• Tropical Cyclone Threats
• Storm Surge
  • What is Storm Surge?
  • Influences
  • SLOSH
  • Using SDP
  • Surge Mapping
  • Local Forecasts
• Heavy Rains & Inland Flooding
  • Influences
  • Web Products
  • River Forecast Centers
  • National Forecasts
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• High Winds
  • Wind Strength
  • Effects
  • After Landfall
  • Local Forecasts
• Tornadoes
  • Characteristics
  • Damage Scale
  • Local Forecasts
• Questions

Wind Strength

Once winds exceed 73 mph (63 kt), a storm’s intensity is expressed using the Saffir-Simpson Hurricane Wind Scale, which categorizes storms by wind speed and potential damage. Note that a Category 1 hurricane has lower speed winds compared to storms in higher categories. A Category 4 hurricane would usually (but not always) be expected to cause 100 times the damage of a Category 1 storm. A "major" hurricane is classified as Category 3 or greater. As indicated in the Basics section, the strongest winds usually occur on the right side of the eyewall of the hurricane.

Category	Definition–Effects	Examples
1	Winds: 74-95 mph (119-153 km/hr ) Very dangerous winds will produce some damage. Some damage to building structures could occur, primarily to unanchored mobile homes (mainly pre-1994 construction). Some damage is likely to poorly constructed signs. Loose outdoor items will become projectiles, causing additional damage. Persons struck by windborne debris risk injury and possible death. Numerous large branches of healthy trees will snap. Some trees will be uprooted, especially where the ground is saturated. Many areas will experience power outages with some downed power poles.	Hurricane Dolly (2008) brought Category 1 winds and impacts to South Padre Island, Texas.
2	Winds: 96-110 mph ( 154-177 km/hr) Extremely dangerous winds will cause extensive damage. Some roofing material, door, and window damage of buildings will occur. Considerable damage to mobile homes (mainly pre-1994 construction) and poorly constructed signs is likely. A number of glass windows in high rise buildings will be dislodged and become airborne. Loose outdoor items will become projectiles, causing additional damage. Persons struck by windborne debris risk injury and possible death. Numerous large branches will break. Many trees will be uprooted or snapped. Extensive damage to power lines and poles will likely result in widespread power outages that could last a few to several days.	Hurricane Frances (2004) brought Category 2 winds and impacts to coastal portions of Port St. Lucie, Florida with Category 1 conditions experienced elsewhere in the city.
3	Winds: 111-130 mph (178-209 km/hr) Dangerous winds will cause extensive damage. Some structural damage to houses and buildings will occur with a minor amount of wall failures. Mobile homes (mainly pre-1994 construction) and poorly constructed signs are destroyed. Many windows in high rise buildings will be dislodged and become airborne. Persons struck by windborne debris risk injury and possible death. Many trees will be snapped or uprooted and block numerous roads. Near total power loss is expected with outages that could last from several days to weeks.	Hurricane Ivan (2004) brought Category 3 winds and impacts to coastal portions of Gulf Shores, Alabama with Category 2 conditions experienced elsewhere in this city.
4	Winds: 131-155 mph ( 178-209 km/hr) Devastating damage will occur. Some wall failures with some complete roof structure failures on houses will occur. All signs are blown down. Complete destruction of mobile homes (primarily pre-1994 construction). Extensive damage to doors and windows is likely. Numerous windows in high rise buildings will be dislodged and become airborne. Windborne debris will cause extensive damage and persons struck by the wind-blown debris will be injured or killed. Most trees will be snapped or uprooted. Fallen trees could cut off residential areas for days to weeks. Electricity will be unavailable for weeks after the hurricane passes.	Hurricane Charley (2004) brought Category 4 winds and impacts to coastal portions of Punta Gorda,Florida with Category 3 conditions experienced elsewhere in the city.
5	Winds: 155+ mph ( 249+ km/hr ) Catastrophic damage will occur. Complete roof failure on many residences and industrial buildings will occur. Some complete building failures with small buildings blown over or away are likely. All signs blown down. Complete destruction of mobile homes (built in any year). Severe and extensive window and door damage will occur. Nearly all windows in high rise buildings will be dislodged and become airborne. Severe injury or death is likely for persons struck by wind-blown debris. Nearly all trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months.	Hurricane Andrew (1992)brought Category 5 winds and impacts to coastal portions of Cutler Ridge, Florida with Category 4 conditions experienced elsewhere in south Miami-Dade County.