Definitions by Brian
Tornado that is rated: (strong) with winds from 113-157 mph, causing: CONSIDERABLE DAMAGE: Roofs blown off homes leaving strong walls standing. Sheds and other outbuildings demolished, unanchored mobile homes overturned, block structure walls collapsed, roofs peeled back. Small wood missiles observed.
a Tornado rated: (violent), with winds from 261-318 mph, causing (RARE) INCREDIBLE DAMAGE: Homes on slabs levelled with debris removed. Schools, motels and other marginally engineered buildings have considerable damage with exterior walls and roofs gone. Top stories demolished.