|Credit: National Oceanic and Atmospheric Administration|
Spring always brings tornado season, especially to the American Midwest and South, as yesterday's flurry of twisters in Oklahoma demonstrated. But on April 4, 1974, something far rarer and more dramatic struck the eastern U.S. That day brought more tornado strikes than any in recorded history, and tragically, also had more tornado-related deaths than any other day.
The event is now known as the Super Outbreak. The first tornadoes touched down late on April 3 and the storms continued throughout the next day, with some twisters still forming on April 5. During the most intense 24-hour period, 148 tornadoes claimed 315 lives, trailed across a total of 2,598 miles (4,181 km) and caused $6 million in damages, according to the National Oceanic and Atmospheric Association (NOAA) official report on the incident. In today's dollars, that amounts to $26.5 million in damage, according to the Bureau of Labor Statistics.
During the course of the outbreak, the U.S. government declared 10 states disaster areas, and Ohio, Kentucky and Alabama witnessed the most violent tornado strikes in recorded history, the NOAA report said.
It was your ultimate set up. It had the ingredients of lots of instability in the atmosphere, and lots of wind-shear to help organize the storms , said Harold Brooks, a research meteorologist at the National Severe Storms Laboratory. Easily the most F4s and F5s we've ever seen in history. (Tornadoes are rated on a scale from F1 to F5, with F5 tornadoes being the fiercest.)
The Super Outbreak began, like many tornado outbreaks, when warm, moist air traveling north from the Gulf of Mexico moved under cold, dry air moving east off the Rocky Mountains, Brooks told Life's Little Mysteries. However, on April 4, the cold front from the Rockies was bigger than ever before, and the moisture in the air coming from the Gulf of Mexico provided the energy to fuel the Super Outbreak, Brooks said.
Meteorologists predicted the Super Outbreak well in advance and used improved communication channels, that had been implemented after the deadly Palm Sunday tornado strikes more than a decade earlier, to disseminate those predictions, Brooks said. On Palm Sunday, 1965, tornadoes almost as strong as those of the Super Outbreak had battered the Midwest and killed 250 people, according to the NOAA. The accurate and widely-communicated predictions of the Super Outbreak helped mitigate damage from the storm, Brooks said.
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