textproduct: Louisville

KEY MESSAGES

* Flood Watch remains in effect for localized areas of additional 1- 2" of rain causing flash flooding concerns.

* Rainfall totals heaviest in our NE CWA ranging 0.25 - 0.75" with less than 0.5" elsewhere by Thursday morning.

* Dense Fog Potential: Clearing skies combined with recent rain and saturated ground could lead to the potential development of dense fog early Thursday morning.

* Mostly dry through the weekend, and into early next week. Some shower and storm chances across southern KY this weekend. Temperatures around normal.

SHORT TERM /THROUGH THURSDAY NIGHT/

Issued at 321 PM EDT Wed May 27 2026

This Evening - Thursday Night...

Widely scattered showers and storms will continue to move ENE across our southern/central KY counties over the next several hours. So far, no severe weather has occurred with these storms but the Marginal Risk will continue as daytime heating builds. Surface instability remains high with SBCAPE ranging ~1500-2000 on average, though maximum SBCAPE reaches 3000 J/kg in isolated spots. Shear in low to mid levels is somewhat weak remaining just under 30kts along our eastern border, decreasing as one heads west from there. As a result, the main severe risk remains severe to strong winds and low end severe hail possible as well.

Additionally, a flash flood threat remains for the CWA, especially in our counties along and north of I-64 and NE of Louisville. A Flood Watch remains in effect until overnight Thursday for localized areas of flooding. Latest radar scans along with latest HREF data indicates the worst flash flooding threat may remain NE of our CWA. However, considering FFG guidance indicating less than an 1" in 1 hour is enough to create flash flooding, the Flood Watch will remain in its current area. This is due to training showers and storms with rainfall rates of more than 1" possible as they drift in from the NW later this evening. The greatest concern is for Jefferson County, IN and Harrison, Bourbon, and Nicholas Counties as they'll be the closest to the heavier rainfall rates. Our Southern CWA will eventually dry out later this evening and miss out on the batch of showers and storms scheduled to move over our NE counties. HREF 25th to 75th percentile rainfall totals range in the 0.25 - 0.75" across the Flood Watch areas, with localized 1-2" inches possible. Elsewhere, most of the rain has already fallen, with overall totals ranging 0.1 - 0.5". High temperatures will be in the upper 70s and low 80s.

Eventually, showers and storms move east and weaken overnight from the loss of daytime heating. High level clouds remain overnight but will thin before sunrise. This should allow enough cooling for fog to form, especially in areas that will not have time to dry out from this evening's rain. Winds will be calm and there will be plenty of moisture at the surface, but the only limiting factor would be the high cloud cover to inhibit nocturnal cooling overnight.

Later on Thursday, with the sun rising and still some light high level cloud cover, morning fog will gradually mix away leading to a nice dry break Thursday afternoon. NE flow will dominate during the day as a high pressure over the Great Lakes keeps us dry. Highs are still warm in the low 80s. A low pressure building well off towards our SW will keep the high clouds around throughout the day and into the evening with a continued surface NE flow. Despite this, increased cloud cover Thursday night in the SW will keep lows warmer in the low to mid 60s with mid 50s to near 60 across central KY and our NE counties.

LONG TERM /FRIDAY THROUGH WEDNESDAY/

Issued at 321 PM EDT Wed May 27 2026

Friday - Sunday...

Quite an interesting upper pattern through the weekend as central CONUS omega block is bookended by anomalous closed lows over the western and eastern CONUS. For the most part, we'll be under the influence of the upper ridge, and surface high pressure centered around the Great Lakes region. This will keep us mostly dry, however we'll have to focus on southern KY as a stalled boundary just to the south could provide focus for scattered diurnally driven shower and storm potential each day. Will continue with isolated to widely scattered shower and storm chances down across southern KY, however the rest of southern Indiana and central Kentucky are expected to stay dry through this stretch.

LREF probabilities along the southern KY/TN border for measurable rainfall are ranging in the 30-50 percent range each day, however probabilities for above .25" of rain each day drop off to 10% or less. So, not expecting large amounts of rainfall at the moment. Temperatures during this stretch should be pretty near normal values for this time of year in the upper 70s and low 80s.

Sunday Night - Wednesday...

The upper ridge axis will retrograde west early next week as reinforcing shortwaves dig into the eastern CONUS trough. This progression will help to push the aforementioned surface boundary farther to the south and out of play. In addition, surface high pressure builds in over the area as well. Dry conditions will continue with near normal temperatures in the upper 70s and low 80s. It is also worth noting that dew points will likely stay in the low to mid 50s next week. By mid week, the upper ridge axis slides back toward our region as the eastern CONUS height anomaly slides off the New England coast. Dry conditions continue.

AVIATION /00Z TAFS THROUGH 06Z FRIDAY/

Issued at 722 PM EDT Wed May 27 2026

A few scattered showers and storms are currently moving eastward through the northern half of the forecast area. PROB30s for HNB/SDF/LEX/RGA included till 03z for these showers to move through. Winds will start to shift to NNE overnight, and also become calm for majority of the night. That being said, patchy fog is expected to affect all sites tonight into the morning. Fog could become thick briefly causing MVFR and IFR conditions. After daybreak, the fog will clear and all sites will return to VFR conditions.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Flood Watch until 2 AM EDT Thursday for KYZ030>043-048-049-057. IN...Flood Watch until 2 AM EDT Thursday for INZ078-079-092.