textproduct: Louisville

KEY MESSAGES

* Widespread rainfall on Tuesday ranging from .33" to 1" for most across Kentucky. Lesser amounts across southern Indiana.

* Localized amounts of 2 to 3" possible on Tuesday, mainly along and south of the Western Kentucky and Bluegrass Parkway. A few instances of Flash Flooding possible.

* High pressure building and waning at the mid levels this week will provide episodic bouts of showers in our southern counties, with areas along and north of the Ohio having the best chance of remaining dry into next week.

* At or below normal temperatures and cool NE flow brings stretches pleasant weather into early next week.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 325 PM EDT Mon May 25 2026

Interesting setup across the eastern half of the CONUS as an upper low spins near the Red River Valley, and upper ridging is anchored off the SE CONUS. Deeper moisture will continue to be pushed northward into our region between these two features while a nearly stationary surface boundary also hangs over the area. The end result will be periods of rain showers, and perhaps a few storms through early to mid week.

After some morning fog and low clouds, conditions have improved with breaks in the sky cover. This has allowed temperatures to surge into the mid and upper 70s. Expect we'll see some patchy dense fog again tonight as a stalled frontal boundary stays near the area, surface winds remain light and variable, and a lot of low level moisture lingers. Have added a good amount of fog to the grids, but there is some uncertainty in how widespread or dense it might become, if at all.

Scattered showers have developed across central and southern KY today associated with the PWAT plume in the 1.5" to 1.6" range, and some mid level deformation/convergence evident on 700 mb streamlines. Given the very weak vertical shear profiles, showers have been very slow to stationary in movement, and a few localized rainfall amounts have added up. Dual pol estimates between 1" and 1.5" have been noted in NW Logan county. This would be considered an overachievement for today, and it does appear that the overachieving theme for isolated locations could continue into tomorrow.

The biggest focus of the near term will be for Tuesday when a plume of deep moisture characterized by PWATs in the 1.8" - 2" will move south to north across the region, bringing widespread rainfall, with pockets of locally heavy rainfall possible. The heaviest and most widespread swath of rain is expected across central and southern KY where fairly widespread .5" to 1.5" amounts will be possible. However, 25/12z PMM data suggests that localized pockets of rainfall between 2-3+" is also possible. Given the slow storm movement, some modest instability, PWATs near record highs for this time of year, and and a notable mid level deformation zone that may allow for some training, do think we could run into some localized flood concerns for tomorrow. 1,3 and 6 hour FFG values are a bit compromised given the recent heavier rainfall amounts, and while the HREF 48 hour mean amounts aren't really concerning, the Max, PMM, and LPMM data all point to locally higher amounts. Given the reasons above that can contribute to these locally higher amounts, think it is a pretty good bet that a few Flood Advisories or Flash Flood Warnings may be needed tomorrow across central KY. Did collaborate with with WPC and surrounding offices on a possible Flood Watch and/or upgrade to Slight Risk for the Day 2 ERO, but it was ultimately decided that potential seems too isolated for a watch at this time. So, will message with graphics and continue to monitor data trends for now. It is possible that a Watch may still be lifted before tomorrow morning. At this time, the best focus looks to be mostly along and south of the Parkways for the heaviest rainfall axis.

The same general pattern holds through Wednesday with numerous showers and a few storms continue across the area as deep moisture is funneled into the Ohio River Valley between the two stationary upper features. Marginal ERO outlooks continue into Wednesday as a result of this pattern/setup. Temperatures look to be slightly warmer on Wednesday with highs in the upper 70s and low 80s. Expect smaller diurnal trends toward lows in the 60s each night as heavy cloud cover and high dew points limit the temp drop too much.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/

Issued at 325 PM EDT Mon May 25 2026

Thursday - Saturday Night...

Thursday morning begins with leftover showers, producing an additional trace to <0.1", though the CWA has a 50-70% chance of remaining dry in the morning. Otherwise, morning clouds will eventually break up some in the afternoon as a high pressure centered over the Great Lakes tries to dry us out. There still remains some uncertainty with how warm we get on Thursday based on the strength and location of this high to our north. Should this high drift a little further south or be a little stronger, dry air at mid-levels will begin to clear clouds from north to south, allowing temperatures to warm into the low to mid 80s counteracting a cool NE flow, which is what is forecast for now. If the high can't quite influence highs in our CWA, clouds and NE flow will cool temperatures into the mid to upper 70s.

Regardless, the mid-level to surface level high pressure will begin to weaken and drift north towards a parent high in central Canada in what seems like an Omega pattern building towards the end of the week. As this high wanes some, a stalled boundary to our SW will slowly drift NE close or just over our southwestern counties, bringing more mid-level moisture, clouds, and rain chances. The exact placement of this boundary is still uncertain, though rain low PoPs will remain in our southern/SW counties during the afternoon on Friday leading into Saturday morning. Temperatures on Friday warm from the low 60s into the mid to upper 70s. Latest LREF probabilistic trends are keeping an axis of moisture along this boundary to our southwest, with an average rainfall total of 0.2" or less in our southern border counties.

Clouds with spotty showers in the south continue into Saturday morning with temperatures in the upper 50s to low 60s. The aforementioned axis of moisture will sink to the south and east as a mid-level/surface level high pressure rebuilds in from the north. This high should dominate our weather into early next week, providing a stretch of recovery from the wet weather we've had the past several days. This setup favors a dominating NE flow this weekend, meaning highs should be near or just below normal. Especially considering this pattern is expected to hold through early next week, temperatures will be slightly cooler as long as we stay on the cool side of the high centered over central Canada. I suspect latest NBM data is too warm biased, so for now I am forecasting highs in the upper 70s Saturday, though will monitor a cooling trend as the weekend approaches.

Sunday - Tuesday...

NE flow will continue into Sunday in this blocking pattern from a strong high centered over central Canada. Skies should become relatively clear, with highs still a little cooler than normal. Should this cooling trend fail to be realized with additional solar heating or maybe the ridge moves much further east than expected, NBM suggests highs in the upper 70s once again. Dry weather will continue into early next week with PWATs being near the 25th climatological value, ranging 0.75-1" Sunday into Monday and Tuesday.

Calm and pleasant weather thus will continue through Tuesday. Highs will be in the mid to upper 70s Monday to low to mid 70s on Tuesday. Looking ahead, the dry pattern seems to remain holding strong into Wednesday as well.

AVIATION /00Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 737 PM EDT Mon May 25 2026

We are currently seeing VFR conditions under a mid level cloud deck. These conditions will continue for about six hours, before CIGs and VIS reduce with patchy fog and rain showers. Showers and lower CIGs will work north through the early morning hours. By sunrise, CIGs will likely be low-end MVFR and possibly IFR in some areas. Heavy rain bands and showers will move over the region and may bring VIS down to 1-2SM at times. In the early afternoon, precip will break up and we will then see more scattered showers and maybe a few storms.

LMK WATCHES/WARNINGS/ADVISORIES

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