Storm Center - Hurricane Terms

Tropical Disturbance - An area of organized clouds generally 100 to 300 miles in diameter, orginating in the tropics or subtropics and maintaining its identity for 24 hours or more.

Tropical Depression - A tropical cyclone in which the maximum sustained surface wind is 38 mph (33 knots) or less.

Tropical Storm - A tropical cyclone in which the maximum sustained surface wind is 39 mph (34 knots) or more.

Sustained Wind - The mean wind speed in miles per hour or knots occuring during any one-minute span.

Storm Surge - An abnormal rise in sea level produced by a hurricane. Storm surges can be from 4 feet above normal to as high as 20 feet or more. Waves still continue above the storm surge. This combination of high water and strong seas can be deadly. The storm surge accounts for the most deaths during a hurricane.

Hurricane Watch - An announcement for an area that a hurricane or hurricane conditions may pose a threat to coastal areas, generally within 36 hours.

Hurricane Warning - A warning that sustained winds of 74 mph (64 knots) or higher associated with a hurricane are expected within 24 hours of less.

The Saffir/Simpson Hurricane Scale
Category One - Winds: 74-95 mph
No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery and trees. Also, some coastal flooding and minor pier damage.

Category Two - Winds: 96-110 mph
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.

Category Three - Winds: 111-130 mph
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 damaged by floating debris. Terrain may be flooded well inland.

Category Four - Winds: 131-155 mph
More extensive curtainwall failures with some complete roof structure failure on small residences. Major erosion of beach areas. Terrain may be flooded well inland.

Category Five - Winds: 155+ mph
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.