textproduct: Louisville

KEY MESSAGES

* Showers and thunderstorms continue this afternoon and evening, especially along and north of Interstate 64. A few strong to severe storms will be possible, with damaging winds and small hail being the main threats.

* Breezy and mainly dry conditions are expected Thursday, with wind gusts of 25-35 mph expected.

* Above normal temperatures continue through Saturday, with highs in the upper 70s and low-to-mid 80s.

* Rain returns Saturday afternoon with cool, dry and calm weather expected for early next week.

UPDATE

Issued at 851 PM EDT Wed Apr 1 2026

Earlier convection continues to diminish across the region. Main remnants are across Bullitt/Nelson/Spencer counties. We expect this convective activity to completely diminish toward 11 PM EDT. Otherwise, upper trough axis across the Plains will eject northeastward overnight. Heights across the region will build and quasi-stationary boundary over the region will lift back northward toward the I-70 corridor. Mainly dry conditions are expected for the remainder of the overnight period with lows dropping into the low-mid 60s.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 343 PM EDT Wed Apr 1 2026

A weakening cold front extends roughly parallel to the Ohio River across southern IL, IN, and OH this afternoon. Across this frontal zone, there is a strong gradient in temperatures and moisture, with winds also shifting from southwesterly on the warm side of the front to northeasterly on the cool side of the front. While this gradient is just north of our southern Indiana counties, short-range model guidance shows most if not all of our CWA remaining within the warm sector this afternoon and evening, leading to the potential for strong to severe thunderstorms.

Within the warm sector, temperatures are expected to rise into the upper 70s and low 80s this afternoon, with sfc dewpoints progged to remain in the low-to-mid 60s. While the mid- and upper-level temperatures should remain relatively warm, this amount of near-sfc warmth and moisture will be enough for around 1500-2000 J/kg of MLCAPE to develop during the peak heating hours. With instability expected to be plentiful, the main limiting factor for convection this afternoon will be the triggering mechanism which will primarily be associated with the cold front. Storms have already developed across southern IN this morning, and as outflow from these storms combines with the gradual southward push of the cold front, additional storms will be possible closer to the I-64 corridor. Farther south in southern KY, there will be almost as much instability as areas to the north; however, the lack of a well- defined trigger is expected to limit the coverage of storms this afternoon and evening.

Looking at the potential for strong to severe storms, while the instability portion of the parameter space is certainly sufficient for severe convection, wind shear is less robust, with deep-layer shear more akin to a late spring or summertime setup than one in early April. A belt of 40-50 kt of SW flow at 500 mb will gradually weaken later this afternoon and evening, with deep-layer shear generally around 25 kt. These values are more marginal for organized storms, but should be sufficient for a couple strong to severe storms, especially as you go farther to the north and east.

The primary severe threat this afternoon and evening should be gusty, possibly damaging straight-line winds in taller/more robust storms. Since mid-level lapse rates are only expected around 6-6.5 degrees C/km with freezing heights around 10k ft, the thermodynamic environment will be only marginally supportive for severe hail, though several taller storms with small hail will be possible. SPC has included a portion of the CWA in a 2% tornado risk, although there is considerable uncertainty with this as LCLs are expected to remain fairly high (1000-1250 m) and llvl wind shear is expected to be relatively modest. The main time for any strong to severe storms should be between 2 PM and 8 PM EDT. While showers and storms may continue into the late evening hours, especially north of I-64, waning instability and continually weakening shear should curtail the severe storm threat.

Later tonight, another upper-level trough and near-sfc low pressure system will eject from SW to NE across the Plains. As it does so, heights aloft over the Ohio Valley should rise with the remnants of the sfc cold front expected to lift back to the north toward I-70. This should lead to a dry second half of the overnight hours, with a resurgent shot of SW flow expected into Thursday morning.

Tomorrow, the aforementioned upper wave is expected to cut to the northeast across the upper Mississippi Valley and into the Great Lakes. Its associated sfc low will follow a similar path, resulting in the warm sector building back to the north across the Ohio Valley. A stronger low- and mid-level jet will move mainly to the NW of the region; however, flow should be strong enough that wind gusts of 25-35 mph along with scattered 40 mph gusts will be likely as we mix deeper during the late morning and afternoon hours. Temperatures will be unseasonably warm again tomorrow, with highs expected in the low-to-mid 80s.

Thursday night, the cold front will move closer to the region, though the strongest forcing with the system is expected to be lifting to the north of the area. As a result, while a few storms may approach our southern IN counties, the chance for rain and storms Thursday night continues to look less likely, especially east of I-65. Temperatures should again be mild with lows in the mid-to- upper 60s.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 343 PM EDT Wed Apr 1 2026

Friday morning, clouds will linger with spotty showers or storms before mid morning, with current trends indicating rainfall totals will most likely (90%) remain under a tenth of an inch. Near record to record-breaking warm morning lows ranging in the low to mid-60s are expected. An approaching cold front Friday morning will weaken and stall as it moves in from the west, meaning that any showers or storms will be light and short lived. Even though morning showers will end, moisture advection from the Gulf will keep dewpoints near 60. Boosted by a warm front, a chance of showers or storms can't be ruled out. Any severe threat will be limited it seems, even noting the SPC's outlook for Friday with general non-severe storms being possible. Highs will be well above-normal, ranging from the upper 70s to mid 80s. Clouds linger into the overnight with near record warm lows possible Saturday morning ranging in the low to mid 60s.

Saturday morning clouds linger still in anticipation of a stronger cold front that will move in later in the afternoon/evening hours. A couple showers or storms are possible (<10%), though most rain will arrive later in the day. Highs on Saturday will remain warm though western areas may remain cooler than eastern areas if the cold front moves in earlier, limiting daytime heating potential. Temperatures will range in the mid 70s west and low 80s in the east, mainly east of I-65. There's still uncertainty with the timing of the front, being possible it may not bring showers or storms to areas east of I- 65 until late Saturday night. Rainfall totals seem to be near 0.5 - 0.75", though more is possible if there are embedded storms along the front. Eventually, the front will clear eastern areas by early Sunday morning with cooler, drier air moving in place.

With drier air moving in Sunday morning, dewpoints will fall and feel more like Spring instead of Summer. Skies will clear Sunday with highs in the mid to upper 50s. Northwest winds and a surface high pressure will dominate throughout the day and usher in chilly lows into Monday morning, ranging in the low to mid 40s. The high pressure sticks around through early next week as well, as highs remain cooler in the low to mid 60s Monday, then cooling into the upper 50s again Tuesday afternoon. As long as the high pressure remains close by through early next week, dry weather will continue as well.

AVIATION /00Z TAFS THROUGH 06Z FRIDAY/

Issued at 710 PM EDT Wed Apr 1 2026

Widely scattered showers and thunderstorms will be possible for the next hour or two before intabilkity appears to wane. VFR conditions are expected outside of storms. Wind will pick up out of the southwest in the early morning hours Thurdsay before increasing and becoming gusty during the day with gusts up to 25-30 kts. Thunderstorms are possible late in the new TAF period but are currently forecast remain to the west of the area before 00z.

LMK WATCHES/WARNINGS/ADVISORIES

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