textproduct: Louisville

KEY MESSAGES

* Hot and humid conditions will continue this afternoon and into the weekend. Afternoon temperatures will climb into the upper 80s and lower 90s with heat indices in the 105-110 range. Extreme Heat Warning will continue through this evening. A Heat Advisory will be in affect late tonight through Saturday evening.

* A few scattered showers/storms will be possible across the region this afternoon. A few strong storms are possible with gusty winds, heavy rainfall, and intense lightning being the main threats. Thunderstorm coverage will be a little higher on Saturday and Sunday.

* Scattered storms linger on Monday with spotty coverage Tue-Wed. Storm chances increase again by late week with highs remaining in the upper 80s to low 90s.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 314 PM EDT Fri Jul 3 2026

It was another hot and humid day across the region. Afternoon temperatures have warmed into the lower 90s. Dewpoints were in the mid-upper 70s and this was producing heat indices in the 105-110 degree range. Visible satellite imagery shows the center of the mid- level anticyclone over northern Kentucky this afternoon. Stronger convergence and weaker capping has led to the development of an arcing band of convection from our southwest CWA northwestward toward Owensboro and then northeast into southern Indiana. Additionally strong heating over the urban heat islands has led to some showers and weak storms that fired over Louisville and Lexington earlier. Current environment features a highly buoyant airmass with very weak shear. The convective character is pulse- type with wet microbursts, heavy rainfall, and intense lightning. The overall environment is not expected to change through the afternoon hours.

For the remainder of the afternoon, convection looks to be focused over our southwest/WABBLES area and across our northwest and northern CWA. Strongly buoyant atmosphere with weak steering currents will allow strong storms to develop with gusty winds and heavy rainfall. The weak cell motions will lead to the possibility of flash flooding where storms just sit. Storms that develop a stronger cold pool and outflow may propagate a bit better resulting in a lower threat of flooding. Earlier convection over our northwest CWA has produced an outflow boundary that will continue to move east-southeast across southern IN. This may be enough to produce some additional convection through the afternoon. However, as one gets along and east of the I-65 corridor, mid-level capping does increase a bit. For now, have gone ahead and increased afternoon PoPs across southern IN and into the Louisville Metro and also increased PoPs down in the Bowling Green area. Afternoon highs will top out in the lower 90s.

For this evening and tonight, look for convection to diminish rather quickly with the setting sun. Temperatures will fall into the 80s this evening before cooling in the mid-upper 70s for the overnight period. Areas that see appreciable rainfall this afternoon could drop into the lower 70s for lows offering some relief. The urban heat islands will remain the warmest with upper 70s and perhaps even low 80s for lows. We will let the Extreme Heat Warning go at 900 PM EDT and it will be followed up with a Heat Advisory that will continue overnight and into Saturday. Convective trends overnight will continue to be monitored. There are a few signals showing up that upstream perturbations aloft could force some additional convection overnight. For the most part, much of the overnight looks to remain dry, but some convection may fire up toward dawn Saturday. Patchy fog will be possible once again overnight in the low-lying and typical fog prone areas. Also areas that see appreciable rainfall will have a higher chance of locally dense fog overnight.

For Saturday, upper level ridge axis will shift eastward into the Mid-Atlantic region. We'll see height falls across the region that will result in lower high temperatures across the region. Mid-level capping will be noticeably weaker and convective coverage looks to be a bit higher across the area during the afternoon and evening. There is not a large amount of synoptic scale forcing for convection on Saturday. So convection will likely be driven by differential heating and leftover mesoscale boundaries. Strong to severe convection is possible once again as MLCAPE values rise int the 2500- 3000 J/kg range. However, shear across the region will remain rather weak. Therefore, another day of pulse-type convection is expected. Wet microbursts, intense lightning, and heavy rainfall will be possible with any of the storms. Afternoon highs will be cooler with upper 80s to around 90 expected. A moist airmass will remain in place which will help produce heat indices in the afternoon to rise into the upper 90s to the lower 100s. Look for convection to diminish with the setting sun Saturday evening with lows in the 70s.

