STATEWIDE - A hurricane is a type of tropical cyclone, the generic term for a low pressure system that generally forms in the tropics. A typical cyclone is accompanied by thunderstorms, and in the Northern Hemisphere, a counterclockwise circulation of winds near the earth's surface.
All Atlantic and Gulf of Mexico coastal areas are subject to hurricanes or tropical storms. Parts of the Southwest United States and the Pacific Coast experience heavy rains and floods each year from hurricanes spawned off Mexico. The Atlantic hurricane season lasts from June to November, with the peak season from mid-August to late October.
Hurricanes can cause catastrophic damage to coastlines and several hundred miles inland. Winds can exceed 155 miles per hour. Hurricanes and tropical storms can also spawn tornadoes and microbursts, create storm surges along the coast, and cause extensive damage from heavy rainfall.
Hurricanes are classified into five categories based on their wind speed, central pressure, and damage potential (see chart). Category Three and higher hurricanes are considered major hurricanes, though Categories One and Two are still extremely dangerous and warrant your full attention.
|Scale Number |
|Sustained Winds |
|Damage ||Storm Surge|
|1 ||74-95 ||Minimal: Unanchored mobile homes, |
vegetation and signs.
|2 ||96-110 ||Moderate: All mobile homes, roofs, |
small crafts, flooding.
|3 ||111-130 ||Extensive: Small buildings, low-lying |
roads cut off.
|4 ||131-155 ||Extreme: Roofs destroyed, trees |
down, roads cut off, mobile homes
destroyed. Beach homes flooded.
|5 ||More than 155 ||Catastrophic: Most buildings |
destroyed. Vegetation destroyed.
Major roads cut off. Homes flooded.
|Greater than 18 feet|
Hurricanes can produce widespread torrential rains. Floods are the deadly and destructive result. Slow moving storms and tropical storms moving into mountainous regions tend to produce especially heavy rain. Excessive rain can trigger landslides or mud slides, especially in mountainous regions. Flash flooding can occur due to intense rainfall. Flooding on rivers and streams may persist for several days or more after the storm.
Between 1970 and 1999, more people lost their lives from freshwater inland flooding associated with land falling tropical cyclones than from any other weather hazard related to tropical cyclones.
Source: Federal Emergency Management Agency (FEMA)