It's possible that more than 100 tornadoes hit the state of Missouri on Sunday, March 12th. If so, that would nearly double the previous record.
Update: As I suspected (but didn't write), it appears that many of these 100 tornadoes were multiple reports of the same tornadoes. See here for more information. In any case, March 12th will go down in history as the day the sky roared in Missouri.