textproduct: Louisville

KEY MESSAGES

* Cold front approaching from the northwest will fire off scattered showers/storms later this afternoon and evening, mainly across southern IN and north central KY. Main impacts would be strong gusty winds, heavy downpours and lightning.

* Weekend will be mainly dry and warm with highs around 80 degrees. Low end chance of scattered to isolated showers/storms on Saturday across southern and eastern KY.

* Severe Weather potential for Monday afternoon and evening as a low pressure system moves through the region. The setup is favorable for severe storms, though confidence in details remain low at this time.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 257 PM EDT Fri Apr 24 2026

This Afternoon and Evening...

At this hour, isolated showers and a scattered cu field have developed across the area, likely along differential heating boundaries as low-level moisture continues to increase from west to east across the lower Ohio Valley. Limited cloud cover this morning allowed temperatures to warm into the upper 70s and low 80s, hitting convective temps across the area. Current mesoanalysis data shows around 500-1000 J/kg SBCAPE across the area, with limited instability in the 700-500 mb layer largely keeping a lid on deep, explosive convective growth so far this afternoon.

As we head through the next several hours, would expect additional convective initiation across the area, with the greatest concentration of showers and storms expected along and west of I-65 where the richer near-sfc moisture resides. In spite of the meager mid-level lapse rates, an isolated strong storm will be possible through mid-evening, with gusty winds being the primary storm hazard in addition to heavy rain and lightning. Given the limited overall forcing, would expect convective intensity to diminish rapidly after sunset, though rain showers should continue later into the evening hours. While many locations will see no rain (and those which do see a shower should generally receive less than 0.25"), 6-hr HREF LPMM data shows narrow swaths of high-end rainfall amounts to around 1- 1.5" where any training of heavier storms occurs. With that being said, flash flooding is unlikely given the particularly dry antecedent conditions.

Tonight...

A general dwindling of precipitation coverage is expected between 9 PM and midnight as lingering showers/storms weaken. However, as a cold front stalls over the region tonight, deeper moisture will linger, particularly across KY. Additional rain shower chances are in the forecast, with the greatest probabilities along and south of the KY Parkways after midnight tonight. Not expecting significant amounts with this activity, with most locations receiving 0.25" of rain or less. Outside of any shower chances, lingering low-level moisture will lead to favorable conditions for fog/mist development, especially in areas that receive rain this afternoon. HREF probabilities of less than 1 mile vsbys range from 20-50% across much of the area, so that's something we'll have to look out for overnight. Temperatures should remain mild with lows only in the upper 50s and low 60s.

Saturday and Saturday Night...

By Saturday morning, the remnants of the sfc "cold" front will be draped across the Ohio Valley, with the front most apparent as a wind shift and a moisture gradient. In the vicinity of this gradient and points south, low clouds and a few lingering showers should continue Saturday morning, with llvl moisture expected to mix up into a stratocu layer by midday. As daytime heating increases, llvl moisture south of the front should be great enough for isolated to scattered showers, and possibly a thunderstorm, to develop. The best chances for this (20-40%) will be along and south of the Parkways. Points to the north and west could see scattered cu develop, but decreasing moisture should limit precip chances. Winds behind the front should veer around to the N/NE, with speeds up to 10-15 mph expected. Temperatures will be pleasant on Saturday, with highs in the mid-to-upper 70s likely.

Saturday night, drier and somewhat cooler air will continue to push across KY from the N/NE. Clearing skies are expected during the evening hours, although an additional stratus deck may try to push into the Bluegrass from Ohio by early Sunday morning. Given this light cooler/drier flow, lows should be able to fall into the 40s and low 50s across much of the area Sunday morning.

LONG TERM /SUNDAY THROUGH THURSDAY/

Issued at 358 AM EDT Fri Apr 24 2026

***Saturday and Sunday***

Cold front will push through early Saturday morning with a weak mid- level impulse following behind. That should be enough lift for a few isolated to scattered showers and storms (20-40%) mainly south of the parkways into the Lake Cumberland region. Sfc high pressure is expected to build in from the north as upper ridging builds back in over the Ohio Valley late Saturday into Sunday. We will remain above normal each day with highs in the upper 70s to low 80s.

