textproduct: Louisville

KEY MESSAGES

* Stubborn cloud cover will persist overnight with 30-40% of rain showers possible east of I-75 Wednesday afternoon.

* Temperatures will remain cooler tomorrow in the 60s-70s, though should cloud cover break up, low 80s are possible along the TN border.

* Crisp/cool mornings are expected for Friday/Saturday mornings where lows may bottom out in the lower-mid 40s across the Bluegrass region.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

Issued at 236 PM EDT Tue Sep 22 2026

===== This Evening - Wednesday Night =====

Persistent moist low level flow from the NE at the surface to just above the 925mb layer has really socked moisture in over KY. Looking upstream of this NE flow, all other areas are also socked into low level stratus clouds with temperatures in the low to mid 60s. While this cloud deck is slowly eroding away in far SE KY, short-range modeling has continued to suggest a rapid dissipation of this cloud deck. This has yet to be realized and this simulated dissipation is delayed each model update. As a result, highs have been dropped greatly, especially north of the Ohio and across the Bluegrass and these communities should expect 60s for the rest of the day. Continued cloud cover should be reinforced by higher level clouds from remnant overnight storms helping to reduce mixing within the low to mid levels of the atmosphere. Across south-central and southern KY, with enough thinning, temperatures will be in the low to mid 70s, with isolated upper 70s in Clinton and Cumberland Counties as they've managed to clear in some places.

Otherwise, continued NE flow from a parent high pressure over southern Canada will keep us locked into a cool weather pattern. Overnight, any breaks in cloud cover will be short lived and an inverted trough builds by the early morning. Lows won't be much different from today's highs in the low 60s to upper 50s, coolest areas north of the Ohio. As the inverted trough strengthens, overcast skies linger with showers forming by late morning in east KY. These will slowly drift counter-clockwise moving west into our CWA by the afternoon. Lift may be enhanced by a passing mid level disturbance as well. However, any rainfall will be light to moderate in nature and would be an off-and-on type of rain, with those in the Bluegrass having the best chance of rainfall tomorrow (30-40%). Rainfall totals will be light, generally a tenth of an inch or less, with isolated communities east of I-75 having a 40% chance of seeing around a quarter of an inch according to the latest HREF guidance. The real problem is that since CAMs are struggling with cloud cover today, they probably will tomorrow as cool NE flow will dominate again, at least in the first half of the day. We've dropped highs tomorrow as a result, but may need to be dropped further should cloud cover prove to be stubborn like this afternoon. Regardless, highs will be cooler in the upper 60s across our northern IN counties and mid 70s across the TN border. If the moist low level tomorrow can mix out, then everyone should expect 70s to low 80s across the south, but time will tell.

Wednesday closes out near-calm with surface winds taking on a more easterly direction as the parent high to our north moves further east slowly and the inverted trough weakens late in the evening. Lows on Wednesday night will be cool in the upper 50s to low 60s.

LONG TERM /THURSDAY THROUGH MONDAY/

Issued at 236 PM EDT Tue Sep 22 2026

Thursday through Monday...

Early fall weather is here! This pattern should last throughout Monday(ish) before our heat starts to creep back in. We remain in a light northeasterly flow at the surface, due to an upper level blocking pattern centered over southern Ontario. As we aren't pulling moisture from the Gulf, we will see lower dew points and RH values and remain mostly dry. On Thursday and Friday, expect to see highs in the low 70s, with overnight lows in the upper 40s and low 50s. Saturday morning is expected to be the chilliest of all, heading closer to low 40s across the region before starting our slow return to warmer temps. Expect sprinkles and the occasional shower from Thursday through Sunday, but long periods of rain aren't in the forecast. Lower clouds in the overnights and fog in the mornings is likely, but should be mostly clear skies throughout the day Thursday through Sunday.

Monday and Tuesday push back up toward the upper 70s as a high temp across the Bluegrass region with a gradient to the mid 80s toward the Bowling Green Area. As we heat up next week, we should still get a good diurnal cycle and cool to the upper 50s, bringing plenty of relief and letting us continue our fall hopes and dreams.

AVIATION /18Z TAFS THROUGH 00Z THURSDAY/

Issued at 143 PM EDT Tue Sep 22 2026

MVFR to patchy IFR ceilings will slowly improve to MVFR and low end VFR conditions this evening and overnight. NE flow will persist through the overnight as low-level moisture stays socked in. BWG may reach BKN VFR ceilings but conditions will worsen heading north and east from there. By Wednesday morning, ceilings will drop again to low end MVFR-IFR with isolated areas of LIFR possible. Rain showers will drift in from the east at LEX-RGA late in the TAF period. MVFR ceilings and a continued NE flow will dominate Wednesday afternoon.

LMK WATCHES/WARNINGS/ADVISORIES

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