The Saffir-Simpson Hurricane Scale is a scale classifying hurricanes by the intensity of their sustained winds, developed in 1969 by civil engineer Herbert Saffir and National Hurricane Center director Bob Simpson. Classifications are used to gauge the likely damage and flooding a hurricane will cause upon landfall. The Saffir-Simpson Hurricane Scale is used only to describe hurricanes forming in the Atlantic and northeast Pacific Oceans. Other areas use their own classification schemes.
The initial scale was developed by Saffir while on commission from the United Nations to study low-cost housing in hurricane-prone areas. While performing the study, Saffir realized there was no simple scale for describing the likely effects of a hurricane. Knowing the utility of the Richter magnitude scale in describing earthquakes, he devised a 1-5 scale based on wind speed that showed expected damage to structures. Saffir gave the scale to the NHC, and Simpson added in the effects of storm surge and flooding.
The five categories are, in order of increasing intensity:
| Category 1 | Sustained winds | 74-95 mi/h | 64-82 kt. | 119-153 km/h |
|---|---|---|---|---|
| Storm surge | 4-5 ft. | 1.2-1.5 m | ||
| Central pressure | 28.94 in. | 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 | Hurricane Agnes | |||
| Category 2 | Sustained winds | 96-110 mi/h | 83-95 kt. | 154-177 km/h |
| Storm surge | 6-8 ft. | 1.8-2.4 m | ||
| Central Pressure | 28.50-28.91 in. | 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 moorings may break their moorings. | |||
| Example storms | Hurricane Diane | |||
| Category 3 | Sustained winds | 111-130 mi/h | 96-113 kt. | 178-209 km/h |
| Storm surge | 9-12 ft. | 2.7-3.7 m | ||
| Central pressure | 27.91-28.47 in. | 945-964 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 | Hurricane Fran | |||
| Category 4 | Sustained winds | 131-155 mi/h | 114-135 kt. | 210-249 km/h |
| Storm surge | 13-18 ft. | 4.0-5.5 m | ||
| Central pressure | 27.17-27.88 in. | 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 | Galveston Hurricane of 1900 - Hurricane Hugo | |||
| Category 5 | Sustained winds | ≥156 mi/h | ≥136 kt. | ≥250 km/h |
| Storm surge | ≥18 ft. | ≥5.5 m | ||
| Central pressure | <27.17 in. | <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 | Hurricane Camille - Hurricane Gilbert - Hurricane Andrew | |||
All wind speeds are based on a one-minute average. Central pressure values are approximate. Intensity of example hurricanes is at time of landfall.
See also
- The Beaufort scale
- The Fujita scale