Hurricane Season Terms & Acronyms

Familiarize yourself with the terms that are used to identify a hurricane.

A hurricane watch or tropical storm watch means a hurricane or a tropical storm threat to the area is possible within the next 48 hours. Be prepared to evacuate, as even a tropical storm can gain strength quickly and many homes, including mobile homes, reside in high risk areas. Monitor local radio and television news outlets or listen to NOAA Weather Radio for the latest developments.
A hurricane warning or tropical storm warning is issued when a hurricane or tropical storm is expected in the area within the next 36 hours. If local authorities advise you to evacuate, you need to leave immediately.
Hurricanes are classified according to the Saffir-Simpson Wind Scale into five categories based on their wind speed, central pressure, and damage potential. Category Three and higher storms are considered major hurricanes. While less intense, Category One and Two hurricanes and tropical storms are still extremely dangerous and warrant your full attention.
Storm Surge is an abnormal rise in sea level accompanying a hurricane or other intense storm. As a hurricane makes landfall, this storm surge is pushed onshore, causing severe flooding and destruction. The waves of the surge can undermine waterfront structures, wash out roadbeds, destroy ships, and cause drowning. Storm Surge forecasts are included in hurricane and tropical storm advisories and statements issued by the National Weather Service, but arbitrary levels are no longer assigned to each category. Storm Surge is instead now calculated for each storm, taking into account variables such as tide, storm size and rain amounts, and should be much more accurate and reliable.

Saffir-Simpson Wind Scale
Category	Sustained Wind Speeds (MPH)	Pressure (MB)	Typical Damage
Tropical Depression	<39	--
Tropical Storm	39-73	--
Category One Hurricane	74-95	>980	Minimal - Damage is done primarily to shrubbery and trees, unanchored manufactured homes are damaged, some signs are damaged, no real damage is done to structures on permanent foundations.
Category Two Hurricane	96-110	956-980	Moderate - SOme trees are toppled, some roof coverings are damaged, major damage is done to manufactured homes.
Category Three Hurricane	111-130	945-965	Extensive Damage - Large trees are toppled, some structural damage is done to roofs, manufactured homes are destroyed, structural damage is dones to samll homes and utility buildings.
Category Four Hurricane	131-155	920-945	Extreme Damage - Extensive damage is done to roofs, windows, and doors; roof systems on small buildings completely fail, some curtain walls fail.
Category Five Hurricane	>155	<920	Catastrophic Damage - Roof damage is considerable and widespread, window and door damage is severe, there are extensive glass failures, some buildings fail completely.

A tropical storm has all the characteristics of a hurricane, including storm surge, with winds of 39 to 73 mph.
Hurricanes frequently produce widespread torrential rains with floods. Deadly and destructive flooding and flash flooding can result from these rains. Slow moving storms tend to produce especially heavy rain. Flooding in creeks, drainage channels, rivers and streams may persist for several days or more after the storm.
Hurricanes frequently produce widespread torrential rains with floods. Deadly and destructive flooding and flash flooding can result from these rains. Slow moving storms tend to produce especially heavy rain. Flooding in creeks, drainage channels, rivers and streams may persist for several days or more after the storm.
Emergency Management: Organized analysis, planning, decision making, and assignment of available resources to mitigate, prepare for, respond to, and recover from the effects of all hazards.
Emergency Operations Center (EOC): A pre-designated facility established by an agency or jurisdiction to coordinate the overall agency or jurisdictional response and support to an agency.
The Governor of South Carolina may authorize a voluntary evacuation or require a mandatory evacuation. You are encouraged to evacuate when instructed. Evacuations of specific areas occur when authorities determine that there is an immediate threat to your life and safety. Please review the Citizen's Guide to Emergency Preparedness for emergency supplies and other information that you should have on hand for evacuation. PREPARE NOW. Know where you will go if evacuated. Anticipate that roads on and off the Island will be congested and difficult to maneuver. Leave early if possible.
Federal Emergency Management Agency (FEMA): The Federal agency created in 1979 to provide a single point of accountability for Federal activities related to disaster mitigation and emergency preparedness, response, and recovery.
Flash Flood: A flood that crests in a short period of time and is often characterized by high velocity flow. It is often the result of heavy rainfall in a localized area.
Flash Flood Wathc: A flash flood is possible in the area; stay alert.
Flash Flood Warning: A flash flood is imminent; take immediate action.
Gale Force Winds: Winds with a speed from 32 to 63 mph.
Hazard Mitigation: Actions taken to prevent disasters or to reduce the damage caused by hazards that cannot be avoided.
High Wind Warning: Sustained winds of 40 mph or greater, or winds gusting to 58 mph or greater which are either expected or observed regardless of duration. Will be issued for inland areas, away from the coast, where hurricane force conditions are not expected.
Huricane Season: Begins June 1st and ends November 30th. Most active time in the Atlantic Ocean is in August and September.
Re-entry and Recovery: After the disaster has occurred, the Town will issue an all clear bulletin to all participating agencies and announce times when reentry into evacuated areas may begin.
Small Craft Cautionary Statements: When a tropical cyclone threatens a coastal area, small craft operators are advised to remain in port or not to venture into open sea.

Acronyms

DHEC	Department of Health and Environmental Control
EOC	Emergency Operations Center
FEMA	Federal Emergency Management Agency
GIS	Geographic Information System
NFIP	National Flood Insurance Program
NHC	National Hurricane Center
NOAA	National Oceanic Atmospheric Administration