In order to help explain certain natural disasters scientists have come up with systems to measure the severity of natural disasters like storms, earthquakes and tornadoes. Most of these measures have been developed and revised over the last 100 years. Several of these are described below.
A tornado is a defined as a destructive vortex of rotating winds with the appearance of a funnel-shaped cloud moving beneath a large powerful storm system.
The EF Scale was adopted by the United States in 2007. The EF scale replaced the F (Fujita) Scale, which was developed by Dr. Theodore Fujita. The main purpose of the EF scale is to describe the amount of damage that was or could be done by a tornado. The real difference between the two scales is the estimated speed of the wind eminating from a tornado. The original Fujita scale was developed in the 1970s at the University of Chicago. The newer EF scale merely represents the ‘Enhanced’ Fujita scale.
Each of these scales are numbered from 0 to 5, one preceded by the letter F (fujita scale) and the other measured by the letter E, for example the weakest tornado would be an F0 or E0, depending on the scale used. The table below will help describe the wind speed ranges for each of these scales.
Fujita and Enhanced Fujita Scales
|Fujita||Wind Speed||Damage Potential||Enhanced Fujita||Wind Speed|
|F0||40-72 mph||light damage||EF0||65-85 mph|
|F1||73-112 mph||moderate damage||EF1||86-110 mph|
|F2||113-157 mph||considerable damage||EF2||111-135 mph|
|F3||158-207 mph||severe damage||EF3||136-165 mph|
|F4||208-260 mph||devastating damage||EF4||166-200 mph|
|F5||261-318 mph||incredible damage||EF5||over 200 mph|
While these measures were only recently developed in the 1970s, there’s no accurate measure of storms before this time, however as these scales were developed prior storms and their scales were estimated. Since 1950, there have been 59 officially rated F5/EF5 tornados in the United States as well as 1 in Canada. The most powerful storms ever, would obviously be EF or F5 storms.
Historic F5 storms:
|1764||Woldegk, Germany||1 death|
|1845||Montville, Seine-Maritime, France||75 deaths|
|1899||St. Croix County, Wisconsin||117 deaths|
|1896||Sherman, Texas||73 deaths|
|1893||Pomeroy, Iowa||71 deaths|
First Half of 20th Century (1900-1949)
|1947||Glazier/Higgins, Texas||181 deaths|
|1936||Tupelo, Mississippi||216 deaths|
|1913||Omaha, Nebraska||113 deaths|
|1905||Snyder, Oklahoma||97 deaths|
Please note, the storms in the 2 tables above are estimates based on the historic records and projections.
Second Half of 20th Century (1950-1999)
|1953||Waco, Texas||114 deaths|
|1953||Flint, Michigan||116 deaths|
|1953||Worchester, Massachusetts||94 deaths|
|1955||Udall, Kansas||80 deaths|
|1984||Ivanovo, Soviet Union||92 deaths|
21st Century Tornados
|2011||Joplin, Missouri||158 deaths|
|2011||Hackleburg, Alabama||72 deaths|
|2011||Tuscaloosa-Birmingham, Alabama||64 deaths|
|2011||Rainsville, Alabama||25 deaths|
|2013||Moore, Oklahoma||24 deaths|