textproduct: Louisville

KEY MESSAGES

* Some light rain is possible in our far SW communities. Otherwise, Monday will feature breezy conditions with wind gusts of 25-30 mph.

* Strong/severe thunderstorms are expected Monday evening and into Tuesday morning. The highest risk of severe weather is in areas west of I-65 and decreases as you head east of the I-65 corridor.

* Another round of strong to severe storms is expected Tuesday evening and into the overnight. Damaging winds and large hail are the main severe threats.

* Temperatures cool Wednesday afternoon and will run below average through next weekend for late April/early May. Mostly dry weather is expected after Wednesday, with a slight chance for light rain on Friday.

SHORT TERM /THROUGH TONIGHT/

Issued at 408 AM EDT Mon Apr 27 2026

===== Monday - Tuesday Morning =====

In the early morning hours today a broken layer of high level clouds is rolling in from the west. A cluster of storms over central/southern MO is approaching our western border counties but is moving into an unfavorable environment, collapsing as they draw closer. We're monitoring how far these storms advance as it seems our western counties, primarily those in the southwestern CWA near Bowling Green, could see some light to moderate rain by sunrise. These showers are not expected to make it beyond I-65, with PoPs generally under 40% for the early morning.

Everyone else though remains dry with clouds around in the morning and morning lows in the low to upper 50s, higher temps in the west from increased cloud cover. Then we await the big weather maker for Monday night. A strengthening shortwave will quickly eject north of Lake Superior Monday afternoon, chasing after the left exit region of an upper level jet. As the shortwave exits, it will kick off a QLCS along a cold front over the plains. These storms though will be moving away from their upper level support from the departing shortwave and be supported by daytime instability, a slowing cold front, and a low level jet through the day as they march eastwards. As the Sun sets, instability decreases and mid to lower level support will be weakening, causing these storms to gradually weaken as they approach from our west. For our CWA the current setup supports discrete cell formation ahead of the main QLCS that could eventually blossom into a secondary line preceding the main event. Despite the expected weakening, the main severe threat from these storms can mix down strong winds from the LLJ overhead. Additionally, a chance of a few tornadoes is possible, especially in our far western border counties where the LLJ will be strongest as the storms roll in.

The timing of these storms is key, along with any preceding supercells/clusters of storms that could weaken the severe potential of the main line. Right now, we think most of Monday morning/afternoon remains dry with a broken-scattered cloud deck at high levels in the morning lowering ahead of incoming storms. Highs Monday afternoon will boost into the upper 70s to mid 80s despite lingering cloud cover. SW wind gusts will increase from daytime mixing with gusts ranging 20-30 MPH. The stronger wind gusts will peak in the afternoon, and will remain gusty until storms roll through. Western counties will be hit first, primarily by clusters undergoing upscale growth forming a preceding line of storms by late afternoon/early evening after 6 PM. Storms will progress eastward, possibly forming two back-to-back lines by late evening along and north of the Bluegrass. As the evening progresses, the severe threat for damaging winds decreases with a loss of daytime heating and the aforementioned loss of upper level support. The greatest severe threat for damaging winds is west of I-65 with a small chance of a tornado more favorable as you head west of Orange County, IN. Later Monday night, these two lines of storms may eventually merge, or the preceding line takes over with a decent moderate rain band following the leading edge of storms. By Monday night, the cold front helping to sweep the storms through will slow and eventually stall out over our central CWA oriented SW-to-NE. The main line of storms will keep moving SE towards our southern communities overnight meaning they take the longest time to clear storms out.

Eventually, storms will be dissipating through the night, becoming a more moderate rain and gusty wind threat into early Tuesday morning. Southern IN counties and points southeast will be drying out early in the morning on Tuesday with light winds veering according to the location of the cold front. Tuesday morning lows remain warm in the upper 50s to low 60s with clouds remaining thick overhead.

