 60s.

* Light showers and perhaps a few elevated storms are possible Sunday night into Monday morning. Gusty southwest winds expected Monday, with temperatures returning to the upper 70s and near 80.

* 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 MONDAY/

Issued at 331 AM EDT Sun May 3 2026

It is a cold and clear morning across the region, with GOES night fog channel showing some patchy valley fog across south-central KY after the round of light rain from yesterday. Most of the area has dropped down into the mid-30s so far, with calm winds making it a favorable morning for widespread frost. The current Frost Advisory runs until 13z later this morning.

For today, the upper trough axis is pushing east of the region, resulting in deep NW flow and brief low-amplitude mid-level ridging. Sfc high pressure is also building across the area, and will influence a drier day. Temps will remain below normal again today, with temps ranging in the 60s.

By tonight, another mid-level shortwave is expected to cross the Ohio Valley, leading to a LLJ overhead that will increase WAA and moisture advection. This forcing will support development of isolated to scattered showers after 00z tonight. Precip coverage will increase through the overnight, with showers and some elevated storms moving from NW to SE across our area. Initially, very dry air from the sfc up to 700mb will result in virga, but gradual top-down saturation will eventually lead to measurable precip being more likely later into the night and into early Monday. The LLJ in place will provide quite strong shear profiles, with large curving hodographs and low level SRH exceeding 300 m2/s2. Fortunately, deep nocturnal inversion will keep a strong stable layer through the overnight, along with considerably high cloud bases given how deep the dry layer will be. SPC highlights our area in general thunder risk.

The bulk of the precip activity will occur before sunrise Monday morning across KY, but then an isolated chance shifts to southern IN for the afternoon. Overall precip amounts will not solve any drought issues, with the HREF 24 hour QPF only with a 35% chance of exceeding 0.15", and a 15-20% of exceeding 0.25". QPF is so light because these showers will be falling out of quite high cloud bases and have a lot fo dry air to get through. In addition to the precip chances, Monday will feature gusty SW winds, with afternoon gusts up to 30-35 mph possible. HREF indicates prob for gusts over 30 mph is more favorable west of I-65, with more than 50%. These SW winds will favor strong WAA, resulting in sfc temps warming back into the upper 70s and near 80 tomorrow.

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/

Issued at 331 AM EDT Sun May 3 2026

===== Monday Night - Wednesday Night ======

We'll be located underneath broad mid-level troughing, with the deeper parent upper low located over Ontario. This system will be supporting an extensive cold front that will stretch from the Great Lakes into the central Plains and over to the Mountain West. We'll be located in the warm sector out ahead of this front, with a healthy WAA plume and moisture transport axis extending from eastern Texas into the Ohio Valley. However, by Monday night, the richer moisture axis will likely shift just north of our area, leading to our precip chances to mainly be north of the Ohio River. Due to the WAA pattern, temps overnight will be quite mild with lows in the upper 50s and low 60s.

By Tuesday morning, the cold front will continue an eastward advancement, which will result in the LLJ and moisture transport axis to move back over our area. This will result in seeing increasing coverage of gusty showers and perhaps some embedded thunderstorms from west to east across the area throughout the day. The front will approach the area by Tuesday night, leading to our highest precip chance for Tuesday night into Wednesday morning as our moisture transport is maximized by the strengthening LLJ just ahead of the front. Showers and thunderstorms will be possible, though still uncertain on any severe potential. Soundings suggest we'll have low-level stability, but a rather high shear environment due to the 40-50kt LLJ. These winds will translate down the sfc during the day too, resulting in wind gusts up to 30 mph possible.

The cold front is expected to push through our area Wednesday morning, ultimately shutting off any low-end severe risk, though will have some showers lingering in the wake of the front through the day. Overall, the NSSL ML severe probs have decreased for Tue/Wed due to low-level stable layer and unfavorable timing of precip during the overnight to limit available instability.

WPC highlights a marginal risk for excessive rainfall for Wednesday due to the prolonged numerous to widespread precip activity across the area. The NBM 48 hour mean ensemble QPF is 1-2 inches of rain, which will actually be a welcome sight given that most of Kentucky is experiencing at least moderate drought conditions. The probability of 48 hour precip exceeding 1 inch is over 70%, though only a 20% chance of exceeding 2 inches.

===== Thursday - Next Weekend =====

A few more showers could be possible on Thursday as another vorticity wing pinwheels around the upper low, but chances are limited to less than 35%. Generally should see a drier trend for Thursday and Friday as the cold front proceeds across the Appalachians. CAA will keep temps in the 60s for Thursday, but should return to near normal on Friday with near 70.

Additional light rain chances will prevail for Friday and into the weekend as we struggle to get clear of the upper troughing and pivoting shortwaves pinwheeling around the low. While it won't be as heavy or widespread, at least an isolated chance lingers for the weekend.

AVIATION /12Z TAFS THROUGH 18Z MONDAY/

Issued at 644 AM EDT Sun May 3 2026

VFR and SKC conditions are across the region this morning, with some patchy fog near BWG. Expect this fog to burn off within an hour or two after the start of the forecast period. Otherwise, expect VFR to continue today. By this evening, increasing cigs will occur, followed by PROB30 chances for -SHRA. Plenty of dry air could delay onset of precip, but eventually expect some light precip to be observed at all terminals but BWG.

LMK WATCHES/WARNINGS/ADVISORIES

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