Rating Hurricanes:The Saffir-Simpson Scale
Three Category 4 hurricanes have made a U.S. landfall in a little less than a month,causing billions of dollars in damage and likely leading to the retirement of the names Harvey,Irma and Maria from use in future hurricane seasons.
(FULL COVERAGE:Hurricane Central)
Hurricane Maria's landfall with winds of 155 mph Wednesday in Puerto Rico was the latest powerful storm in this historic and disastrous stretch for the continental U.S. and its Puerto Rico and Virgin Islands territories.
In the weeks before Maria,hurricanes Harvey and Irma made landfall at Category 4 intensity with 130 mph winds on Aug. 25 in Rockport,Texas,and Sept. 10 in the Florida Keys,respectively.
Winds for a Category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale range from 130 mph to 156 mph. Winds of that strength are capable of causing catastrophic damage. The scale does not factor other major hazards from hurricanes such as storm surge and flooding rainfall.
The landfall of Harvey and Irma at Category 4 strength was already a historic event,marking the first time two Atlantic hurricanes struck the U.S. at that intensity in the same year. With Puerto Rico taking a direct hit from Maria,the U.S. has now endured landfalls from three Category 4 hurricanes.
Category 4 or stronger Atlantic hurricane landfalls in the Lower 48 are a rare occurrence,with only 27 documented since 1851,including Harvey and Irma. Three of those 27 landfalls were Category 5 hurricanes.
Puerto Rico has experienced four Category 4 or stronger landfalls,including Maria,which was the strongest landfall there since 1928.
As mentioned earlier,the names Harvey,Irma and Maria could be retired from being used in future hurricane seasons.
(MORE:Retired Atlantic Tropical Storm and Hurricane Names)
Atlantic hurricane and tropical storm name lists repeat every six years unless one is so destructive and/or deadly that the World Meteorological Organization votes to retire that name from future lists.
The last time three Atlantic tropical storm or hurricane names were retired in a single season was 2008,when Gustav,Ike and Paloma were eliminated from future use.
Only 10 other years since 1954 have had three or more Atlantic tropical storm or hurricane names retired,according to the National Hurricane Center. 2017 could be the 11th year to have that many retirees after the WMO meets next year to make their decision on what names will be removed from use.
