textproduct: Louisville

KEY MESSAGES

* Spotty showers move in from the NW with below average highs in the upper 50s and low 60s on Saturday.

* Areas of frost seems likely Sunday morning across the Bluegrass region of central Kentucky. A frost headline will likely be needed for Sunday morning.

* 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 253 PM EDT Fri May 1 2026

This afternoon there is a surface cold front swinging in from the NW. Behind this cold front, temperatures are cool in the mid 50s to the north and mid 60s in the south with wind gusts ranging 20-25 MPH, gusting higher at times. Wind gusts should continue to gust out of the NW for the rest of the day with passing scattered to broken sky cover. After sunset, winds will weaken to near calm overnight with increasing mid to high level cloud cover coming in from our south. How long these clouds linger into Saturday morning will determine how far temperatures tumble. Due to the threat of possible clearing before sunrise, an SPS will be issued for our northern counties for patchy frost Saturday morning. Should clouds clear earlier during the night, expanding the SPS is not out of the question. Otherwise, everyone cools into the mid 30s to low 40s, coolest areas in the northeastern CWA.

Beginning Saturday morning, despite the unusual chilly temperatures, high level clouds will be exiting while lower level clouds from a small low pressure will be moving in near sunrise. As this system moves through, it could spit out a few light rain showers, but with how dry the air will be upon its arrival, very little is possible. Even the 90th percentile only has rainfall amounts near 0.1" or less in latest REFS/HREF ensemble guidance. Otherwise, clouds roll in and break up during the day, eventually clearing by Saturday evening. Highs are cool in the upper 50s and low 60s as well. With cool air in place and with clearing skies, temperatures Saturday night will cool quickly into the 30s and 40s. The main concern is for frost and possible freezes in our far northeastern communities. Generally, these communities have a 20-40% of being below 32 degrees, with area- wide lows ranging in the low 30s to near 40 Sunday morning. For now, frost seems the most likely occurrence (40-80%) considering the low temperatures, calm winds and clear skies for ample radiational cooling.

The good news is that temperatures recover into the mid to upper 60s Sunday afternoon as SW flow begins to return by the afternoon. The parent trough keeping us cool this weekend will begin to lift north and pushing in what could be several shortwaves for early next week. The first shortwave will swing down from the NW late Sunday - early Monday. There is not much moisture to work with ahead of this expected shortwave, though rain showers Sunday evening into Monday morning is still possible (~30%). Showers continue into the morning hours with lows in the upper 40s to low 50s.

LONG TERM /MONDAY THROUGH THURSDAY/

Issued at 253 PM EDT Fri May 1 2026

Moving into the extended forecast period, an upper trough over the Ohio Valley will shift eastward on Sunday with a brief period of surface high pressure building into the region. Sunday looks to be a partly to mostly sunny day with milder temperatures. Highs on the day should warm into the lower 60s over the Bluegrass region with mid-upper 60s in the I-65 corridor and off to the west. Within the northwest flow aloft, a quick moving shortwave trough aloft will slide through the Ohio Valley Sunday night and will bring a chance of overnight showers to the region. Temperatures will be quite a bit warmer with readings in the upper 40s to the lower 50s.

Moving into next week, the flow will become a bit more zonal on Monday. A few weak perturbations may transverse the region and produce a few showers/storms north of the Parkways on Monday. Highs will warm back into the 75-80 degree range with lows in the upper 50s to the lower 60s. The upper level pattern will amplify a bit by Tuesday as more troughing moves into the Plains and we get back into a southwest flow pattern. Better quality moisture plume looks to lift out of the Gulf and into the Mid-MS valley, but the latest guidance shows this plume becoming quite narrow across the Ohio Valley in advance of a southeastward moving cold front. Widespread showers and perhaps a few embedded thunderstorms looks to move through the region beginning Tuesday night and lingering through at least Wednesday night. A look at soundings shows plenty of shear given the stronger flow through the upper trough axis. However, instability across the region is weak, likely due to a manifestation of ongoing convection and cloud cover. Overall, the severe weather threat signal here is pretty weak. AI severe guidance continues to hint at a low end risk of severe, but those AI biases are a bit high especially at longer time ranges. For now, high precipitation chances are expected from Tuesday through early Thursday. After the upper level trough axis moves through along with the surface front, a cooler/drier airmass will filter into the region for the end of the week. Current guidance suggests drier conditions for Thursday. However, weak waves in the upper level flow could result in additional showers by Friday.

Highs Tuesday and Wednesday look to average in the upper 60s/lower 70s. Cooler temps are expected for Thursday/Friday with highs mainly in the 60s and lows in the 40s/50s.

AVIATION /18Z TAFS THROUGH 00Z SUNDAY/

Issued at 112 PM EDT Fri May 1 2026

VFR conditions are ongoing and will continue through Saturday morning. Passing clouds of mostly SCT-BKN near 5 kft are moving through from the NW associated with a dry cold front. Gusts of 20- 25+ kts with the frontal passage will continue this afternoon to near sunset when winds begin to weaken. Winds will shift for everyone out of the N to NE this evening. Overnight, there will be some partial clearing though high level clouds will build in from the south for our Kentucky airports. Winds will be light out of the NE by morning though a second deck of low level clouds will build in from the NW for HNB-SDF by mid-morning. There is potential for HNB to briefly drop to high end MVFR from these Saturday morning clouds but confidence is low and was excluded from their TAF. Otherwise, VFR conditions for a calm Saturday.

LMK WATCHES/WARNINGS/ADVISORIES

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