Under the Enhanced Fujita scale, there are seven categories of storm. The lowest category is EFU, which is used for storms that don't have enough data or cause enough damage to be classified.

The strength of tornadoes is rated on the Enhanced Fujita, or EF, Scale. Storm chasing photographers take photos underneath a rotating supercell storm system in Maxwell, Nebraska on September 3, 2016.

Fujita Scale: This scale rates tornadoes based on the damage they cause to structures like buildings, trees, and other objects. However, it used general damage indicators, ...

The EF scale, better known as the Enhanced Fujita Scale, was adopted by the National Weather Service (NWS) in 2007. This scale is a revised version of what was known as the Fujita Scale ...

MOLINE, Ill. — This upcoming May will mark 10 years since the United States last saw a tornado rated an EF-5, the strongest possible rating using the Enhanced Fujita Scale. That's quite a ...

MOLINE, Ill. — A new study published by the American Meteorological Society has shed light on a puzzling phenomenon: The United States has not logged an EF5 tornado, the most violent category ...

Since its inception in 2007, the Enhanced Fujita Scale no longer depends solely on wind speeds to determine the strength of a tornado. The last recorded EF-5 tornado was observed in Moore, Oklahoma, ...