Hurricanes and Tornadoes are measured on scales. Tornadoes are measured on the Enhanced Fujita Scale (from EF0 to EF5) based on how much damage they produce. Hurricanes are measured by the highest sustained winds.
The Saffir-Simpson Hurricane Scale is a 1-5 rating based on the hurricane's present intensity. This is used to give an estimate of the potential property damage and flooding expected along the coast from a hurricane landfall. Wind speed is the determining factor in the scale, as storm surge values are highly dependent on the slope of the continental shelf in the landfall region. Note that all winds are using the U.S. 1-minute average.
Tropical
Depression
| Susatined Winds | 0-38 MPH | 0-62 KPH | Tropical
Depression
#10 (2005) | | Storm Surge | 0-3 ft | 0-.9 m | | Central Pressure | | | Potential Damage | Very little wind damage. Usually, minor Flooding. However, depending on the path and strength of the storm, major flooding can occur. | | Example Storms | TD 10 (2005) |
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Tropical
Storm
| Susatined Winds | 39-73 MPH | 63-117 KPH | Tropical Storm
Alberto (2006) | | Storm Surge | 0-3 ft | 0-.9 m | | Central Pressure | | | Potential Damage | Some light wind damage. Usually, minor Flooding. However, depending on the path and strength of the storm, major flooding can occur. | | Example Storms | Alberto (2006), Allison (2001) |
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Category 1
Hurricane
| Susatined Winds | 74-95 MPH | 119-153 KPH |
Category 1
Hurricane Ophelia (2005)
| | Storm Surge | 4-5 ft | 1.2-1.5 m | | Central Pressure | > 980 mb | | Potential Damage | No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery, and trees. Also, some coastal flooding and minor pier damage. | | Example Storms | Ernesto (2006), Ophelia (2005), Gaston (2004) |
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Category 2
Hurricane | Susatined Winds | 96-110 MPH | 154-177 KPH |
Category 2
Hurricane Erin (1995)
| | Storm Surge | 6-8 ft. | 1.8-2.4 m | | Central Pressure | 965-979 mb | | Potential Damage | Some roofing material, door, and window damage. Considerable damage to vegetation, mobile homes, etc. Flooding damages piers and small craft in unprotected anchorages may break their moorings | | Example Storms | Juan (2003), Erin (1995), Floyd (1998) at landfall |
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Category 3
Major
Hurricane | Susatined Winds | 111-130 MPH | 179-209 KPH |
Category 3
Major Hurricane
Fran (1997) | | Storm Surge | 9-12 ft. | 2.7-3.7 m | | Central Pressure | 945-965 mb | | Potential Damage | Some structural damage to small residences and utility buildings, with a minor amount of curtainwall failures. Mobile homes are destroyed. Flooding near the coast destroys smaller structures with larger structures damaged by floating debris. Terrain may be flooded well inland. | | Example Storms | Fran (1997), Katrina (2005) at landfall in Louisiana |
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Category 4
Major
Hurricane | Susatined Winds | 131-155 MPH | 210-249 KPH |
Category 4
Major Hurricane Hugo (1989) | | Storm Surge | 13-18 ft. | 4.0-5.5 m | | Central Pressure | 920-944 mb | | Potential Damage | More extensive curtainwall failures with some complete roof structure failure on small residences. Major erosion of beach areas. Terrain may be flooded well inland. | | Example Storms | Hazel (1954), Charley (2004), Hugo (1989) at landfall in Charleston, SC |
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Category 5
Major
Hurricane
| Susatined Winds | 156+ MPH | 250+ KPH |
Category 5
Major Hurricane
Isabel (2003)
| | Storm Surge | 19 ft.+ | 5.5 m + | | Central Pressure | < 920 mb | | Potential Damage | Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. Flooding causes major damage to lower floors of all structures near the shoreline. Massive evacuation of residential areas may be required. | | Example Storms | Camille (1968), Andrew (1992), Isabel (2003), Katrina (2005), Rita (2005), Wilma (2005) |
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Category 6
| Susatined Winds | Unknown | Unknown |
There is no category 6
| | Storm Surge | Unknown | Unknown | | Central Pressure | Unknown | | Potential Damage | Inconceivable. While there have been proposals to add a "Category 6" with winds over 175-180 MPH, none have been successful. | | Example Storms | None. Sample candidates for category 6 storms would include Wilma (2005), Allen (1980), Camille (1968) |
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Other places in the world use scales that may have different measurements and terms. You may hear of "Cyclones" and "Super Typhoons". In the Atlantic (and Eastern Pacific), these would be called "Hurricanes". You can learn more about the scales and terms used around the world on the web
