textproduct: Louisville

KEY MESSAGES

* Rain showers and a few thunderstorms possible this evening as a weak cold front approaches the area.

* Wednesday night and Thursday, a strong low pressure system will bring a chance for strong to severe thunderstorms. The greatest risk for severe storms is expected in southern IN. Heavy rainfall and gusty winds (in and out of thunderstorms) are expected.

* Excessive rainfall will be possible across south-central KY on Thursday as the cold front stalls across the region. There is some potential for flash flooding.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

Issued at 421 PM EDT Tue Jun 16 2026

This Afternoon through Tonight...

For most across central KY and southern IN, it is another dry and comfortable afternoon with temperatures in the upper 70s and low 80s and dewpoints in the 50s. A few areas across central KY did see brief rain showers over the past few hours as slightly higher low- level moisture was able to generate tall enough diurnal cu for shallow precipitation cores to develop. To the north and west of the region, a sfc cold front extends from the western shore of Lake Michigan into the mid-Mississippi Valley, with an area of rain showers and clouds located just ahead of the front beginning to push into southern IN at this hour.

For the rest of this afternoon and evening, showers and a few embedded thunderstorms along and just ahead of the front will push toward the area from the west. While there is a risk for severe storms to the north of the region, convection is expected to outrun the pool of sufficient instability as it moves into the area, causing storms to weaken as they approach southern IN. A couple waves of showers and some embedded thunder will move across mainly the northern half of the CWA this evening into the first half of the overnight, with some gusty winds possible as storms collapse over southern IN. By midnight or shortly thereafter, precipitation chances should dwindle with dry conditions expected to return area- wide by early Wednesday morning. Patchy fog will be possible in areas which receive a couple rounds of rain this afternoon and evening and clear out Wednesday morning, with the highest likelihood of fog expected across the Hoosier NF and points west in IN. Otherwise, low temperatures Wednesday morning should reach the upper 50s and low 60s across the area.

Wednesday and Wednesday Night...

Tomorrow, an unseasonably strong upper-level jet streak and mid- level trough is expected to move across the northern Plains and into the lower Great Lakes. Surface response should take place in the form of a deepening area of low pressure, with hi-res progs continuing to show a near- or sub-990 mb sfc low over the lower peninsula of Michigan by early Thursday morning. The rapidly strengthening pressure gradient across the region should lead to warm return flow Wednesday into Wednesday night, sending temperatures up into the mid-to-upper 80s across the area.

Gradient winds will also strengthen out of the SW through the day and into Wednesday night, with BUFKIT momentum transfer progs showing the potential for 30-40 mph wind gusts during the late afternoon hours Wednesday, continuing into early Thursday morning. Nocturnal BL stability should keep the strongest momentum aloft Wednesday night; however, with the LLJ potentially exceeding 60 knots (!), any mixing whatsoever could bring 35-45 mph wind gusts down to the surface. Considered issuing a wind advisory for portions of the CWA for late Wednesday into Thursday morning; however, current most likely wind gusts are marginal for reaching advisory criteria, but will continue to monitor hi-res trends tonight. Long story short, it will be unusually windy outside of showers and storms Wednesday night into Thursday morning.

Integrated Vapor Transport values outside of Climate Forecast System Reanalysis (CFSR) climatology will bring an impressive fetch of moisture into the mid-Mississippi and Ohio Valleys over the next 36 hours, increasing instability across the area by Wednesday evening. A sfc cold front extending to the SW of the strengthening sfc low is expected to fire off strong to severe storms across MO/IL/IN late Wednesday afternoon into Wednesday evening, with storms approaching southern IN by around midnight Thursday morning. As storms approach the area, wind shear will be very strong, especially for mid June, as HREF mean 0-6km shear should be around 50 knots as storms approach the area. Instability, while not overly impressive for late spring/early summer across the area, should be sufficient for strong to severe storms with HREF SBCAPE progs generally between 500-1000 J/kg. The main uncertainty as far as severe weather ingredients are concerned should be forcing, as the main area of mid- and upper- level height falls and the strongest frontal forcing should remain north of the area. However, the unusually potent combination of the other severe ingredients and the robust wind field aloft will mean the any convection of modestly sufficient strength should be able to produce strong winds, particularly along and north of I-64. The tornado potential across the area is more uncertain, as increasingly parallel deep-layer and 0-3 km shear relative to the organized line of convection will make mesovortex development increasingly unlikely as storms approach the Ohio River. The main time window for strong to severe storms continues to be the midnight-sunrise period Thursday morning, with fairly good confidence and consistency in short-range guidance on timing.

