textproduct: Louisville

KEY MESSAGES

* Temperatures will continue to trend down over the next few days. Highs this afternoon will top out in the upper 80s to near 90 with heat indices in the 98-104 range. The Heat Advisory will continue into the evening hours.

* A few isolated storms could develop across the region this afternoon, mainly west of I-65. Overall, most locations will remain dry this afternoon and this evening.

* Scattered showers and storms may also develop during the day on Sunday. A few storms could be strong with gusty winds, heavy rain, and lightning.

* More seasonable temperatures and intermittent rain chances are expected for the upcoming week.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 318 PM EDT Sat Jul 4 2026

Afternoon satellite and observations show mostly sunny skies across the forecast area this afternoon. Temperatures were notably cooler with afternoon temps in the upper 80s. Still have a few more hours of heating and most sites will top out in the upper 80s with a few hitting 90. Dewpoints continue to recover across the region after being mixed out last evening. With dewpoints rising into the low- mid 70s west of I-65 and into the upper 60s east of I-65, we'll see afternoon heat indices topping out in the low-mid 90s over much of the region with upper 90s and lower 100s being regulated to the I- 165 corridor and points west. We should see a diurnal Cu field continue develop across the region with a few-sct deck around 4-5KFt AGL, but this will mix out later this evening.

Convection is going to be quite limited across much of the region this afternoon and evening. We've got a bit of subsidence in the wake of all the overturning that took place last night with the gust fronts scouring out the low-level moisture. We're also lacking a forcing mechanism other than just differential heating. However, we're likely not going to hit the convective temperature in areas east of I-65. The exception will be out over in the higher dewpoint air west of I-165 where a few isolated-scattered storms could develop over the next few hours. Any storm that develops will be capable of gusty winds, heavy rainfall, and lightning.

For tonight, any scattered convection will diminish with the setting sun as the PBL begins to stabilize. However, later in the overnight, a weak frontal boundary and upper level wave will move toward the region and may provide enough lift to produce some scattered showers and storms late tonight. Otherwise, look for lows to fall into the lower-middle 70s.

For Sunday, still anticipate mid-upper level heights will continue to decrease across the region with a surface frontal boundary gradually dropping southward into toward the area. Strong moisture advection will be seen across the region with PWAT values rising into the 1.7- 1.8 inch range. Risk of severe weather continues to look rather low across the region. Looking at soundings, we have more of a skinny CAPE profile, weak shear, and weak low-mid level lapse rates. This would probably tend to lessen the chance of wet microbursts. However, a couple of strong storms can't be ruled out with gusty winds, heavy rainfall, and lightning.

We are expecting a bit more storm coverage tomorrow and an increase in overall cloud cover which will limit incoming radiation and keep temperatures a bit cooler. Went closer to the bias-corrected short term guidance here with highs in the upper 80s to near 90. Peak heat index readings will likely fall short of advisory level, so we have no plans on going with another headline at this time.

By Sunday night, we should see the front push a little more south across the region. Uncertainty remains high here if the front will make it all the way through the region. With the onset of nocturnal cooling, we should see convective storm coverage diminish. Lows again will be in the low-mid 70s.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 318 PM EDT Sat Jul 4 2026

Moving into the new work week, we'll see a gradual increase in mid- level heights over the inter-mountain west with troughing developing off shore in the Pacific. Downstream a baggy trough axis looks to set up across the Ohio Valley and into the northern TN Valley. Our aforementioned surface front from the short term will likely stall out somewhere across the region. The multi-model consensus suggests that unsettled weather is likely through at least mid-week. Model soundings from across the region continue to show a rather moist airmass in place, but wind shear values are quite week. The pattern to us resembles a typical diurnally driven convective scenario with dry mornings giving way to scattered afternoon/eve convection. Overall storm steering motions will be weak, so heavy rainfall and flooding could be an issue in some areas. Temperatures from Monday- Wednesday will be seasonal with afternoon highs in the 85-90 range and overnight lows in the 70s.

By late week, upper trough axis over the Pacific will move east and result in the downstream ridge moving slightly eastward out of the inter-mountain west and into the northern High Plains. As this occurs, the ridge will build a bit and this will re-inforce downstream troughing across the eastern US. This will result in a continued unsettled pattern for the Ohio Valley with continued storm chances. If the trough can get significant latitude southward, we may have enough a northward push to push the quasi-stationary boundary south and bring a drier pattern to the Ohio Valley by next weekend.

AVIATION /18Z TAFS THROUGH 00Z MONDAY/

Issued at 118 PM EDT Sat Jul 4 2026

VFR conditions are expected for much of the upcoming TAF period. We've got a bit of subsidence across the region this afternoon which will likely prevent much in the way of cloud cover. While moisture is returning to the region from the southwest, we may be able to squeeze out a FEW050 deck for several hours this afternoon. Winds this afternoon and into this evening will be mostly southwest to westerly. A few occasional gusts to 15-17kts will be possible.

For tonight, convective coverage remains challenging. A frontal boundary will move eastward toward the region after sunset. This may bring a round of showers/storms to our northwestern area. For now will keep a PROB30 of TSRA over at HNB.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Heat Advisory until 9 PM EDT /8 PM CDT/ this evening for KYZ023>043-045>049-053>057-061>067-070>078-081-082. IN...Heat Advisory until 9 PM EDT /8 PM CDT/ this evening for INZ076>079-083-084-089>092.