LONG TERM /TUESDAY THROUGH SUNDAY/

Issued at 415 AM EDT Mon Apr 27 2026

===Another Round of Storms Tuesday into Tuesday Night===

Tuesday morning through the afternoon, we will see a lull in precip over the region. The cold front will stall over the Ohio River and ample southwesterly flow will keep moisture over central Kentucky. Looking to see dew points in the mid-upper 60s. Will see some sky clearing, which will help temperatures warm into the upper 70s and low 80s.

In the evening, a trough originating over Texas will move over the Tennessee Valley and phase with the broader troughing over the northern CONUS. A surface low pressure system, undergoing cyclogenesis, is expected to move northeast over Kentucky in the overnight hours. Ahead of this low pressure system, the shortwave troughing will bring a source of lift to ample moisture over the region. Storms will initially develop southwest over the mid- Mississippi Valley and push northeast. These storms will be moving into an environment that is favorable for convective activity: 2000- 3000J/kg of MLCAPE, 900 J/kg of DCAPE, 50kts of deep layer shear, and good low and mid level lapse rates. A weak LLJ will result in weak speed shear in the lowest levels, though good curvature is still noted. The largest threats with this round of convection is hail and wind. Currently, the SHIP (hail) parameter is showing values approaching 1.0, therefore large hail will be possible.

Greatest threat area is along and south of the Western/Bluegrass Parkway. Current onset timing is 7pm EDT and lasting through most of the night, though weakening after midnight.

During the overnight hours, the environment will weaken as CAPE decreases. Severe weather is expected to weaken through the night. Though, as the low pressure system tracks over the region, showers and storms are expected to continue through the night. Gusty to damaging winds will be possible through Wednesday morning. The cold front will begin to push southeast through the region on Wednesday and push precip out slowly. CAA will lead to drier and cooler air on Wednesday.

Additionally, rain tonight through Wednesday is 1.5-3.0 inches. With larger totals over the western areas and tapering to the east. This is much needed rainfall over the areas with the worst drought currently. LPMMs show some swaths over our southwestern areas just above 3 inches. With strong storms, brief and minor ponding will be possible, but widespread flooding and flash flooding is not expected.

Bust potential in this case is if we see delayed storms on Monday night. This could delay the environment recovery on Tuesday and lead to weaker convection. Though, forecast trends have shown bust potential is quite low.

===Drier and Cooler Weather to End the Week===

Surface high pressure will build into the region on Thursday. Conditions will remain cool and mostly dry through the weekend. Zonal flow aloft will split the low Ohio Valley between a northern trough and a southern stream system. Both systems may scrape by bringing isolated to scattered chances to the far northern and far southern areas of the region on Friday. Carrying low PoPs in the forecast for Friday. High pressure will follow the Friday system and keep conditions cool and dry.

Looking to see mild high temperatures in the mid 60s for Thursday through the weekend. Low temperatures on Saturday and Sunday morning will be chilly in the mid-upper 30s and touching 40. Some cooler spots may see lows in the mid 30s, where we could see some frost develop.

AVIATION /12Z TAFS THROUGH 18Z TUESDAY/

Issued at 730 AM EDT Mon Apr 27 2026

VFR conditions are ongoing now, but a round of rain will be approaching from the west over the next few hours for HNB -BWG-SDF. This first round of rain will dissipate as it approaches, leaving a PROB30 for -RA/-SHRA from 13-18Z in our western airports. Winds are light for everyone now but by mid morning winds begin gusting from the south ranging 20-30kts. FEW-BKN high level clouds will stick around most of the day despite the initial rain showers. By late afternoon/late Monday night, conditions worsen west-to-east as a more prominent line of storms roll in, dropping ceilings to low end MVFR when they arrive. The strongest wind gusts of the TAF period are expected in this line of storms. Timing is uncertain due to the possibility of preceding storms ahead of the main line. For now, PROB30 was included for all airports for any pop-up storms ahead of the main line that will roll in later Monday evening. Eventually the main line will sweep through with strong wind gusts and heavy downpours. Towards the end of the TAF period, ceilings will continue to be low once storms end overnight.

LMK WATCHES/WARNINGS/ADVISORIES

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