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Saffir-Simpson Hurricane Scalehttp://www.answers.com/topic/saffir-simpson-hurricane-scale Saffir-Simpson scale is the standard scale for rating the severity of hurricanes as a measure of the damage they cause; it is based on observations of numerous North Atlantic Basin hurricanes. First developed in the late 1960s by Herbert Saffir to quantity potential damage from hurricane winds, the scale was expanded in the early 1970s by Robert Simpson, then the Director of the National Hurricane Center. In its present form there are two definitive scales: the Saffir-Simpson Hurricane Scale and the Saffir-Simpson Hurricane Damage Intensity Scale. The Saffir-Simpson Hurricane Scale rates hurricanes from category 1 through category 5 in order of increasing intensity. Each intensity category specifies the range of conditions of four criteria: barometric (central) pressure, wind speed, storm surge, and damage potential. The Saffir-Simpson Hurricane Damage Intensity Scale, in addition to the wind speed, outlines the damage potentially possible with an associated categorized hurricane. As popularly employed, the Saffir-Simpson scale 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. A category 1, or "minimal," hurricane has winds of 74–95 mph (119–153 kph), has a storm surge of 3–5 ft (1.0–1.7 m), and will cause some damage to shrubbery, trees, and unanchored mobile homes and some flooding of low-lying coastal roads. A category 2, or "moderate," hurricane has winds of 96–110 mph (154–177 kph), has a storm surge of 6–8 ft (1.8–2.6 m), and will cause considerable damage to shrubbery with some trees being blown down, extensive damage to mobile homes, and inundation by rising water of coast roads and low-lying escape routes. A category 3, or "extensive," hurricane has winds of 111–130 mph (178–209 kph); has a storm surge of 9–12 ft (2.7–3.8 m); will cause large trees to be blown down, some structural damage to small buildings, destruction of mobile homes, and flooding of sea-level coastland 8 mi (13 km) or more inland; and requires evacuation of low-lying residences near the shoreline. A category 4, or "extreme," hurricane has winds of 131–155 mph (210–249 kph), has a storm surge of 13–18 ft (3.9–5.6 m), and will cause severe damage to roofing materials, windows, and doors, complete destruction of mobile homes, flooding of low-lying areas as much as 6 mi (10 km) inland, and major damage to structures near shore due to battering by waves and floating debris. A category 5, or "catastrophic," hurricane has winds greater than 155 mph (249 kph), has a storm surge higher than 18 ft (5.6 m), and will cause complete failure of roofs on residences and industrial buildings, the overturning or sweeping away of small buildings, and major damage to structures less than 15 ft (4.6 m) above sea level within 1,500 ft (457 m) of shore. A category 5 storm requires evacution of all residential areas on low-lying ground within 5–10 mi (8–16 km) of shore. A 1-5 rating based on the hurricane's present intensity. This scale 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. Category One Hurricane:Winds 74-95 mph (64-82 kt or 119-153 km/hr). Storm surge generally 4-5 ft above normal. No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery, and trees. Some damage to poorly constructed signs. Also, some coastal road flooding and minor pier damage. Hurricanes Allison of 1995 and Danny of 1997 were Category One hurricanes at peak intensity. Category Two Hurricane:Winds 96-110 mph (83-95 kt or 154-177 km/hr). Storm surge generally 6-8 feet above normal. Some roofing material, door, and window damage of buildings. Considerable damage to shrubbery and trees with some trees blown down. Considerable damage to mobile homes, poorly constructed signs, and piers. Coastal and low-lying escape routes flood 2-4 hours before arrival of the hurricane center. Small craft in unprotected anchorages break moorings. Hurricane Bonnie of 1998 was a Category Two hurricane when it hit the North Carolina coast, while Hurricane Georges of 1998 was a Category Two Hurricane when it hit the Florida Keys and the Mississippi Gulf Coast. Category Three Hurricane:Winds 111-130 mph (96-113 kt or 178-209 km/hr). Storm surge generally 9-12 ft above normal. Some structural damage to small residences and utility buildings with a minor amount of curtainwall failures. Damage to shrubbery and trees with foliage blown off trees and large trees blown down. Mobile homes and poorly constructed signs are destroyed. Low-lying escape routes are cut by rising water 3-5 hours before arrival of the center of the hurricane. Flooding near the coast destroys smaller structures with larger structures damaged by battering from floating debris. Terrain continuously lower than 5 ft above mean sea level may be flooded inland 8 miles (13 km) or more. Evacuation of low-lying residences with several blocks of the shoreline may be required. Hurricanes Roxanne of 1995 and Fran of 1996 were Category Three hurricanes at landfall on the Yucatan Peninsula of Mexico and in North Carolina, respectively. Category Four Hurricane:Winds 131-155 mph (114-135 kt or 210-249 km/hr). Storm surge generally 13-18 ft above normal. More extensive curtainwall failures with some complete roof structure failures on small residences. Shrubs, trees, and all signs are blown down. Complete destruction of mobile homes. Extensive damage to doors and windows. Low-lying escape routes may be cut by rising water 3-5 hours before arrival of the center of the hurricane. Major damage to lower floors of structures near the shore. Terrain lower than 10 ft above sea level may be flooded requiring massive evacuation of residential areas as far inland as 6 miles (10 km). Hurricane Luis of 1995 was a Category Four hurricane while moving over the Leeward Islands. Hurricanes Felix and Opal of 1995 also reached Category Four status at peak intensity. Category Five Hurricane:Winds greater than 155 mph (135 kt or 249 km/hr). Storm surge generally greater than 18 ft above normal. Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. All shrubs, trees, and signs blown down. Complete destruction of mobile homes. Severe and extensive window and door damage. Low-lying escape routes are cut by rising water 3-5 hours before arrival of the center of the hurricane. Major damage to lower floors of all structures located less than 15 ft above sea level and within 500 yards of the shoreline. Massive evacuation of residential areas on low ground within 5-10 miles (8-16 km) of the shoreline may be required. Hurricane Mitch of 1998 was a Category Five hurricane at peak intensity over the western Caribbean. Hurricane Gilbert of 1988 was a Category Five hurricane at peak intensity and is one of the strongest Atlantic tropical cyclones of record. For more information about Infrastructure Defense Technologies’ flood barriers and erosion control barriers and applications, please call us at 1-800-379-1822, email us at info@metalithH2O.com, info@infrastructure-defense.com or fill out our contact form.
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