List of tornado outbreaks by outbreak intensity score

In late 2023, American meteorologist and tornado expert Thomas P. Grazulis created the outbreak intensity score (OIS) as a way to rank tornado outbreaks. For the score, only significant tornadoes are counted: F2/EF2 tornadoes receive 2 points each, F3/EF3 tornadoes receive 5 points each, F4/EF4 tornadoes receive 10 points each, and F5/EF5 tornadoes receive 15 points each. The number of total points determine the rating for the outbreak, which is broken up into seven categories.

Super outbreaks
There have been two tornado outbreaks which scored more than 250 points on the OIS, reaching the status of "super outbreak".

Historic outbreaks
There have been 24 tornado outbreaks which scored at least 120 points, but less than 249 on the OIS, reaching the status of "historic outbreak".

Devastating outbreaks
There have been several tornado outbreaks which scored at least 80 points, but 119 or less on the OIS, reaching the status of "devastating outbreak".

Major outbreaks
There have been several tornado outbreaks which scored at least 30 points, but 79 or less on the OIS, reaching the status of "major outbreak".