textproduct: Louisville

KEY MESSAGES

* Near-record warmth returns today, with well-above normal temperatures continuing throughout the upcoming week. A few temperature records may be in jeopardy.

* Intermittent chances for showers and storms are expected this week. Best chances for rain and highest rainfall totals are favored along and north of the Ohio River and points northwest. Strong storms are possible Thursday and next weekend, but the probability and confidence remains low.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 339 AM EDT Sun Apr 12 2026

Much warmer temperatures return today as our weak frontal boundary over the KY/TN border has lifted to the north. Even with the sfc high also retreating to our north, the upper-level ridge over the SE CONUS will allow us to remain dry throughout the day. The placement of the sfc high off the New England coast and a sfc low over the upper Midwest will set up a pressure gradient over our region by mid- morning, resulting in breezy southwesterly winds during the afternoon hours. Sustained winds of 10 to 15 mph and gusts of 20 to 25 mph are forecast, decreasing by the evening hours. Temperatures this afternoon will get into the low-to-mid 80s that could flirt with our record highs in Louisville (87) and Lexington (85).

Low level mixing will be impactful for both our temperatures and dew points today as some drier air could mix down. The combination of low RH values from the mixing, well above average temperatures, gusty winds, and severe drought in the southwest portions of our CWA gives some concern for elevated fire weather conditions. HREF guidance continues to put us under a layer of upper clouds this afternoon that would limit the extent of deeper mixing and reduction in RH values. We will issue a Fire Weather SPS shortly to further message our concerns for conditions this afternoon.

The upper ridge breaks down slightly tonight, allowing a weak cold front to move over the area through Monday morning. The front will have to combat the dry air from Sunday, so the highest chances for scattered showers and a few thunderstorms (50-60%) will be across the northwest portions of our CWA. Winds will still be elevated out ahead of the front, and the combination of that and increasing cloud cover will only have temperatures drop into the mid- to-upper 60s that could threaten record warm minimums for Louisville (69), Lexington (64), Bowling Green (67), and Frankfort (63). Afternoon highs will be slightly cooler than Sunday, only getting into the upper 70s/low 80s as the frontal boundary lingers over the region. A few showers and storms could form late Monday night with the lingering front, though chances right now are low (< 15%). Monday night lows will again be in the mid-to-upper 60s, continuing the theme of potential record-setting conditions across the region.

LONG TERM /TUESDAY THROUGH SATURDAY/

Issued at 339 AM EDT Sun Apr 12 2026

During the mid-week period and into the first half of next weekend, a fairly consistent synoptic pattern is expected over the CONUS, with LREF ensemble mean 500 mb heights depicting persistent high heights/ridging across the southeast US. In contrast persistent low heights/troughing is expected over the western CONUS, with broad SW flow extending from the desert SW across the Plains and into the northeast US.

Within this SW flow regime, a couple shortwaves will eject across the central US, bringing showers and storms as each system passes. The Ohio Valley is expected to be on the southern edge of the average storm track, and while there will be intermittent chances for showers and storms through the week and into next weekend, total rainfall amounts and strong/severe storm chances should be generally greater to the north and west of the area.

ECMWF Extreme Forecast Index values for temperatures now exceed 0.9 for much of the period Tuesday through Saturday, indicating high confidence in anomalously warm temperatures. Several days also feature shift of tails values of 1-2, indicating at least the potential for higher-end anomalies which could approach or break daily temperature records.

--------------------------------------------------------------------- Tuesday - Thursday Night...

Tuesday into Wednesday, the bulk of the chance for showers and thunderstorms is expected to remain north and west of the area as the southeast ridge keeps the best forcing and moisture out of the area. However, showers and storms which initiate where ingredients are more favorable across Illinois and northern/central Indiana could spill into our northern counties, though any activity should be weakening as it encounters a less favorable environment. As a result, there is a low-medium chance for showers and storms (20- 50%) in the forecast at this time across northern portions of the CWA, though this may decrease as high-res guidance provides additional confidence in coming days. Tuesday and Wednesday should provide a decent chance at approaching record warm max and min values, with highs in the mid-to-upper 80s and lows in the 60s.

Wednesday night into Thursday, a stronger shortwave is expected to take a deeper dig into ridging aloft, bringing a better surge of moisture across the region. Precipitation chances are expected to increase early Thursday morning, with 40-60% chances for showers and storms continuing through the day on Thursday. The potential for strong to severe storms Thursday is fairly uncertain, as deep moisture profiles (with tall, skinny CAPE) may limit instability. Machine learning guidance does show 5-15% probabilities for severe convection Thursday across the Ohio Valley, though this is relatively unimpressive compared to recent higher-impact severe events. The increased cloud cover and precipitation should keep temperatures lower on Thursday, with upper 70s and low 80s being the most likely range for high temps.

Friday - Next Weekend...

Another upper trough is expected to dig across the intermountain West on Friday, leading to downstream height rises and warmer temperatures across the eastern CONUS. While there is a low (10-20%) chance for showers/storms in the current forecast for Friday, if ensemble solutions converge on the current deterministic solution, would expect Friday to be a dry and quite warm day. Friday may be our best chance to hit 90 degrees over this forthcoming warm spell, especially across southern KY.

Friday night into Saturday, the trough over the western CONUS is expected to eject across the central CONUS, with an associated cold front/low pressure system pushing east during this period. This puts Saturday's forecast into some doubt at this time. If the system trends slower and the ridge over the southeast US holds on for longer, Saturday may also end up warm and dry. However, a faster system/weaker ridge could lead to showers and storms developing across the Ohio Valley, especially by Saturday evening. By the second half of the weekend, the cold front is expected to push through the region, potentially bringing another chance for showers and storms, some of which could be strong. A cool-down and limited rain chances would be expected for a few days after this system passes.

AVIATION /12Z TAFS THROUGH 18Z MONDAY/

Issued at 723 AM EDT Sun Apr 12 2026

VFR conditions will continue for most of the TAF sites, with the exception of BWG that continues to have brief periods of lower visibility due to patchy fog. This will only last for a couple more hours before winds across the region increase and shift to the southeast mid-morning. Sustained winds around 10 to 15 mph and gusts up to 22 to 25 mph will be likely Sunday afternoon before decreasing after sunset. A LLJ will move through the region late Sunday night that could cause a period of LLWS after 06z Monday across all the terminals, lasting until around 12z. A line of showers and a few isolated storms will enter the region from the northwest, moving eastward through the remainder of the TAF period. Ceilings will decrease, but are currently expected to remain at VFR levels throughout.

LMK WATCHES/WARNINGS/ADVISORIES

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