textproduct: Louisville

KEY MESSAGES

* There is a level 1 of 5 (marginal) risk for severe weather beginning around 6pm EDT in southern Kentucky, and from midnight to 4 am in other areas mainly west of I-65. The primary hazard would be damaging wind gusts.

* In addition, thunderstorms tonight will bring a level 2 of 4 (slight) risk for excessive rainfall, with pockets of over 4 inches potentially resulting in flash flooding.

* Another round of storms is likely (50-80% chance) Saturday evening through Saturday night. These storms will also pose a risk for severe weather and excessive rainfall.

* Typical summertime temperatures with daily chances for isolated/scattered afternoon showers and storms is favored for much of next week.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 201 PM EDT Fri Jul 10 2026

***** TONIGHT *****

Early Friday afternoon, MRMS 12 hour radar estimated precipitation ranges anywhere from less than a tenth of an inch across some locations east of I-75 to more more than 3 inches in a swath immediately south of I-64 and in a few other localized pockets across central/west-central KY. In the wake of an MCV associated with last night's precip event, weak subsidence is suppressing convection, with only a few light showers observed across the area at this time. RAP mesoanalysis reveals a surface low beneath a mid level shortwave over northern Missouri, with a quasistationary front extending east across IL/IN/OH. Along and south of that front, additional thunderstorms are expected to fire over portions of Missouri and Illinois this evening, and subsequently ride eastward into our area overnight, lingering through much of the morning tomorrow. With a 20-30 kt LLJ over the area, Corfidi upshear vectors of 5-10 kt suggest back-building potential, and this scenario is depicted in several CAMs - with the axis of heaviest rainfall most likely to occur somewhere across either south/west KY or Tennessee. This is where the ECMWF Extreme Forecast Index (EFI) shift of tails (SOT) is present, suggesting the top 10% of ensemble membership is above the 99th percentile of model climatology, or in simper terms - there is notable potential for a significant/impactful event. In terms of actual rainfall amounts, HREF ensemble max through tomorrow evening features swaths of over 3 inches in those locations, with a few pockets of such high amounts also showing up further north where a deformation zone could set up on the stable side of any MCS (where instability is weaker but warm cloud processes dominate, leading to efficient rainfall). The main weather concern tonight into tomorrow will be flash flooding, however anything prior to about 2am EDT tonight could also pose a risk for gusty to locally damaging winds, particularly across southern and western portions of the county warning area (CWA) where an SPC level 1 of 5 (marginal) risk is in place.

***** SATURDAY AND SUNDAY *****

Like today, a diurnal minimum in storms is forecast tomorrow, with a 20-40% chance of convection during the late morning and afternoon hours, but with enough heating the atmosphere may destabilize once again to favor another evening-early overnight severe weather risk. Mesoscale processes will once again drive the magnitude and precise location of the heavy rainfall and flash flooding risk tomorrow night into early Sunday, but the potential is there for another wave of locally heavy rainfall (3+ inches) given the rich deep moisture (PWATs > 2 inches and "tall, skinny" CAPE profiles) and redevelopment of a 25-35 kt westerly LLJ.

Global models and their respective ensembles are slow to move the cut off low out of here as ridging attempts to nose in from the north, though fortunately the better dynamics and instability for heavy rainfall should shift south of the local area by Sunday. Still, the area is likely to see at least a few (20-40% coverage) diurnally-driven pop-up showers and storms during the afternoon and evening. Given the environment, highly localized pockets of heavy (3+ inches) rainfall remain a concern, and if these fall over locations that already received abundant rain (and hence have a low threshold for flooding), we could have a couple hydrological issues once again.

LONG TERM /SUNDAY THROUGH THURSDAY/

Issued at 201 PM EDT Fri Jul 10 2026

The synoptic pattern across the CONUS will become dominated by expansive upper ridging for at least the first half of next week as a 600+ dm 500 mb high sets up across the northern Plains. While the Ohio Valley will be on the southeast edge of this upper ridge, residual mid- and upper-level energy from this weekend's storm system is expected to meander across the TN/mid-Miss. Valleys from Sunday through at least Tuesday before drifting farther to the west. As this weak upper low remains in our vicinity, moisture levels should be seasonable if not a bit above climatology, with ensemble mean PW around 1.5". Moisture will be richer as you go to the south, supporting higher chances for showers and storms through early next week.

There is some discrepancy in the exact position of the upper disturbance early next week, with the ECMWF and its ensembles displaced to the south of the GFS. This will impact daily shower and storm chances next week, especially after Monday, with the GFS favoring a more unsettled pattern while the ECMWF is generally drier. If storms are able to develop each afternoon, weak flow aloft should lead to mainly garden-variety, slow moving summer storms with minimal severe potential. Given the likely slow movement of storms, a lingering heavy rainfall/flooding threat can't be ruled out, though limited coverage of storms should limit this threat. Otherwise, temperatures should be fairly seasonable with highs in the upper 80s to around 90 and lows in the upper 60s and low 70s.

Thursday into next weekend, a more substantial upper trough is progged to descend across the eastern part of North America. Medium- range guidance still features quite a bit of spread as to how much this feature will be able to push the upper ridge back to the west, which will impact the forecast for late next week into the following weekend. If the trough is able to dig more to the south/west, it would bring a front down into the Ohio Valley that would increase storm chances/coverage Thursday into Friday. However, a more resilient upper ridge would support warmer and drier weather over the same period.

AVIATION /18Z TAFS THROUGH 00Z SUNDAY/

Issued at 135 PM EDT Fri Jul 10 2026

Aside from a low (10-15%) chance for a pop-up storm, the weather should remain dry at the airfields until after around 06z tonight, when scattered to numerous showers and a few embedded thunderstorms overspread central Kentucky and southern Indiana. Storm coverage should begin to wave after around 13z Saturday, but there is a 30- 50% chance that MVFR ceilings linger until near the end of the forecast period.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Flood Watch through late Saturday night for KYZ023>043-045>049- 053>057-061>067-070>078-081-082. IN...Flood Watch through late Saturday night for INZ076>079-083-084- 089>092.