July 15, 2024: Derecho Produces Widespread Wind Damage and Numerous Tornadoes

The National Weather Service continues to add tornadoes to the list from July 15.  The severe weather breaks the previous daily record for tornadoes. The record was 22 and now it’s at least 31. The latest in our area to get the designation is Mokena, originally described as having straight line winds, is now designated a tornado, with an EF-0 rating.

Overview

Summary:

• During the evening hours of July 15, a well-organized and long-lived complex of thunderstorms (officially classified as a derecho) rolled across Iowa, Illinois, and parts of Indiana. Widespread damaging winds of 60 to locally 100 mph were observed within the line, especially from eastern Iowa through northern and central Illinois. In addition, at least 31 occurred in the NWS Chicago County Warning Area.

• With 31 tornadoes, this storm breaks the previous daily record for tornadoes in our forecast area. This record was originally 22, set during the June 30th, 2014 “Double Derecho” event and later tied by March 31, 2023 Tornado Outbreak). See the tornadoes tab for more information on these tornadoes.

• The derecho was the 5th thunderstorm event to occur within the span of around 60 hours in northern Illinois and northwestern Indiana, and was the “finale” of an active “Ring of Fire” pattern. Ring of Fire patterns are characterized by episodic clusters of thunderstorms that parade around a dome of heat. They typically occur every summer, but vary in severity and cadence with each year.  To see the full list and the path of the tornado click below.

National Weather Service