textproduct: Louisville

KEY MESSAGES

* Beautiful weather continues for the start of the weekend with highs in the low to mid 80s and dry conditions.

* Strong to severe storms will be possible later Sunday afternoon into late Sunday evening. All severe hazards could be in play, especially along and west of I-65 and north of the WK/BG Parkways.

* A somewhat unsettled pattern is expected through early week with temperatures slightly below normal and off and on shower and storm chances possible, especially across southern KY.

SHORT TERM /THROUGH TONIGHT/

Issued at 307 AM EDT Sat Jun 20 2026

Surface high pressure will continue in the region today and tonight. Temperatures today will warm into the low to mid 80s with dew points in the upper 50s and low 60s. Few light rain showers are possible this afternoon (10-15%) as a weak shortwave moves over southern IN. Chances remain low because of the dry air holding on in the lower levels, therefore a virga scenario could be present. Skies will partly clear today with scattered high to mid level clouds lingering into the night. This along with light winds overnight will allow for nighttime temperatures to cool into the low to mid 60s.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 307 AM EDT Sat Jun 20 2026

Sunday through Monday Night...

Shortwave riding will be in place across the Ohio Valley Sunday morning which will allow the day to start off dry. A substantial MCS should be in progress across portions of central/northern Missouri. During the day, the shortwave ridging will move off to the east and the MCS across Missouri will move eastward into IL/IN. We'll start off the day with sunny skies, but we'll see clouds gradually increase through the day. Despite the clouds, we should see temperatures warm into the 83-88 degree range for highs.

A shortwave trough axis over MO will move eastward into the Ohio Valley Sunday evening. Model solutions have shown a bit more convergence here with the strength of this wave as the GFS/Euro are similar in overall strength. Models show afternoon MLCAPE values surging into the 1300-1700 J/kg range during the peak of the afternoon, but quickly drop off after sunset.

CAM solutions continue to exhibit a bit of spread as we move into the Sunday afternoon/eve period. The overall theme here is that the ongoing MCS over MO will move eastward into IL/WKY during the afternoon and evening. Some scattered convection may also develop across portions of central/eastern KY ahead of this feature. Model soundings from across the region continue show an overlap of deep layer shear values with the moderately unstable atmosphere across our region. The best overlap of shear/instability continues to be across western KY/southern IL and into SW IN and far northern KY. Current SPC day two outlook slightly expanded the slight risk eastward to our border with PAH. The forecast here is conservative due to the convective uncertainty and the potential for instability to wane after sunset with ongoing convection moving into a potentially more hostile environment. Local thinking here is that the slight risk probably will need to be expanded a bit east- northeast with subsequent forecasts into our southern Indiana and portions of northern KY (north of a Hartford/Fort Knox/Lexington line).

Forecast soundings continue to show a favorable environment for wind and a low end tornado threat. With the surface low riding along the I-70 corridor, we could see some localized backed winds across our southern IN counties. Model soundings show 250-350 m2/s2 of ESRH across our northwestern CWA, so a mix of multi-cellular and perhaps low-topped supercells is possible. I say low-topped supercells here because lapse rates in the soundings continue look pretty poor above 500 mb, though low-mid level lapse rates remain decent for organized severe weather. As mentioned above, most models show the thermodynamic profile becoming less favorable as we move into the evening hours with the onset of nocturnal cooling. However, we should have remaining elevated instability to have storms continue eastward into the night.

The lead wave will push east of the region by Monday morning. However, a trailing cold front will likely become more parallel to the zonal flow aloft and stall out across across southern KY or into northern TN. Additional shortwave troughs aloft within the mean flow will pass over the region and this will bring additional rounds of storms across the region. Will be watching the potential for hydro problems that may develop if training convection does develop. Recent rainfall over the past two weeks has been quite impressive across KY and has led to saturated soils which will increase our flood threat. Given expected clouds/precipitation, highs on Monday will be cooler with upper 70s/lower 80s expected. With the front slowly sagging southward and the upper level shortwaves pushing east, we should see drier conditions by Monday night with lows int he upper 50s/lower 60s.

Tuesday - Wednesday Night...

A stretch of drier weather looks likely as we head into the mid-week period. High pressure looks to extend far enough south to keep the aforementioned front well to our south. We'll see below normal temps during this period with highs in the lower 80s and overnight lows in the low 60s.

Thursday - Friday...

Broad upper troughing is expected to hold sway in the late week period. A mid-level trough may bring another round of showers/storms to the region on Thursday with perhaps a return of drier weather by Friday. Below normal temps will be seen here with highs in the lower 80s and overnight lows remaining in the low 60s.

AVIATION /00Z TAFS THROUGH 06Z SUNDAY/

Issued at 1258 AM EDT Sat Jun 20 2026

VFR conditions continue through the TAF forecast period. Light to calm winds will continue through the night, with a light WNW wind tomorrow. BKN and SCT high clouds will linger, and a sub 100 level deck will move in this afternoon. TAFs remain dry however there is a very low chance (10-15%) of a light shower this afternoon. Dry air holding at the surface may even lead to a virga scenario instead.

LMK WATCHES/WARNINGS/ADVISORIES

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