Fresh off of Wednesday’s calamity in Oklahoma City involving supercells and tigers, the region is preparing for another two full days under the threat of a significant, multi-day tornado outbreak. Some of the tornadoes that form on Friday and Saturday could be intense and long-lived, accompanied by hail larger than baseballs and destructive wind gusts.

At this moment three years ago today, a large EF-4 tornado was getting ready to tear through Tuscaloosa, Alabama. The storm stayed on the ground for over 80 miles, tearing through Tuscaloosa and the Birmingham suburbs, killing 64 people and injuring over 1,500 more. The outbreak was the most prolific in recorded history (producing 358 tornadoes in 4 days) and most violent ever recorded in the southern United States.