LONG TERM /THURSDAY THROUGH TUESDAY/

Issued at 421 PM EDT Tue Jun 16 2026

===== Thursday - Friday =====

Thursday morning, a line of thunderstorms should be ongoing across the CWA, with a general weakening trend expected through the early- to-mid morning hours during the diurnal minimum in instability. Additionally, stronger forcing from the mid- and upper-level jet core is expected to be pulling off to the northeast during the morning hours, although greater than 30 knots of mid-level flow is expected to continue across the area through early afternoon. While there would be a residual damaging wind threat during the morning hours, severe probabilities should be at a minimum during this period, with the cold front continuing to slow down as it pushes toward central and southern KY.

Where this front ends up by peak heating Thursday will be critical for where the greatest rain chances and severe weather potential is Thursday afternoon and evening. Along and south of the front, MLCAPE is expected to increase to 1500-2500 J/kg, with dewpoints in the low 70s and PW values around 1.8" (>90th percentile of climo) representative of a moist, moderately unstable environment. While the wind field near the surface and aloft will weaken from west to east through the daytime on Thursday, there should still be sufficient deep-layer shear for some organized convection. Given a more unidirectional shear profile and the potential for water-loaded storms, would expect damaging winds to be the main severe potential Thursday afternoon and evening. One thing we'll also have to monitor along and south of the front is the potential for training convection, as mid-level flow may orient somewhat perpendicular to the quasi-stationary sfc front, allowing for several rounds of storms to fire along the boundary Thursday afternoon through Friday morning.

Thursday night into Friday morning, a secondary upper trough is expected to move across the Ohio Valley, providing enough of a southward push in the sfc cold front to send the higher moisture and rain chances out of southern KY. Drier weather and cool NW flow should spill into the area on Friday, with clearing skies expected from NW to SE. High temperatures should be below normal, with most areas only reaching the upper 70s and low 80s Friday afternoon.

===== Friday Night - Monday Night =====

For Friday night into Saturday, NW flow aloft and high pressure at the sfc will work across the mid-Mississippi and Ohio Valleys, bringing slightly below normal temperatures and continued dry weather. By the second half of the upcoming weekend, an upper ridge across the southern and southwest CONUS should begin to break down as another upper shortwave slides from Hudson Bay southeast toward the northeast US. As this upper level wave moves to the east, a sfc low in the lee of the Colorado Rockies should eject across the Plains and into the Ohio Valley Sunday into Monday, bringing a chance for showers and thunderstorms back into the forecast across central KY and southern IN. While confidence in specifics remains low this far out, there is some signal in AI/ML for strong or severe convection with this system, so we'll have to watch trends over the next few days. Another period of drier weather is favored behind this system for early next week, with temperatures remaining near or slightly below climatological norms.

AVIATION /00Z TAFS THROUGH 06Z THURSDAY/

Issued at 750 PM EDT Tue Jun 16 2026

VFR conditions will continue through the overnight despite some remnant light rain showers moving over LEX/RGA. Any remaining showers will quickly dissipate overnight as ceilings from periods of BKN cover will remain at VFR heights. HNB might experience fog just before sunrise and will be monitored as morning approaches. S/SW winds will persist through the whole TAF period increasing quickly after sunrise for all airports. S/SW gusts of 15-20 kts in the morning will increase to 25-30 kts by the afternoon from a strong low pressure moving in. PROB30 for storms was included for SDF near 06Z Thursday ahead of this low pressure and we are monitoring an additional LLWS threat for early Thursday morning. Otherwise, VFR conditions with strong gusty winds are expected into Wednesday evening.

LMK WATCHES/WARNINGS/ADVISORIES

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