textproduct: Louisville

KEY MESSAGES

* Strong to severe storms are possible this evening and tonight across southern Indiana and northern Kentucky. A Slight Risk (Level 2/5) issued along and north of I-64. Hail and gusty winds are the primary severe hazards.

* Cooler and mainly dry conditions are expected early next week. * Warmer temperatures and rain chances return by Thursday. Another storm chance is possible Thursday night into Friday.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 352 PM EDT Sun Mar 22 2026

This afternoon, sunny skies and unseasonably warm temperatures are present across the region, with most obs in the mid 80s as of 19Z. Breezy SW winds are also noted in latest obs, with sustained winds of 10-20 mph and gusts of 20-30 mph present. SDF ACARS soundings show a well-mixed layer between the surface and 875 mb, with an inversion around 850 mb and an EML extending through much of the mid- troposphere.

The cold front which will bring our chance for strong storms this evening and cooler air for the first part of the upcoming week is currently located along the I-70 corridor. So far today, this FROPA has been dry across Indiana as the atmosphere remains capped thanks to relatively warm air aloft. However, as the front continues to push south tonight, a mid-level shortwave/vort lobe is expected to swing across the Midwest, and the front should begin to interact with higher dewpoints over the Ohio Valley. This combination of better forcing and moisture should help convection to initiate along the front, with most hi-res guidance showing storms firing over central IN around sunset. These storms should approach our southern Indiana and northern Kentucky counties between sunset and midnight.

As far as the severe potential across our area is concerned, there are a couple limiting factors which makes severe weather a relatively low confidence forecast for tonight. First off, you have the warm temperatures aloft and strong capping which will require additional amounts of forcing from the front to initiate convection. Several hi-res models continue to show convection not firing until behind the front, allowing a cool and stable air mass to undercut storms, eliminating the tornado threat and reducing the damaging wind threat. Second, while storms will initially have a good amount of instability to work with (1000-1500 J/kg MLCAPE), the later into the evening we go, this instability will diminish, leading to less robust updrafts capable of producing large hail and gusty winds. The ingredients for severe weather are most favorable in our area north of I-64, with many areas across southern KY unlikely to receive thunderstorms at all, let alone severe storms.

The one scenario which would increase the overall severe threat would be one like the 12Z NAM-3km in which convection is rooted fairly close to the front. In this case, storms could interact with a well-mixed/higher DCAPE environment and develop a strong cold pool, increasing the damaging wind potential. Overall, it still looks like mainly a hail and damaging wind threat for tonight, with hail being favored initially as convective cores remain discrete and damaging winds becoming dominant if any strong outflow/cold pools can develop. Given the progressive nature of tonight's storms, overall rainfall amounts should generally be less than 0.50" and are not expected to cause flooding.

Outside of the storm threat, winds will veer sharply from southwesterly to northerly across the front, allowing strong CAA to overspread the area later tonight. Where there is more residence time tonight behind the front in the northern CWA, temperatures should be able to fall into the low-to-mid 40s by sunrise Monday. Across southern KY, lows should fall into the upper 40s to near 50.

Tomorrow morning, we should start out with a typical post-frontal low stratus layer over portions of the area, though this should scatter out by midday. Northerly winds should continue through the day, with sustained 10-15 mph winds and gusts to 20 mph expected. Highs should be around 25-30 degrees cooler tomorrow, ranging from the mid 50s to the low 60s. Cool and dry conditions will continue into Monday night, with lows expected in the 30s in most locations.

LONG TERM /TUESDAY THROUGH SUNDAY/

Issued at 352 PM EDT Sun Mar 22 2026

Tuesday - Wednesday Night...

On Tuesday, sfc high pressure is expected to move east across the Appalachians into the mid-Atlantic as the upper ridge over the western US begins to broaden out and heights rise over the Ohio Valley. As the low-level flow regime becomes more easterly and eventually southeasterly, cold advection will subside, allowing temperatures to begin to warm, a trend which should continue through the mid-week period. Dry weather is expected to continue Tuesday into Tuesday night.

By Wednesday morning, the low-level ridge axis should be far enough to the east for return flow to bring moisture back into the region from the deep south. Temperatures are also expected to take a big step upward on Wednesday thanks in part to warm advection, with highs currently forecast to reach the upper 60s and low-to-mid 70s. Even though moisture will be increasing during the day on Wednesday, the current forecast now keeps things dry until Wednesday night. Wednesday night into Thursday morning, a mid-level vort max is expected to slide across the region within the broader NW flow pattern. This should bring the next chance for rain to the region, although exactly where this rain sets up is still uncertain, so forecast PoPs remain relatively low.

Thursday - Next Weekend...

In the wake of the upper shortwave which passes through the region Wednesday night, the upper ridge is expected to flex eastward again on Thursday. Near the surface, low pressure developing over the Plains should help strengthen southerly flow and WAA on Thursday. Thursday will likely be the warmest day of the week, with highs favored to reach the 80s across the area. There is even a 10-15% chance (per NBM probabilities) of reaching 90 degrees across southern and southwestern portions of the CWA.

Another upper-level disturbance is expected to dig into the eastern flank of the upper ridge Thursday night into Friday, which should allow the low pressure over the Plains to sink south as a cold front. There is still a fair amount of spread in the timing and impacts with this system, with medium-range ensembles depicting cold FROPA anywhere from Thursday evening to Friday afternoon. As the front passes, showers and thunderstorms are likely to develop along the front. AI/ML severe convection guidance still features modest probabilities for strong storms with this cold FROPA, and given the "glancing blow" that the stronger winds aloft/greater height falls will deliver, it is not a clear cut setup for strong to severe storms at this time.

Behind the front, temperatures will cool off significantly as we approach next weekend, with high pressure expected to sink into the Ohio Valley by Saturday. Cooler and drier weather is favored through Saturday, with another warming trend favored by next Sunday.

AVIATION /00Z TAFS THROUGH 06Z TUESDAY/

Issued at 802 PM EDT Sun Mar 22 2026

A west to east oriented cold front will drop south and bring showers and thunderstorms through parts of southern Indiana and central Kentucky. The thunderstorm activity is expected to diminish as the line works farther south towards the Ohio River. The front will however bring MVFR ceilings and maybe a few IFR ceilings to area TAF sites. The lowest ceilings will likely be at LEX and RGA. The overnight period is going to remain gusty with 20-25 knot winds veering from the southwest towards the north behind the front. Conditions are expected to quickly improve tomorrow morning from the northwest.

LMK WATCHES/WARNINGS/ADVISORIES

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