textproduct: Louisville

KEY MESSAGES

* Chilly start to the day with upper 30s and low 40s temperatures. Frost possible over the far eastern sheltered areas.

* Dry and milder to end the work week. Then, rounds of showers and and an isolated storm tonight. A few more storms possible on Sunday afternoon.

* Cooler and a return to drier conditions to start next week.

SHORT TERM /THROUGH TONIGHT/

Issued at 255 AM EDT Fri May 8 2026

Another dry day with high pressure sliding east of the area and centering off the mid Atlantic Coast. Look for a chilly start as current temperatures are in the upper 30s and low 40s over most of the area. However, should see a pretty good diurnal range by this afternoon as highs climb into the lower 70s with the help of plenty of sunshine and a steady SSW wind on the western fringes of high pressure. A few gusts up in the 15 to 20 mph range are likely through the afternoon.

Tonight, a shortwave trough and weakening surface boundary will push into the area, bringing scattered to numerous showers across southern Indiana and far northern KY. Farther south across central KY, coverage drops off to the isolated to widely scattered range. Southern KY could end up completely dry. Will still carry a small chance of an isolated storm across southern IN, where meager elevated instability may develop, or just better overall forcing. No surface based CAPE to speak of, so not concerned about any stronger storm threats despite a decent deep layer shear profile. Expected QPF is pretty light for this event with around a tenth to a quarter inch across southern Indiana and lesser amounts farther south.

LONG TERM /SATURDAY THROUGH THURSDAY/

Issued at 255 AM EDT Fri May 8 2026

Saturday - Saturday Night...

Other than perhaps a lingering light rain shower across our far NE CWA on Saturday morning, look for a dry day in the subsident wake of the departing shortwave. Should see plenty of sunshine through the day, and this will allow for temps to warm to around normal values in the mid and upper 70s. Saturday night also looks dry with lows in the 50s across the area.

Sunday - Sunday Night...

Broad upper troughing continues over the eastern CONUS to end the weekend, and we'll watch on Sunday as another shortwave rotates into our region from the central Plains. Meanwhile, a weak surface cold front trailing from an occluded eastern Canada system will also be sliding through our area Sunday morning into the early afternoon. This early frontal passage should limit the potential for much in the way of surface based instability, however NBM probs of at least 500 J/KG of SB Cape range in the 20-40% range during the PM hours. Overall, not really impressive but perhaps a enough for at least some convective development.

The other piece to the puzzle is the shear component, and this remains disjointed and a pretty big limiting factor to anything more than potential pulse storm modes, assuming we do actually get some modest instability in here. The low level jet is non-existent through the afternoon, despite mid to upper level speed shear increasing through the afternoon and evening. The end result will be decent looking 0-6 km shear values (35-50 knots), but the reality is that it will be hard to get an organized updraft with little to no lower level speed shear. Perhaps a stronger pulse storm or two, but with overall instability also on the weak side would be pretty marginal at best.

Monday - Tuesday Afternoon...

The broad trough axis and weak frontal boundary should be through the area on Monday morning, so expecting a return to cooler and dry conditions to start the new work week. Surface high pressure will also be building into the area under NW flow aloft through Tuesday afternoon. Temps will be below normal for this stretch with highs on Monday only expected to be 65 to 70 degrees, and a bit of a warm up on Tuesday into the upper 60s and low 70s. Looks like Tuesday morning could be another chilly morning with lows in the low and mid 40s.

Tuesday Evening - Thursday...

There's been a fairly consistent signal for a good while now that a compact shortwave will quickly travel through the NW flow aloft from the northern Plains into the Great Lakes region Tuesday evening into Tuesday night. This feature will bring an impressive deep layer shear profile with it, and under different circumstances, would be a real problem for our area. Luckily, we get very little time to recover from the anomalously cool and dry cP airmass that had been in place earlier in the week. A look at dew points Tuesday evening and night only has them in the mid to upper 40s, indicating plenty of stability. Forecast soundings for the area back this up, so for now will just advertise scattered showers and perhaps a rumble of thunder thanks to a sliver of elevated instability and good forcing. Most of the coverage would be confined the northern half of the CWA with lesser coverage south based on the current data.

Once the shortwave trough axis and trailing cold front pass clean through on Wednesday, dry conditions will then prevail through Thursday. Temperatures will remain a bit below normal here, mainly in the 50s for lows and 70s for highs.

AVIATION /12Z TAFS THROUGH 18Z SATURDAY/

Issued at 704 AM EDT Fri May 8 2026

Expect VFR conditions to persist throughout most of the forecast as high pressure continues to dominate the region. High clouds will begin to advect overhead this morning into early afternoon while surface winds veer to SW with occasional gusts near 20kt. Overnight, CIGs will drop as a decaying line of showers move into southern IN and northern KY, affecting HNB and SDF. CIGs may briefly drop to MVFR early Saturday morning before returning to VFR.

LMK WATCHES/WARNINGS/ADVISORIES

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