textproduct: Louisville

KEY MESSAGES

* Early morning cluster of storms will dive south toward south- central KY. Areas east of I-65 expected to remain dry this morning.

* A cold front will be sitting across our area today, and will fire off additional isolated to widely scattered afternoon showers and storms south of the WK/BG Parkways. Best precip chances in our area will be near Lake Cumberland. Severe weather risk remains low.

* Temperatures gradually warm up through the weekend. We expect daytime highs mainly in the upper 80s this weekend with upper 80s and lower 90s expected for much of next week.

MESOSCALE

Issued at 654 AM EDT Thu Aug 27 2026

Patchy dense fog has developed over a portion of southern IN within the last hour, causing vis obs to drop to as low as a quarter mile. Issued a SPS for this patchy fog until 12z, but may need another one if it persists longer than expected. This area received a decent amount of rainfall overnight, and the combination of clearing cloudcover and light winds have supported fog development. Conditions should improve shortly after sunrise.

Issued at 220 AM EDT Thu Aug 27 2026

Early this morning, a cold front is shifting south through the region, with scattered storm clusters firing up from I-65 westward into southern Illinois along the boundary. These storms are feeding off lingering mixed-layer instability, but increasing CIN, meager lapse rates, and weak shear parameters are keeping these storms a bit more unorganized now. Through the rest of the early morning hours, expect this cluster west of I-65 to continue a southward trajectory toward Bowling Green. CAMs have been struggling with this convection, so there is lower confidence than usual on if we'll see this cluster make it to Bowling Green or not. Will continue to monitor over the coming hours, but have adjusted the forecast grids to account for this possibility.

SHORT TERM /THROUGH TONIGHT/

Issued at 220 AM EDT Thu Aug 27 2026

A cold front will be bisecting our area today, with a mostly dry start to the daylight hours. We should see some clearing of clouds through the the morning and early afternoon hours. Sfc high pressure will be east of the area, leading to southerly flow and increased WAA ahead (south) of the sfc boundary. This will lead to decent warming and destabilization again today, with temps peaking in the mid to upper 80s. As the front sluggishly pushes east today, we expect to see isolated to widely scattered storms to redevelop along the boundary across portions of KY, mainly south of the WKY/BG Parkways, with the highest precip chances near Lake Cumberland this afternoon and evening. Model soundings suggest we could have some steeper low level lapse rates, but meager shear will keep any storms from becoming organized. Precip chances end for our area by 00z this evening.

Dry weather takes over for the entire forecast area by tonight due to the post-frontal airmass and sfc high pressure filtering in. Not expecting a strong shift with temps as this front lacks any substantial cooler air behind it, but slightly drier air will help keep our dewpoints lower.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 220 AM EDT Thu Aug 27 2026

===== Friday into the Weekend =====

The upper trough will remain over the eastern US on Friday, but is expected to shift east by Saturday night. The upper pattern becomes a bit more flattened by Sunday, but will begin to see low-amplitude ridging setting up over the Upper Midwest. Dry and sunny weather is expected for Friday and the weekend as sfc high pressure builds across the Ohio Valley. Temperatures range from the mid to upper 80s on Friday, but could warm slightly into the lower 90s by Sunday. Despite this slight uptick in temps, dewpoints look to remain on the more comfortable side and in the 60s each day.

===== Monday through Wednesday =====

We'll continue the warming and dry trend into the first half of next week, with the upper pattern featuring flattened ridging as troughs pass by across southern Canada. Confidence continues to grow on seeing above normal temps next week, but the NBM bias continues to output forecast highs up into the mid 90s next week. The 100-member LREF is not as impressed with temps next week, giving only a 20-30% chance for temps to exceed 90F each afternoon. We'll likely end up seeing most areas hit the upper 80s and low 90s next week, with perhaps our urban islands creeping a few degrees warmer into the mid 90s next week. Heat indices will mostly hover around the upper 90s next week as dewpoints sit in the upper 60s, but we'll begin to see a slightly better moisture fetch by Wednesday to creep dewpoints into the low to mid 70s, leading to some slightly elevated heat indices.

Extended Forecast Discussion...

Looking beyond Wednesday, the long term ensembles and AI Ensemble guidance suggest the upper level pattern will undergo some changes. The upper level ridge that is expected to bring dry/warm weather for much of the week is expected to break down as a series of mid-level waves push across the CONUS. While the details are not overly clear, it does look like that we'll have some passing upper troughs that will drive some cold frontal boundaries through the region. While much of next week will feature above normal temperatures and below normal precipitation, we expect temps to come down a bit to near normal with precipitation going up to normal or slightly above normal.

AVIATION /12Z TAFS THROUGH 18Z FRIDAY/

Issued at 654 AM EDT Thu Aug 27 2026

A MVFR stratus deck has developed over SDF within the last hour, and is expected to continue for a few hours at the start of the forecast period. Additionally, patchy dense fog has impacted HNB with VLIFR vis. Fog will remain a possibility there for a few more hours as well. Otherwise, after the impacts this morning, expect to see VFR conditions for all terminals for the rest of today and tonight. Winds will switch from W to N flow by this evening as a cold front swings through the area. A few isolated SHRA/TSRA will be possible for RGA, but confidence is not high enough to mention in TAF at this time.

LMK WATCHES/WARNINGS/ADVISORIES

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