The Super Outbreak was the largest tornado outbreak on record. On April 3, 1974, 148 tornadoes hit in 13 states: Illinois, Indiana, Michigan, Ohio, Kentucky, Tennessee, Alabama, Mississippi, Georgia, North Carolina, Virginia, West Virginia and New York. One tornado also hit near Windsor, Ontario, Canada. It was the only one to hit outside the United States.

This outbreak also broke the record for most F5 and F4 (Fujita scale) tornadoes. There were six F5 tornadoes and 23 F4 tornadoes. The outbreak began in Morris, Illinois, at around 1 P.M. on April 3, 1974. As the storm system moved east where it had been sunny all day, the tornadoes became more severe. A tornado that hit near Monticello, Indiana, was an F4 and had a path length of 121 miles, the longest path length of any tornado for this outbreak. Nineteen people were killed in this tornado. The first F5 tornado of the day hit in Xenia, Ohio. It killed 33, injured 1,150, and destroyed about half of the city. Xenia was hit again by another tornado on September 20, 2000.

Five more F5s would go on to hit—one in Indiana, one more in Ohio, one in Kentucky, and two in Alabama. Twenty-eight were killed in Brandenburg, Kentucky, and 30 were killed in Guin, Alabama. The lowest number killed by an F5 tornado in this outbreak was 6 in Hanover, Indiana. During the peak of the outbreak, a staggering fifteen tornadoes were on the ground simultaneously.

There were 18 hours of continuous tornado activity. The outbreak finally ended in the early morning hours of April 4, 1974. A total of 315 people were killed in 49 killer tornadoes and 5,484 were injured.

The Super Outbreak occurred at the end of a very strong, nearly record-setting La Niña event. The 1973-74 La Niña was just as strong as the 1998-99 La Niña.

Myths debunked

The following are a few tornado myths that the Super Outbreak debunked:

• Notion: Tornadoes can't form near rivers and cross them.
• Fact: A tornado formed near Sayler Park section of Cincinnati, Ohio (near the Ohio River). It was among the six F5's of the outbreak. The city of Cairo, Illinois, which lies at the confluence of the Ohio and Mississippi Rivers was also hit by a tornado that day.

• Notion: Tornadoes can't follow terrain into steep valleys.
• Fact: After destroying three schools, the Monticello tornado crossed over a 60-foot bluff and the Tippecanoe River and damaged several homes.

• Notion: Tornadoes can't go over steep hills or mountains.
• Fact: The Guin tornado crossed Monte Sano mountain (1,650 feet) and gained in intensity as it descended the mountain. Tornadoes formed in West Virginia, western Virginia, and North Carolina, three states that are in the ranges of the Appalachian mountains.

• Notion: If a tornado is approaching, you should open your windows, or the difference in pressure will cause your building to explode.
• Fact: Flying debris from a tornado will break any windows, so opening them only wastes valuble time. It is the debris that breaks windows, not the difference in pressure.

See also

• List of tornadoes and tornado outbreaks

External links

• A website dedicated to The Super Outbreak
• The Weather Channel's Storm of the Century list - #2 The Super Outbreak
• Footage of the Louisville storm