textproduct: Louisville

KEY MESSAGES

* Scattered showers are possible today, with the highest chances (40- 60%) between sunrise and early afternoon. A stray storm cannot be ruled out, but severe weather is not expected.

* Well-above normal temperatures continue 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 remains low.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 338 AM EDT Mon Apr 13 2026

Today and Tonight...

A mid-level shortwave is crossing the Midwest early this morning and is expected to continue off to the northeast later today. A 50-55 kt H85 jet associated with this wave extends from the Ohio Valley northward into the Great Lakes, and this southerly jet is attempting to moisten what is a very dry antecedent column across southern IN and central KY. Top-down saturation will continue later this morning, with HREF mean PW values expected to increase from less than 1" to 1.3-1.5" across the area later today. Between now and sunrise this morning, a low-level theta-E surge across southern IL and central IN will attempt to initiate scattered convection, some of which could drift across our northern counties this morning. A lack of deeper moisture farther to the southeast should cause any convection to weaken, so not expecting more than showers with a few rumbles of thunder possible. While the stronger 850 mb flow remains over the area, any showers could pull down 30-40 mph wind gusts, with this potential expected to diminish after sunrise.

Later today, while the stronger forcing associated with the mid- level shortwave will be lifting well to the northeast of the area, the moisture plume brought into the Ohio Valley by this wave should linger overhead. As a result, while overall forcing and instability is very modest, hi-res guidance depicts isolated to scattered showers, with the greatest coverage expected between sunrise and early afternoon. 0Z HREF QPF localized prob.-matched mean suggests that most locations which receive rain today should see less than a few tenths of an inch, with "winners" receiving as much as half an inch. By mid-afternoon, a lack of a reinforcing shot of forcing/moisture should allow some of the moisture to mix out with daytime heating, limiting precipitation chances. However, we'll carry a 10-20% chance for a shower/storm into the evening for any isolated cells which could form thanks to differential heating.

With the increased moisture and cloud cover today, we expect temperatures to take a small step down, with highs in the upper 70s and low 80s. South-southwest winds will be breezy through the day, with sustained 10-15 mph winds and gusts of 20-25 mph expected.

Tonight, most if not all lingering diurnal cu should clear with scattered mid- and high-level clouds expected overnight. Mild southerly flow is expected to continue, though winds should be less gusty after sunset. Low temperatures will struggle to cool, with lows Tuesday morning expected in the 60s in most areas.

Tuesday - Tuesday Night...

No significant changes are expected in the synoptic pattern as we head into Tuesday, with warm SW flow continuing across the Ohio Valley. The most likely forecast for Tuesday (80-90% confidence) features dry conditions, as the upper ridge over the SE US is expected to limit convection in spite of elevated llvl moisture (HREF mean dewpoints in the low-mid 60s). However, there is a low chance for a few showers/storms to form in/near the northern CWA depending on what happens with upstream convection over the Great Lakes tonight. If storms are able to push farther south into Indiana before weakening Tuesday morning, there could be enough forcing along residual outflow boundaries to initiate isolated storms Tuesday afternoon. Short-range progs show 1500-2000 J/kg MLCAPE across southern/central IN Tuesday afternoon, though without notable forcing, the sounding profile would be capped.

Otherwise, tomorrow will be very warm with breezy S/SW winds again expected. Mostly sunny skies should allow temperatures to warm into the mid 80s, with a few upper 80s possible along/west of I-65. Rinse and repeat Tuesday night as light S/SW winds should continue overnight, keeping low temperatures in the mid-to-upper 60s in most locations Wednesday morning.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Issued at 338 AM EDT Mon Apr 13 2026

Wednesday - Thursday Night...

An upper-level trough will move from the SE CONUS towards the central Plains Wednesday and to the upper Midwest Thursday. Numerous showers and thunderstorms are expected to develop ahead of the trough axis, as well as along the associated surface low's cold front. The first wave will begin to move over the Ohio Valley early Wednesday morning, though the main core of activity will remain to our north. Chances during the morning are fairly low (15-20% for southern Kentucky and less than 15% for Kentucky), though will increase in the afternoon as diurnal heating allows for more showers and scattered thunderstorms to develop. Chances for showers will slightly increase over northern Kentucky and southern Indiana (20- 30%), with the rest of the CWA remaining below 15%. Southwesterly winds will keep our temperatures warm, with highs in the mid 80s.

As the pre-frontal showers and storms depart to over northeast, activity Wednesday night will be calm, with lows only dropping into the mid-to-upper 60s. The cold front will move in from the west early Thursday morning, along with decaying showers and thunderstorms, some of which may be gusty. The line will move across the region before departing to our east Thursday night, with LREF guidance having the area get between 0.20" and 0.30" out of this event. Temperatures will be cooler even with winds continuing to prevail from the southwest, with highs in the upper 70s. Thursday night lows will also be cooler, dropping into the low 60s.

Friday - Monday...

The SE CONUS ridge re-establishes itself on Friday as the upper low departs to the east, with warm southwesterly flow returning to the region. Highs will jump back into the upper 80s during the afternoon, and conditions will be mostly dry. A small shortwave will move over the Ohio Valley Friday night that could skirt the northwest portions of our CWA, providing a quick round of showers and a few thunderstorms.

The next point of concern comes on Saturday as the cold front of a strong surface low over the northern Plains moves towards our region, providing another round of showers and thunderstorms. The progression of the front will mainly be dependent on when the SE ridge gives way to the system, letting it progress eastward. Guidance is still uncertain on the timing of the frontal passage, with some models being more progressive and having it enter the area late afternoon, with other models being much slower and having it move through after sunset. This will be something we continue to monitor as the week progresses, as the timing will play a role on how warm we get and the intensity of those showers and storms as they move through.

Much calmer and cooler conditions follow behind the front, with dry weather expected for the remainder of the forecast period. Temperatures on Sunday and Monday during the afternoon will only get into the mid-to-upper 60s, with lows in the low 50s Saturday night and dropping into the low 40s Sunday night.

AVIATION /12Z TAFS THROUGH 18Z TUESDAY/

Issued at 715 AM EDT Mon Apr 13 2026

Increasing moisture over the region this morning will cause ceilings to lower through midday. Confidence is increasing in continuing VFR conditions with ceilings around 3-6k ft, though HNB and SDF could come close to MVFR CIGs for a few hours this morning. A few light showers will be possible this morning, though impacts to CIGs/VIS are unlikely from these showers. Winds and gusts will increase out of the S/SW later this morning, with sustained winds of 10-15 kt and gusts of 20-25 kt expected through the day. This afternoon, isolated TSRA may try to develop near HNB/BWG; however, confidence is low at this time. Tonight, VFR conditions are expected with winds becoming less gusty after sunset. Another round of LLWS is possible late tonight, especially at HNB and SDF.

LMK WATCHES/WARNINGS/ADVISORIES

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