textproduct: Louisville

KEY MESSAGES

* A few pockets of light rain will be possible (<20% chance) tonight into Monday morning, with most places remaining dry. Patchy fog will be possible across the area tonight.

* Strong upper ridge over the region will result in the hottest temperatures of the summer for all of next week. Highs in the low- to-mid 90s, dew points in the mid/upper 70s will result in heat index values above 100 to near and even above 105. A Heat Advisory is out across the entire area Monday through Thursday.

* High heat and humidity will continue into the Independence Day Holiday with the potential for isolated to scattered thunderstorm during the afternoon and evening.

SHORT TERM /THROUGH TONIGHT/

Issued at 417 PM EDT Sun Jun 28 2026

The last portion of our heavy showers and storms that produced considerable-to-significant flash flooding across the area has finally departed to the southeast. A weak frontal boundary just off to our north will become NW to SE oriented through this evening and the overnight. A few areas of very light rain could occur through the morning hours, but with the departure of the forcing mechanisms that aided all of the recent rainfall, little-to-no appreciable precipitation is expected. The latest HREF guidance only gives up to a 30% chance for rainfall greater than 0.10", and that is mainly confined to areas along and east of I-75.

For tonight, mid and upper-level ridging will begin to build in over the region and will be a key feature to pay attention to not only in the near-term, but also in the extended forecast period. Cloud cover across the area will slowly break up, with mostly clear skies expected during the late overnight hours. With all of the moisture in place from the recent rainfall, in addition to calm winds forecast tonight, patchy fog could develop across the region, with areas of fog possible in the eastern portions of the CWA. Temperatures will not fall much tonight, with morning temperatures in the low-to-mid 70s expected.

LONG TERM /MONDAY THROUGH SUNDAY/

Issued at 417 PM EDT Sun Jun 28 2026

To close off the month of June and start the month of July, we will be in a prolonged stretch of hot temperatures and oppressive humidity. A robust 594-597 dm mid/upper-level ridge builds over the eastern CONUS, which will be responsible for keeping us dry once a weak surface frontal boundary lifts off to the north on Monday. Additionally, the ridge will also be allow temperatures to climb up into the low 90s to start the week, with highs in the mid 90s possible by the middle and latter parts of the workweek. In the latest LREF guidance, probabilities to exceed 90 on Monday are greater than 70% west of I-65, and range from 40-70% to the east. Probabilities increase across the area Tuesday and Wednesday, with a greater than 75% chance. Probabilities for temperatures above 95 are low (<35%) until Wednesday, with widespread 40-60% chances being outlined Wednesday through Friday. One of the factors in place to limit our maximum temperatures, especially earlier on in the week, is the remaining moisture from our recent rainfall. As that water gets evaporated into the atmosphere, the energy needed to allow this evaporative process cools near-surface temperatures as the moisture coverts to water vapor.

While we are not as concerned about the possibility of record- breaking heat across the region, the thing that gives us the most worry will be the higher dew points that will last throughout the week. In combination with all of the rainfall we've had recently, dew points in the mid 70s will result in oppressive humidity across southern Indiana and central Kentucky, as well as our highest heat indices of the year. A Heat Advisory has been issued across the entire CWA beginning Monday at 12 PM EDT, lasting through Thursday evening. Heat indices above 105 will be likely this week, with a currently low (<15%) chance for indices meeting or exceeding Excessive Heat Warning criteria (110) later this week. Make sure to take precautions if you are outside for considerable amounts of time this week as this period of hot and humid weather persists.

By the end of the week and going into the 4th of July weekend, the upper-level ridge begins to slowly break down and shift off to the east. A few shortwaves will move over the western periphery of the ridge that could move over the region if the ridge moves far enough east. This would set up our next chance for showers and storms to develop, but disagreement in deterministic and ensemble guidance has kept probabilities of precipitation below 35%.

AVIATION /00Z TAFS THROUGH 06Z TUESDAY/

Issued at 726 PM EDT Sun Jun 28 2026

VFR conditions with few mid to high level clouds will continue this evening across the area. Overnight, a mixture of calm winds and moisture from recent rainfall could produce areas of patchy fog. Additionally, a signal for lower stratus is also possible in the early morning hours. LEX and RGA could see cigs close to MVFR briefly before lifting by tomorrow afternoon. Otherwise, winds will be light and variable overnight with predominantly SW flow tomorrow.

LMK WATCHES/WARNINGS/ADVISORIES

KY...Heat Advisory from noon EDT /11 AM CDT/ Monday to 9 PM EDT /8 PM CDT/ Thursday for KYZ023>043-045>049-053>057-061>067- 070>078-081-082. Heat Advisory until 8 PM CDT this evening for KYZ023-026-061- 070>072. IN...Heat Advisory from noon EDT /11 AM CDT/ Monday to 9 PM EDT /8 PM CDT/ Thursday for INZ076>079-083-084-089>092.