textproduct: Louisville

KEY MESSAGES

* Chances for showers and thunderstorms return this afternoon across southern KY, spreading to the north this evening into tonight. The main threat from storms will be heavy rainfall and lightning, and isolated flooding cannot be ruled out across southern KY.

* Drier conditions return Saturday into Saturday night, before another lower chance for showers and storms returns mainly across southern KY Sunday into Monday.

* A much drier weather pattern will take shape across the region during the middle of next week. The current forecast features mainly dry weather for much of next week, with near normal temperatures.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 321 AM EDT Fri May 29 2026

Today and Tonight...

Quiet conditions are present across the region this morning as surface high pressure to the north and northeast of the region is in control. Anticyclonic and divergent flow out of the high has sustained a light E/NE wind overnight, ushering drier air into the area. At this hour, a notable gradient between sfc dewpoints in the low 50s and the low-to-mid 60s is observed across KY and southwest IN, with drier air expected to continue to work into the area over the next few hours. The drier air has limited any fog development, and would expect any fog that does try to develop to be very patchy and confined near bodies of water.

Today, omega pattern in the upper-level height field will build across the north central CONUS and central Canada with troughs located across the northeast and western CONUS. A shortwave descending within the northeast US troughing will cause the sfc high over the Great Lakes to weaken later today, while a weak disturbance associated with the western CONUS trough is expected to break off and travel eastward from the Plains across the southeast US tonight into tomorrow morning. As a result, the drier NE flow is expected to weaken later today, with the high PWAT air mass creeping back to the northeast this afternoon into tonight.

For today, dry conditions are expected across much of the area, with scattered mid- and high-level clouds and high temperatures in the upper 70s and low 80s. Across the southwestern one-third of the CWA (Ohio County over to Russell County and points south), the moisture return later today should support a sufficiently unstable air mass for showers and thunderstorms to develop this afternoon and evening. As the air mass with >1.75" PWATs creeps farther northeast tonight, rain chances will increase toward the Ohio River and the I-64 corridor, though coverage should be more isolated than locations across south central KY. Weak deep-layer shear should limit the potential for strong to severe storms; however, taller cells could produce strong downdrafts leading to gusty winds on the order of 25- 35 mph.

There is some potential for heavy rainfall and isolated flooding across south central KY given the latest suite of hi-res guidance. With mean cloud layer winds only around 10 mph and even weaker Corfidi propagation vectors, storms will be fairly slow-moving, increasing the potential for heavy rainfall. Additionally, deep warm cloud depths (~14 kft) and the high PWAT air mass will create an environment favorable for efficient, heavy rainfall. Both the 0Z HREF and REFS ensembles show a few 6-hr LPMM swaths of 2-4" along and south of the Cumberland Parkway, and those rainfall amounts (if accurate) would support localized high water/minor flooding. For locations across south central KY outside of the heavier swaths, average rainfall amounts should be around 0.25-0.50".

Saturday and Saturday Night...

The subtle mid-level disturbance causing the increase in moisture this afternoon into tonight is expected to be absorbed into the main trough across the northeast US on Saturday, allowing for high pressure to strengthen once again over the Great Lakes. Another surge of northeast low-level flow should help to push drier air back into the region, causing lingering rain showers to drop back to the southwest toward the TN Valley. Enough moisture will linger for isolated showers and possibly a storm with daytime heating Saturday, though this chance should primarily be confined to our southwestern counties. Otherwise, a mix of sun and clouds is expected on Saturday, with highs in the upper 70s and low 80s.

Saturday night, continued northeast flow should allow dewpoints to continue to fall from NE to SW. Where sfc dewpoints are the lowest, temperatures should be able to fall more Sunday morning, with forecast lows ranging from the low 50s in the northeast CWA to the low 60s in the southwest CWA. ranging from the low 60s

LONG TERM /SUNDAY THROUGH THURSDAY/

Issued at 321 AM EDT Fri May 29 2026

Sunday through Monday Night...

The large scale pattern is not expected to change much for the second half of the weekend into the beginning of next week, with upper troughing expected on either side of a highly-amplified blocking ridge over the central part of the US and Canada. The plume of greater moisture, after retreating to the south and west Saturday night, is expected to creep back to the northeast once again during the day on Sunday. While this should lead to a return of shower and storm chances, especially in south central KY, the air mass won't be quite as rich (PWATs 1.6-1.7") and forcing is less well-defined, so coverage and magnitude of showers and storms should be lower overall.

The chance for mainly afternoon and evening showers and storms should continue from Sunday afternoon through Monday evening as a fairly stagnant pattern remains in place across the Ohio Valley. Highs Sunday and Monday are expected to range from the upper 70s to the low-to-mid 80s with low temperatures Sunday night expected in the upper 50s and low-to-mid 60s.

By Monday evening, another surge of drier air from the north and northeast is expected to sweep the humid air mass back to the south and west. This time, the sfc high pressure that will bring about the change should be stronger, with the plume of high PWATs expected to sink into the Gulf and west of the Mississippi Valley. This should lead to a return to dry weather across the area as we head from Monday night into Tuesday.

Tuesday through Thursday...

Upper-level ridging and sfc high pressure should dominate through the middle of next week, with dry conditions and near to slightly below normal temperatures favored from Tuesday through Thursday. By the end of the current extended forecast period, the upper-level block is expected to break down, causing the pattern to become more zonal and progressive across North America. While this will lead to a gradual return of moisture and precipitation chances by the end of next week, the better rain chances are favored to hold off until Friday into next weekend.

AVIATION /12Z TAFS THROUGH 18Z SATURDAY/

Issued at 654 AM EDT Fri May 29 2026

VFR conditions will continue at all sites this morning and through at least the early afternoon hours with scattered high level clouds and light E/NE winds generally between 5-10 kt. Later this afternoon, isolated showers and storms are expected near BWG, with all other sites remaining dry. While coverage is still low enough to go with PROB30 instead of prevailing TSRA, this may need to be adjusted depending on model trends later today.

Otherwise, light winds and VFR conditions are expected tonight into the end of the current TAF period at all sites except BWG. Moisture pooling along a weak front could lead to IFR/MVFR CIGs and VIS around BWG, especially after 06Z tonight.

LMK WATCHES/WARNINGS/ADVISORIES

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