textproduct: Louisville

KEY MESSAGES

* Isolated to scattered showers and thunderstorms will be possible today. Locally heavy rainfall, gusty winds, and frequent lightning will be the primary weather hazards.

* The late weekend and into early next week will feature drier and hotter conditions with highs warming into the lower 90s.

* An active stretch of weather looks increasingly likely during mid to late next week. Multiple clusters of thunderstorms could move through the region, with strong to severe storms at times and heavy rainfall.

SHORT TERM /THROUGH TONIGHT/

Issued at 309 AM EDT Sat Aug 8 2026

Early this morning, skies were clear to partly cloudy across southern Indiana and central Kentucky. A northward moving outflow boundary combined with a small scale perturbation moving through in the mean flow aloft kicked off a small cluster of storms earlier across southern IN. These storms quickly consumed the available instability and have dissipated. Temperatures across the region were mild this morning with readings in the 70-75 degree range. For the remainder of the overnight, much of the guidance shows dry conditions with lows remaining in the lower 70s through sunrise. We could see some patchy fog in the usual valley and low-lying areas.

For today, the synoptic pattern aloft has not changed much in the last few days. We'll see continued ridging over the western CONUS with a broad, low-amplitude trough axis centered over the Midwest and Great Lakes. This feature will slowly move eastward today and deamplify with time. A weak frontal boundary will drift down toward the region from the north this afternoon and evening. Synoptic scale forcing continues to look rather nebulous across the region today. With diurnal heating, we'll see temperatures warm back into the upper 80s to around 90. We'll see instability develop during the afternoon. However, model proximity soundings continue to show very weak shear across the region (generally 15-20kts). In the absence of focused synoptic scale forcing, scattered convection will be possible across the region this afternoon and this evening. Coverage looks to be 20-40% centered mainly south of the WK/BG Parkways. Given the environment, any storm will be capable of torrential downpours, gusty winds, and frequent lightning.

For tonight, the flow aloft will continue to deamplify as the weak trough axis over the Ohio Valley loses amplitude and slides off to the east. Other than some residual convection from the afternoon, expect that convection to diminish with the setting sun allowing for a quiet overnight period of weather. Lows will generally be in the 69-74 degree range.

LONG TERM /SUNDAY THROUGH FRIDAY/

Issued at 309 AM EDT Sat Aug 8 2026

As we move into the later half of the weekend and into early next week, the overall forecast thinking has not changed substantially. The flow pattern across North America will generally be zonal with a slight ridge over the western CONUS. The storm track will be well to our north with the strongest belt of westerlies running from the northern High Plains through the Great Lakes and into southern New England. A perturbation within the mean flow will move eastward across the Midwest and into the Great Lakes. A cluster of strong to severe storms looks to move through the Midwest and into the southern Great Lakes. At this time, much of this activity looks to stay well north of the LMK CWA. However, there is a slight chance that some southward moving outflow could clip our far northeast areas and spark some showers/storms. Latest LREF members keep PoPs across the region very low (10-20%). The main weather story will be an increasingly warm airmass developing across the region with highs Sunday afternoon warming into the lower 90s. Given that dewpoints will be the low-mid 70s, it will be rather humid with afternoon heat indices warming into the mid-upper 90s. Lows Sunday night will be in the 70-75 degree range. Similar conditions are expected on Monday with afternoon highs in the lower 90s with afternoon heat indices topping out in the 95-100 degree range.

By Tuesday, we'll see the upper level pattern amplify slightly with ridging building across the western CONUS and downstream troughing developing along the eastern US coast. Locally, we'll see heights fall slightly with the flow aloft becoming more northwesterly with time. Most of the day on Tuesday looks to remain dry. However, small scale perturbations will likely cruise through in the mean flow aloft and may bring a cluster of showers/storms to the region by late Tuesday. Highs Tuesday afternoon will be in the lower 90s with overnight lows in the 70-75 degree range.

For the remainder of the workweek, the flow aloft will remain northwesterly. We'll see a few perturbations within the flow move through the region and these could bring episodic bouts of thunderstorms to the region. Given model soundings and a slight increase in wind shear, strong to severe storms could be possible at times along with heavy rainfall. It is still way too early to speculate on storm severity and locations at this time range. Additionally, there continues to be some model spread on just where the storm track will set up. Recent model runs suggests that some stronger ridging may develop across TX and into the southeast which may result in a slight northward shift of the storm track. This could lead to the storm corridor setting up from the Midwest down through the I-70 corridor. The multiple rounds of convection will likely lead to excessive rainfall from the Midwest into the middle/northern portions of the Ohio Valley. Temperatures are expected to be a little cooler with the expected shower/storms around. Highs Wednesday through Friday look to warm into the upper 80s with lows in the upper 60s/lower 70s.

AVIATION /18Z TAFS THROUGH 00Z MONDAY/

Issued at 203 PM EDT Sat Aug 8 2026

VFR conditions are expected through the TAF period. Showers and storms have developed south of BWG and will continue through the afternoon and early evening hours. Given the close proximity, VCTS was included in their TAF through 19z, with a prob30 group of -TSRA through 00Z. If a thunderstorm were to occur, a brief reduction in visibility is possible with a heavier downpour. All other sites should remain dry through the TAF period, with relatively light SSW winds forecast.

LMK WATCHES/WARNINGS/ADVISORIES

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