***Potential Severe Weather Threat Monday***

--Synoptic Setup--

Deterministic model guidance continues to show a favorable mesoscale setup for potential severe weather across parts of the Mid- Mississippi Valley and the western Ohio Valley on Monday. A shortwave trough coming onshore off the central CA coast will track across the Desert Southwest and into Central Plains by Monday morning. Strong surface cyclogenesis will develop a deepening sfc low over the Central Plains Sunday Night. The negatively tilted mid- level shortwave trough and sfc low will then work northeast into the Upper Midwest and Great Lakes Monday night into Tuesday. This will lift a warm front across the Ohio Valley during the day Monday as Gulf moisture is drawn northward into the region. Aloft, a strong mid-level jet core will setup over the mid/upper Mississippi Valley providing strong upper-level divergence over the region, mainly across the western Ohio Valley. There will also be a strong LLJ ahead setting up over the Ohio Valley late Monday resulting in ample shear supporting organized storm structures before becoming more linear along and ahead of an approaching sfc cold front Monday night into Tuesday morning.

--Confidence in Severe Threat--

Given that we are still 4-days out from this event, will continue to hold on to a low end Medium confidence for severe weather potential but the latest 00z deterministic guidance has significantly backed off on overall severe threat for central KY and southern IN. Both the GFS and ECMWF are trending slower and have backed off on the amount of available instability. While the GFS continues to be the more aggressive of the two models with higher SBCAPE (1000-1500J/kg) both models now hold off until Monday night to bring in the convection with a strong capping inversion in the afternoon. While the current guidance trend is backing off on the threat, CIPS Analog, CSU Machine Learning probabilities, and NCAR AI NWP have actually shifted a little more east. While the SPC Day-5 outlook expanded the Slight Risk (level 2/5) towards I-65 and added an Enhanced Risk (level 3/5) across the Mid-Mississippi Valley. We will see what happens later this morning when SPC released their day-4 outlook, but it is the opinion of this forecaster that we will likely see little overall change with this update.

--Impacts--

While confidence is high that far western KY across the Mid- Mississippi Valley has the highest probability of experiencing severe weather on Monday, with all threats on table from damaging winds, large hail and tornadoes possible, there are still a lot of unknowns as we go into the weekend and fine details that need to be worked out. As you work eastward from western KY towards I-65 and into eastern KY the confidence drops but it isn't zero. As we get more detail the fuzzy image that is the current forecast starts to come into focus and increases confidence. This is a great time to start planning as we close out the week and head into the weekend and create a plan for Monday just in case.

***Tuesday through Friday***

Cold front from Monday pushes through Tuesday morning and stalls out across the Tennessee Valley as the upper pattern become more zonal through the end of the week. Currently our forecast keeps a chance of precipitation every day through the end of the week but I anticipate there to be more dry than wet. We will also see cooler temperatures. Highs will go from the mid/upper 70s on Tuesday and keep getting cooler each day with potentially highs in the 60s by the end of the week.

AVIATION /18Z TAFS THROUGH 00Z SUNDAY/

Issued at 142 PM EDT Fri Apr 24 2026

Scattered showers and thunderstorms will approach HNB/SDF/BWG this afternoon and evening, with brief IFR/MVFR visibility and gusty winds possible in stronger cells. Otherwise, VFR conditions are expected to continue this afternoon and evening with breezy SW winds gradually diminishing by around sunset this evening. Tonight, a cold front will attempt to pass through the region, though it is expected to slow down as it crosses from west to east. As a result, low-level moisture pooling along the front may lead to low stratus or mist/fog late tonight into early Saturday morning, especially at LEX/RGA/BWG. Scattered showers will also be possible overnight; however, these are not expected to be particularly impactful. By the end of the current TAF period, winds will begin to veer to the north across the area. Saturday morning, MVFR stratocu should begin to lift from NW to SE, with VFR conditions expected at all sites by Saturday afternoon.

LMK WATCHES/WARNINGS/ADVISORIES

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