What terms should I know about?

Saffir/Simpson Scale:  Hurricanes are assigned five categories, Category 1 being a minimum hurricane and a Category 5 being the most sever or intense.  Remember, hurricanes, no matter how weak, are dangerous. The combination of storm surge, wind, and other contributing factors determine a hurricane's destructive power. Therefore, all categories should be taken seriously and with caution.

Category 1
74-95 mph
Damage to buildings is slight. Manufactured homes that are unanchored along with shrubbery and trees sustain some damage. Some minor pier damage along with coastal road flooding.
Category 2
96-110 mph
Some damage to buildings, such as roofing materials, doors and windows. Considerable amount of damage to vegetation, unanchored manufactured homes and piers. Two to 4 hours before arrival of center, coastal and low-lying escape routes flood. Small craft in unprotected anchorages break moorings.
Category 3
111-130 mph
Unanchored manufactured homes may be destroyed. Structural and some curtain wall damage occurs to small residences and utility buildings. Flooding destroys smaller structures near coast. Larger structures are damaged by floating debris. Terrain that is continuously lower than 5 feet above sea level may be flooded 8 miles inland.
Category 4
131-155 mph
Extensive curtain wall failures with some complete roof structure failures on small residences may occur. Major erosion to beaches and damage to lower floors of structures near the shore occurs. Terrain continuously lower than 10 feet above sea level may be flooded, requiring massive evacuation of residential areas as far as 6 miles inland.
Category 5
155+ mph
Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. Major damage to lower floors of all structures located less than 15 miles above sea level and within 500 yards of shoreline. Massive evacuation of residential areas on low ground within 5 to 10 miles of shoreline may be required.

Emergency Alert System: A state of the art digital system designed to give emergency information and instructions from federal, state, and local authorities.  When activated, it broadcasts the latest information on weather reports, road conditions, evacuations, shelter locations, and re-entry information.

Emergency Shelter: Shelter provided during and immediately following a disaster.

Evacuation Order: The MOST important instruction you will receive from local government officials.  In a slow moving Category 3 and all Category 4 and 5 hurricanes, the State of Louisiana Evacuation Plan goes into effect.

Small Craft Advisory: When a tropical cyclone threatens a coastal area, small craft operators are advised to remain in port.

Eye: Low pressure center of a hurricane surrounded by the most intense area of the storm, and in contrast to the eye wall, winds are normally calm and sometimes the sky clears inside the eye.

Eye Wall: The ring of thunderstorms that surrounds the storm's eye.  The heaviest rain, strongest winds, and worst turbulence are normally in this area.

Flash Flood Watch: National Weather Service issues  this type of watch when local flooding can be expected within 12 to 24 hours.

Flood Warning: National Weather Service issues a flood warning when flood waters are expected to exceed flood stage at any point on rivers and bayous.  Most flood warnings will be issued 24 to 60 hours in advance of the crest.

Gale Warning: Issued when winds of 39-54 mph (34-47 knots) are expected.

Hurricane Warning: Hurricane conditions are possible in the specified are of the watch, usually within 12 to 24 hours. Don't wait for this warning to begin storm preparations. Plan and prepare ahead of time!

Landfall: the term used that indicates the moment the eye of the hurricane hits land.

Millibar: A metric measure of air pressure.

Storm Surge: A great dome of water, often 50 miles wide, that comes sweeping across the coastline near the area where the eye of a hurricane makes landfall.

Storm Warning: Issued when winds of 55-73 mph are expected. If a hurricane is expected to strike a coastal area, gale or storm warnings will not usually precede hurricane warnings.

Tornado Warning: Indicates a tornado has been spotted. Be prepared to take shelter.

Tornado Watch: Conditions are favorable for this type of storm.

Tropical Cyclone: General term for all cyclonic circulations originating over tropical water.

Tropical Depression: Rotary circulation at the surface with a highest constant wind speed of 38 mph.

Tropical Disturbance: A moving area of thunderstorms in the tropics that maintains its identity for 24 hours or more.

Tropical Storm: Distinct rotary circulation with a constant wind speed ranges of 39-73 mph.

Tropical Wave: A kink or bend in the normally straight flow of the surface air in the tropics that form a low pressure trough, or pressure boundary, with showers and thunderstorms. These may eventually develop into a tropical cyclone.

Typhoon: A hurricane in the North Pacific Ocean, west of the International Date Line.



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