textproduct: Louisville

KEY MESSAGES

* Aside from a couple garden variety showers and possibly (15% chance) a thunderstorm across areas mainly east of I-65 Wednesday afternoon, dry weather should persist through Thursday.

* Thunderstorm chances, along with summer warmth and humidity, will increase later this week, peaking at 40-60% Friday into Saturday.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

Issued at 119 PM EDT Mon Aug 3 2026

***** THROUGH WEDNESDAY NIGHT *****

At 1pm EDT Monday, a cutoff low was spinning over northwest Georgia, while shortwave ridging was poking into central KY/southern IN in its wake. Temperatures ranged from the lower-mid 70s east of a roughly Glasgow to Lexington to upper 70s/lower 80s further west where skies had become mostly clear. We'll likely add another 1-3 degrees to these readings through mid-late afternoon, but then with mostly clear skies overnight temps should drop into the low-mid 60s.

Easterly flow on the north side of the low situated over Georgia tomorrow may bring a couple thunder showers into areas near the Cumberland Plateau, but HREF/REFS/NBM agree that coverage should be minimal (less than 15%) and entirely east of a Burkesville to Lexington line. That low will meander back northward on Wednesday, providing weak surface convergence that may trigger a couple showers and storms in areas mainly east of the I-65 corridor where surface dewpoints are forecast to climb back into the low 70s. At this time, NBM gives areas east of a roughly Bowling Green to Frankfort line the best chances (40-60%) for garden-variety storms (highest east). Temperatures both Tuesday and Wednesday are forecast to climb into the mid to perhaps upper 80s - near to slightly below normal for early August.

LONG TERM /THURSDAY THROUGH SUNDAY/

Issued at 119 PM EDT Mon Aug 3 2026

***** THURSDAY THROUGH THE WEEKEND *****

Global models and their respective ensembles agree that an expansive trough will move into the area from the Northern Plains and Upper Midwest late Thursday into Friday. Southwest flow ahead of this system will bring deeper moisture and a slightly warmer airmass to the Bluegrass state on Thursday, when NBM advertises a 30-60% chance high temperatures surpass 90 degrees along and west of I-65 (highest chances south of US 62). Precipitation chances roughly split the area during the day, as the incoming trough axis remains upstream across IL and the aforementioned cutoff low gets pushed northeastward into the Mid-Atlantic. However, Thursday night some decaying convection may enter northern portions of the area.

Storm chances increase area wide by the end of the work week as a couple shortwaves rounding the base of the upper level trough swing through the region. Uncertainty surrounds the degree of destabilization that may materialize each day due to potential for cloud cover, but LREF mean wind shear runs at only 10-20 kt through the weekend which should limit storm organization. Still, pop up storms each afternoon and evening are a risk, with the highest chances (40-60%) on Friday. Any storm could generate locally heavy rain given PWATs approaching 2 inches, slow storm motion, and a deep (> 13kft) warm cloud layer, but the probability of severe weather - at least at this juncture - appears low (less than 15%).

Around the end of the forecast period, uncertainty increases in the upper level pattern, with a dipole in Empirical Orthogonal Function (EOF) 1 for 500mb heights suggesting this is primarily driven by model variance in when ridging over the Intermountain West spreads east into the Ohio Valley/Great Lakes. From cluster analysis, 2 broad solutions become apparent by Sunday-Monday: ~45% of long range ensemble members depict ridging fully over KY/IN by Monday, favoring heat indices in the triple digits and minimal chances for precipitation; meanwhile the remaining members (55%) lean towards a more zonal/northwest flow solution that would result in slightly milder temperatures (mid 80s) and keep a risk for scattered storms around, especially north of I-64. WPC's day 8-14 probabilistic hazards outlook highlights the local area with a slight risk for both heavy rainfall and extreme heat.

AVIATION /12Z TAFS THROUGH 18Z TUESDAY/

Issued at 652 AM EDT Mon Aug 3 2026

As the morning fog clears the ceilings will also begin to improve for all sites. By 16-18z, all sites will be back to VFR and remain for the forecast period. Skies will begin to clear this evening with only SCT/FEW250 into the night. Winds remain mostly light out of the NE, with the exception of a possible brief period this evening with gusts around 15kts.

LMK WATCHES/WARNINGS/ADVISORIES

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