The EF Scale and how tornadoes are rated | Weather [Video]

Since 2007, the weather community has used the Enhanced Fujita Scale to rate tornadoes based upon damage to structures and vegetation. The local National Weather Service office will conduct surveys of potential tornado damage in the hours and days to follow the storm.

While most confirmed tornadoes get rated, a small fraction of them go unrated and will be considered an EF-Unknown (EF-U). Otherwise, the ratings for tornadoes go from EF-0 to the rare EF-5. Tornadoes rated EF-0 and EF-1 account for 75% of all tornadoes that have occurred in Oklahoma in our records. Winds up to 110 mph can be inferred from an EF-1 twister. EF-2 tornadoes account for 18% of Oklahoma tornadoes with winds between 111 mph and 135 mph. Roof and other structural damage is common in well-built structures, but most walls remain standing. An EF-3 tornado occurs only 5% of the time in Oklahoma with winds …