textproduct: Louisville

KEY MESSAGES

* Chances for areas of patchy dense fog continue through early Monday morning.

* Mostly dry weather is expected north of the Bluegrass Parkway Monday, with scattered showers and isolated storms possible for places south.

* Episodic bouts of showers/storms are expected to continue through most of this week. Localized excessive rainfall may result in flooding in some areas.

UPDATE

Issued at 139 PM EDT Mon May 25 2026

Interesting setup across the area this morning with mid level moisture transport between upper low over the Red River Valley, and upper ridging over the SE CONUS. Meanwhile, a surface boundary resides down near the KY/TN border. 700 mb streamline analysis shows a classic col over our region, with mid level deformation zone stretching WSW to ENE across our CWA. Along and south of this axis, PWATs are in the 1.5-1.6" range across southern KY where some isolated to widely scattered showers are noted. Very little vertical shear throughout the column, and with the mid level deformation, these showers are nearly stationary. As a result, will have to watch for isolated areas where rainfall totals begin to add up through the day. Overall, not expecting much in the way of problems.

A bit more concerned about Tuesday when more widespread rainfall is expected with a deeper moisture surge rotating northward between the two upper features mentioned above. PWATs look to surge into the 1.8" to 2" range along and south of that same deformation axis mentioned above. Right now, this axis looks to mainly be along and south of the Parkways. Some of the 15/00z HREF PMM data suggests that pockets of 2-3" could occur under this setup, and given the very moist column, slow storm movement, and a little bit of instability, do tend to buy into that scenario. As a result, will be considering a possible Flood Watch for tomorrow once we are able to get a look at the 12z HREF data.

SHORT TERM /THROUGH TUESDAY/

Issued at 352 AM EDT Mon May 25 2026

A weak cold front continues to slowly drift southward across the Commonwealth, with current expectation of it becoming nearly stationary over southern Kentucky by Monday afternoon. Additionally, observations are showing areas of fog developing across the area. This should only last for a few more hours before conditions quickly improve after sunrise this morning. The highest HREF probabilities of visibility less than 1/2 mile are around 60% east of I-65 and north of the Cumberland Parkway, with lower probabilities for the rest of the CWA.

With the front draped over Kentucky, the coverage of showers and a few thunderstorms will be mostly limited to areas south of the Bluegrass Parkway. Accumulations will be fairly light, with HREF probabilities for rainfall greater than 0.25" only getting up to 60% in our far southeastern counties near the Tennessee border. Temperatures will be just below normal for this time of year, with highs in the mid-to-upper 70s forecast.

Monday night into Tuesday, the frontal boundary will begin to slowly drift northward over Kentucky as southerly flow aided by an Atlantic ridge carries rich moisture northward into our region. Additionally, multiple perturbations from the gulf states trek towards us, acting as a forcing mechanism for additional showers and storms to develop. With HREF showing PW values over 1.8" (>98th percentile climatologically), more widespread showers and isolated to scattered storms are expected across the area. Temperatures will be similar to Monday, with highs in the mid-to-upper 70s.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/

Issued at 352 AM EDT Mon May 25 2026

Tuesday Night - Wednesday...

As the frontal boundary continues to drift northward, coverage for showers will increase throughout the entire CWA. With southerly flow still in place, LREF shows PW values exceeding 1.7" through Wednesday. Diurnal heating will allow for some scattered storms to develop during the afternoon, though a limited wind shear profile will keep our chances for severe weather to be near-zero. Given the persistent cloud cover from the showers and storms, temperatures will continue to struggle to get above 80, though some places in our far southern counties could get there.

Wednesday Night into the Weekend...

The pattern begins to shift Wednesday night as upper-level troughing over eastern Canada digs southward towards the Ohio Valley. Additionally, upper-level ridging builds in, with an axis extending from the central CONUS to the southeast. A cold front moves over the region late Thursday, pushing the main area of moisture out of the region just to our south and west. While a few showers and storms are possible Thursday, the highest chances will be south of the BG Parkway. The moisture axis will fluctuate some Friday and Saturday as the upper ridge shifts slowly to the east. Another cold front will push through the area late Saturday into Sunday, that could set up another period of drier weather to close the weekend. Once the initial cold front on Thursday moves through, temperatures will hover in the mid-to-upper 70s range to close out the forecast period.

AVIATION /18Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 139 PM EDT Mon May 25 2026

The TAF sites have found their way back to VFR conditions, and this should remain the case through the afternoon, evening, and the first part of the overnight. We'll likely keep a Sct-Bkn mid deck along with Bkn-Ovc upper sky cover. Surface winds will be light and variable out of the east given a stalled frontal boundary near the area, however any notable gradient wind will likely prevail out of the ENE to ESE through the TAF period.

Early tomorrow morning, another surge in moisture will lift S to N across the area bringing lowering ceilings, widespread light rainfall, and embedded stronger rain showers or a few storms. Looks like ceilings could dip into the IFR to low MVFR range, with visibilities also dipping into the low MVFR to brief IFR range in any heavier showers. Tried to time out the heaviest rainfall around sunrise down near BWG, and then from mid to late morning through into the early afternoon across the northern TAF sites.

LMK WATCHES/WARNINGS/ADVISORIES

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