Louisville, KY 40241 Weather

Key Messages

* Patchy dense river valley fog is possible early this morning.

* Beautiful weather is expected into early next week. Dry weather will continue through at least next Tuesday.

Discussion

Issued at 330 AM EDT Wed Oct 21 2026

====== Pleasant Weather with Cool Mornings and Warm Afternoons =====

It is a clear, cool morning with temperatures ranging from the upper 30s in decoupled valleys to around 50 degrees on ridges. Most places will see temperatures bottom out in the upper 30s and lower 40s this morning. Winds are calm - high pressure at the surface continues to influence our weather. River valley fog has just started to develop in portions of central KY, and we'll likely see fog expand at least along the Kentucky and Cumberland rivers through sunrise. Patchy fog will be possible elsewhere, most likely near rivers and in typical fog-prone locations.

Broad mid and upper level ridging remains in place over the central CONUS today. There is a weak mid-level shortwave disturbance generating some mid-level clouds early this morning across portions of KS and western MO, but this feature is forecast to dive southeast over the Lower MS Valley later today. We'll enjoy sunny skies with afternoon highs in the low to mid 70s. Based on yesterday's observed high temps and model 1000-850 mb thickness trends, decided to go slightly warmer than the NBM for highs today. The only other short term change was to again lower afternoon dewpoints, as afternoon mixing to near 4 kft should bring some drier air aloft to the surface. This will likely produce afternoon RH values in the 25-35 percent range, though a light NE wind will keep the fire danger low.

The forecast heading into the weekend is largely unchanged. Upstream ridging aloft, combined with sfc high pressure centered off to our N/NE, will preserve the dry airmass and give us a stretch of spectacular weather. Expect several dry days with fairly steady temps as well (chilly early mornings and pleasant afternoons).

The upper level ridge slowly drifts east with time and finally moves overhead this weekend. Model consensus suggests the ridge will deamplify through the early to middle portion of next week, with an active pattern emerging across the north-central US. The vast majority (>90%) of ensemble members keep us dry through next Tuesday, however. Forecast confidence is much lower beyond Tuesday due to increasing model spread.

Aviation

Issued at 647 AM EDT Wed Oct 21 2026

HNB will start this forecast period with brief IFR fog before conditions improve. Prevailing VFR conditions are then expected after 13Z. Winds will be very light out of the northeast today, and skies will remain clear. Patchy fog will be possible again early Thursday, with vis reductions most likely at HNB.

Lmk Watches

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