Tornado sizes are compared with measurements of the Enhanced Fujita, or EF, scale. Weak tornadoes are EF0 and EF1, strong twisters are EF2 and EF3, while violent tornadoes are EF4 and EF5. Measurement of tornado size is not the same as intensity; some large tornadoes are weak, and some small tornadoes are strong.
Tornadoes come in three basics types, including weak, strong and violent. A majority of tornadoes, 69 percent, are weak twisters with wind speeds less than 100 mph and little damage. Strong tornadoes, or 29 percent of the overall total, have speeds between 110 and 205 mph, remain on the ground for 20 minutes and knock over mobile homes. Violent tornadoes are the least common and deadliest.
Tornadoes vary in width from 10 yards to more than 2 miles. The average tornado size is 50 yards wide with a damage path of 1 or 2 miles. As of August 2014, the widest tornado ever measured hit El Reno, Okla., on May 31, 2013. The width of the EF5 tornado reached a maximum of 2.6 miles, with a damage path 16.2 miles long. The highest wind gust recorded with the El Reno twister was 296 mph. The tornado struck just west of Oklahoma City and killed 18 people.