For Sunday, a weakening frontal boundary will drop into the region from the north and should provide the region with a focus for renewed convective development during the daytime hours. Afternoon highs in the upper 80s to around 90 are expected. Dewpoints will remain high across the region and may produce heat index readings again into the upper 90s/lower 100s. Confidence in exceeding advisory criteria preclude extending the Heat Advisory into Sunday. This is due to the anticipated higher convective coverage and cloud cover which may reduce overall high temperatures. The atmospheric profile will remain highly buoyant with weak shear providing another day of pulse-type storm coverage with damaging winds and lightning being the main threats. Flash flooding risk may be more elevated Sunday as overall coverage of storms increase and there may be more of an enhancement of training across the region. Look for convective coverage to wane again toward sunset with overnight lows in the 70s.

LONG TERM /MONDAY THROUGH FRIDAY/

Issued at 314 PM EDT Fri Jul 3 2026

===== Monday - Friday =====

By Monday morning, low pressure over southern Canada will stream off towards the east, dragging in a trailing cold front that will slowly move through the Ohio Valley in the afternoon. Though total atmospheric flow will remain weak, PWATs and weak general lifting from the front will allow for scattered afternoon storms to fire off. Generally scattered convection will prevail, though a broken line of storms along the best lift from the front may move in from the NW. Though confidence is low on a prominent line, showers and storms in the afternoon will be scattered across the whole area. Good news is that with continued weak shear despite modest SBCAPE values of 1,500 - 2,500 J/kg, severe risk seems limited despite the threat of gusty winds with typical summertime convection. PWATs will range in the 1.7-1.9" still, meaning any storms have the potential to bring heavy downpours in the afternoon. Rainfall totals for Monday according to HREF ensemble guidance suggests a 50-75% chance of receiving 0.25-0.5", though localized areas of 1-2" are possible. A marginal risk of excessive rainfall has been issued for the whole area for this localized threat of flash flooding from storm, though this threat will be limited by storm coverage. Highs will vary based on rain coverage as well, trending towards the mid to upper 80s. Lingering storms will wane as nocturnal cooling takes over as the weak cold front slowly stalls over central/southern KY. PWATs will decrease in areas behind the front though uncertainty remains how far this front will advance to the south.

Tuesday morning temperatures remain mild in the upper 60s to low 70s. South of the front convection will refire once again and be more concentrated in areas near the southern border with TN or further south depending on the timing of the front. As this boundary remains nearly stationary, pulses of energy will ride along the front and aided with daytime heating to bring daily storm chances through the week. Tuesday afternoon's storms will be widely scattered especially across our south with just spotty storms in the north and highs remaining nearly the same in the mid to upper 80s.

Wednesday the front may sag far enough south where most storms remain out of the area. Though a storm or two can't be ruled out with highs remaining in the upper 80s. Eventually, a more prominent trough from Canada will swing far enough south to issue in more showers and storms Thursday through Friday. This will be our next widespread rainfall event as PWATs surge with an incoming shortwave. Shear might uptick a bit from the trough from Canada, leading to the potential for more organized convection. Highs remain in the upper 80s to low 90s by the end of the week.

AVIATION /00Z TAFS THROUGH 06Z SUNDAY/

Issued at 749 PM EDT Fri Jul 3 2026

As we continue to lose the daytime heating showers and thunderstorms will continue to diminish and decrease into the overnight. This will continue to give us mainly VFR flight categories through the overnight. The only challenges and potential impacts overnight are lingering showers and storms just around the BWG at the start of the forecast period and then some MVFR VIS for a few sites early in the morning.

Put in a PROB30 for SDF as there appears to be some consistent model agreement of a cluster of showers and storms forming across southern IN just after daybreak. Then after that the challenge will be more scattered to isolated showers and storms are likely in the afternoon tomorrow but confidence in location is low in these type of daytime heating time thunderstorms. Went PROB30 for TAF sites tomorrow afternoon.

LMK WATCHES/WARNINGS/ADVISORIES

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