23 years ago today the most powerful August tornado to strike the United States ripped through the southwest suburbs. The Plainfield tornado killed 29 people and injured over 350 others.
The storm that spawned the tornado developed first in southern Wisconsin and then moved southeast across the state line towards Plainfield and Joliet. Most tornados tend to move from the southwest to the northeast. The movement of the storm wasn’t the only thing unusual about it though. The Chicago office of the National Weather Service noted several things that made this tornado unique:
- It was the first ever rated greater than F3 in August in the state of Illinois.
- It was only the second killer tornado to occur in Illinois during the month of August.
Twenty-three years later it remains the only F5/EF5 tornado ever documented in the U.S. during the month of August. In fact, only 0.2% of all tornadoes in August have been rated F4/EF4 or greater.
The tornado was shrouded by low clouds and rain, making it difficult to see. As a result, no known photographs or videos of the tornado exist.
- It is the only F5 tornado to strike in the US during the month of August.
It is the 15th most damaging tornado between 1890-1990 according to the National Severe Storms Laboratory ranking. It left a damage path over 16 miles long that was as wide as 1/2 mile at times. The visible satellite imagery (see above) from that day shows the storm growing rapidly that afternoon.