The Enhanced Fujita Scale or EF Scale, which became operational on February 1, 2007, is used to assign a tornado a 'rating' based on estimated wind speeds and related damage.

An Enhanced Fujita (EF) Scale, developed by a forum of nationally renowned meteorologists and wind engineers, makes improvements to the original F scale. This EF Scale has replaced the original F scale, which has been used to assign tornado ratings since 1971.

The EF Scale takes into account more variables than the original F Scale did when assigning a wind speed rating to a tornado. The EF Scale incorporates 28 damage indicators (DIs) such as building type, structures, and trees.

The EF Scale was revised from the original Fujita Scale to reflect better examinations of tornado damage surveys so as to align wind speeds more closely with associated storm damage. The new scale has to do with how most structures are designed.

This tornado was part of the April 2, 1982 tornado outbreak which produced 56 tornadoes in 11 states, killing 30 persons and injuring another 383 people. This was the only F5 Tornado that occurred in the 1980's in Oklahoma.

May 25, 2008 · NWS personnel have rated the Parkersburg-New Hartford-Dunkerton tornado as EF 5 (correlated to wind speeds up to 205 MPH) on the Enhanced Fujita Scale at the locations of maximum damage. This is the first EF5 tornado in Iowa since the …

Since 1871, Iowa has had eleven F5/EF5 tornadoes (the most intense damage category on the Fujita and Enhanced Fujita damage scales - less than 1% of tornado occurrences - wind speeds greater than 200 mph).

Since 1966, only four tornadoes have produced EF-5 damage in Central Alabama. These occurred on March 3, 1966 in the Vienna and Benevola tornado, April 3, 1974 in the Guin tornado, April 4, 1977 in the Smithfield tornado and most recently April 27, 2011 in the Hackleburg and Phil Campbell tornado.

Wisconsin Tornado and Severe Weather Awareness. Part 3 - Tornado Classification and Safety. Tornadoes can occur in many different shapes and sizes ranging from a few yards to over one mile in width. They can move slowly, appearing nearly stationary, to as fast as 60 mph.

Moderate tornado 73-112 mph The lower limit is the beginning of hurricane wind speed; peels surface off roofs; mobile homes pushed off foundations or overturned; moving autos pushed off the roads; attached garages may be destroyed.