An area of low pressure was in place across northeastern Illinois during the afternoon hours on Thursday, August 1, 2024. An associated warm front lifted across the Ohio Valley from late morning into the afternoon, allowing for an influx of hot, moist air across the region. By late morning into midday, a line of damaging storms developed across Illinois ahead of the cold front and moved across southern Indiana and Kentucky through the afternoon into the evening. The Storm Prediction Center issued a Severe Thunderstorm Watch around 1 pm CDT for the aforementioned areas.

As the line of damaging storms moved across southern Illinois, southern Indiana, and Kentucky, multiple Severe Thunderstorm Warnings and Tornado Warnings were issued. By the time the storms ended that evening, over 100 damaging wind reports had been received.

Further north, heavy thunderstorms developed across central Indiana, around the Indianapolis area. These storms were slow-moving to nearly stationary at times. As these storms tapped into a very moist environment, several inches of rain fell locally across central Indiana, prompting Flash Flood Warnings. Areas near Noblesville, Indiana, received 5.28 inches of rain in a very short period.

On the northeast side of Indianapolis, over 2 inches of rain fell. This quickly caused significant ponding and flooding. Interstate 465 on the northeast side of Indianapolis rapidly flooded, making the road impassable and causing some motorists to get stranded in the floodwaters!

A late summer heat wave occurred across portions of the Midwest on August 26-27, allowing a dangerously hot and humid air mass to build across the region. Afternoon heat index values soared above 100° F for many locations.

Aloft, an anomalously strong upper-level ridge built across the Midwest on August 26-27. Under this ridge, a dangerously hot and humid airmass was in place. As moisture surged in from the south, pooling in the anomalously warm air, dew points climbed into the 70s to even low 80s! This caused 100-115° heat indexes across portions of Minnesota, Iowa, Illinois, Wisconsin, and Missouri on August 26. On August 27, the heart of the heat shifted east across eastern Iowa, Illinois, Missouri, Indiana, and southern Michigan, where heat indexes once again climbed to around 105-120°! Many daily record high temperatures were broken across the region during this time!

An area of low pressure moved across Minnesota throughout the day on Thursday, August 29. A warm front moved across Minnesota and portions of Wisconsin, followed by a trailing cold front. In the warm sector of the storm system, warm air and dew points surged in on a southeast flow. The warm, humid air mass created significant instability for afternoon thunderstorms.

Severe thunderstorms developed ahead of the cold front across central Minnesota around 1:30 pm CDT, turning severe by 2:30 pm. As damaging winds moved through, multiple Severe Thunderstorm Warnings were issued for the Twin Cities area. Several Tornado Warnings were issued across Minnesota and western Wisconsin. In total, 10 tornadoes were reported. Multiple instances of wind damage occurred across the region, with large trees toppled over, powerlines downed, and even flipped campers!