April 3
edit1974: The Super Outbreak, one of the most severe tornado outbreaks in world history, spawned 148 tornadoes, including 30 violent tornadoes, in the east-central United States and Windsor, Ontario, Canada. More than 300 people were killed, and $3.5 billion (2005 USD) in damage was reported.
2012: A tornado outbreak struck the region around the cities of Dallas–Fort Worth, Texas, causing more than US$1 billion in damage.