- A tornado is a violently rotating column of air extending from a thunderstorm to the ground.

- The most violent tornadoes are capable of tremendous destruction with wind speeds of 250 mph or more. Damage paths can exceed one mile wide and 50 miles long.

- The average tornado moves from southwest to northeast, but tornadoes have been known to move in any direction.

- The average forward speed of a tornado is 30mph, but may vary from nearly stationary to 70 mph.

- While tornadoes can occur throughout the year, the peak season in Ohio is April through July.

- Tornadoes usually occur between 2 p.m and 10 p.m, but have been known to occur at any hour of the day.

- Tornadoes can be classified into one of three types:

Weak Tornadoes (F0/F1) account for 70 percent of all tornadoes; cause less than 5 percent of tornado deaths; lifetime is usually one to 10 or more minutes; wind speeds are less than 113mph.

Strong Tornadoes (F2/F3) account for 29 percent of all tornadoes; cause nearly 30 percent of all tornado deaths; may last 20 minutes or longer; wind speeds are 113mph to 206 mph.

Violent Tornadoes (F4/F5) account for only one percent of all tornadoes; cause 70 percent of all tornado deaths; May last for one hour or more; wind speeds are greater than 260 mph.

- The Fujita tornado scale (F scale) was developed by the late Professor Theodore Fujita of the University of Chicago to classify tornadoes according to wind speed and damage.

- Ohio averages 16 tornadoes and five tornado-related fatalities per year.

- In 2003, there were 12 tornadoes in Ohio resulting in 18 injuries and no deaths.

- National Weather Service (NWS) offices in Wilmington and Cleveland, Ohio; Pittsburgh, Pennsylvania; Charleston, West Virginia; and Syracuse, Indiana provide warnings for Ohio.

- The NWS uses Doppler weather radar to detect the air movement within thunderstorms. Early detection of increasing rotation aloft within a thunderstorm can allow lifesaving warnings before the tornado forms