We have provided a glossary of useful terms associated with hurricane activity.
Hurricane
An intense tropical weather disturbance with a well-defined circulation and sustained winds of 74 mph or higher.
Hurricane Eye
The relatively calm area near the center of a hurricane. Depending on the size and speed of the hurricane, it can take several minutes to several hours to pass. When it does, the calm ends suddenly and winds return, possibly with greater force, from the opposite direction.
Eye Wall
The circular wall of clouds around a storm's eye. This is where the storm's fastest winds are found.
Hurricane Watch
Issued when a hurricane may threaten an area within 36 hours.
Hurricane Warning
Issued when a hurricane is expected to strike within 24 hours.
Storm Surge
A dome of sea water that results from a storm's low atmospheric pressure but mainly from water pushed by strong winds. Its height depends on the strength of the storm and the nature of the ocean floor. Storm Surge can be higher in bays or rivers than on open beaches, can destroy entire buildings near the coast, and can kill more people than do high winds.
Tropical Wave
A defined area of showers and thunderstorms that maintains its identity for 24 hours or more. It is the first sign of a potential hurricane.
Tropical Depression
An organized system of thunderstorms with a defined circulation and sustained winds of less than 39 mph.
Tropical Storm
An organized system of strong thunderstorms with a defined circulation and sustained winds of 39 to 73 mph. Tropical Storms are given names and can quickly develop into hurricanes.
Tropical Storm Warnings
Notice that winds of 39 to 73 mph are expected.
Water Spout
A tornado occurring over water, appearing as a rapidly rotating, funnel-shaped column full of spray.
Gale Warnings
Winds 38 to 55 mph.
Category 1 Hurricane
Winds 74 to 95 mph. Low-lying coastal roads are inundated, small craft in exposed anchorages are torn from their moorings, and some pier damage can be expected.
Category 2 Hurricane
Winds 96 to 110 mph. Coastal roads and low-lying escape routes are cut off by rising water two to four hours before the hurricane eye arrives. Marinas are flooded. Some damage to windows, doors and roofing occur as well as major damage to mobile homes.
Category 3 Hurricane
Winds 111 to 130 mph. Low-lying escape routes are cut off by rising water three to four hours before the hurricane center arrives. Mobile homes are destroyed. Structural damage to small buildings occur. Serious coastal flooding.
Category 4 Hurricane
Winds 131 to 155 mph. Low-lying escape routes are cut off by rising water three to five hours before the hurricane center arrives. Major damage to lower floors of buildings near the shore occurs from flooding, battering by waves and debris. Collapse of some roofs on small residences.
Category 5 Hurricane
Winds in excess of 155 mph. Low-lying escape routes are cut off by rising water three to five hours before the hurricane center arrives. Small buildings are overturned. Extensive shattering of glass windows and the collapsing of roofs on many residential and industrial buildings occur. Some buildings will also collapse. |