A hurricane is a type of tropical cyclone or severe tropical storm that forms in the southern Atlantic Ocean, Caribbean Sea, Gulf of Mexico, and in the eastern Pacific Ocean. 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. Parts of the Southwest United States and the Pacific Coast also 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. The Eastern Pacific hurricane season begins May 15 and ends November 30.
Hurricanes can cause catastrophic damage to coastlines and several hundred miles inland. Hurricane can produce winds exceeding 155 miles per hour as well as tornadoes and mircrobursts. Additionally, hurricanes can create storm surges along the coast and cause extensive damage from heavy rainfall. Floods and flying debris from the excessive winds are often the deadly and destructive results of these weather events. Slow moving hurricanes traveling into mountainous regions tend to produce especially heavy rain. Excessive rain can trigger landslides or mud slides. Flash flooding can occur due to intense rainfall.
Before a Hurricane
To prepare for a hurricane, you should take the following measures:
Learn the elevation level of your property and whether the land is flood-prone. This will help you know how your property will be affected when storm surge or tidal flooding are forecasted.
Identify levees and dams in your area and determine whether they pose a hazard to you.
Learn community hurricane evacuation routes and how to find higher ground. Determine where you would go and how you would get there if you needed to evacuate.
Make plans to secure your property:
Cover all of your home’s windows. Permanent storm shutters offer the best protection for windows. A second option is to board up windows with 5/8” marine plywood, cut to fit and ready to install. Tape does not prevent windows from breaking.
Install straps or additional clips to securely fasten your roof to the frame structure. This will reduce roof damage.
Be sure trees and shrubs around your home are well trimmed so they are more wind resistant.
Clear loose and clogged rain gutters and downspouts.
Reinforce your garage doors; if wind enters a garage it can cause dangerous and expensive structural damage.
Plan to bring in all outdoor furniture, decorations, garbage cans and anything else that is not tied down.
Determine how and where to secure your boat.
Install a generator for emergencies.
If in a high-rise building, be prepared to take shelter on or below the 10th floor.
Consider building a safe room.
Hurricanes cause heavy rains that can cause extensive flood damage in coastal and inland areas. Everyone is at risk and should consider flood insurance protection. Flood insurance is the only way to financially protect your property or business from flood damage. To learn more about your flooding risk and how to protect yourself and your business, visit the Federal Insurance and Mitigation Administration (NFIP) Web site,www.floodsmart.gov or call 1-800-427-2419.
The Saffir-Simpson Hurricane Wind Scale classifies hurricanes into five categories based on their sustained wind speed at the indicated time. The Saffir-Simpson Hurricane Wind Scale provides information on wind impacts only. The scale does not address the potential for other hurricane-related impacts, such as storm surge, rainfall-induced floods, and tornadoes.
Hurricanes reaching Category 3 and higher are considered major hurricanes because of their potential for significant loss of life and property. Category 1 and 2 storms are still dangerous, however, and require preventive measures.
Saffir-Simpson Hurricane Wind Scale Summary
Scale Number (Category)
Sustained Winds (MPH)
Very dangerous winds will produce some damage
Minor damage to exterior of homes
Toppled tree branches, uprooting of smaller trees
Extensive damage to power lines, power outages
Extremely dangerous winds will cause extensive damage
Major damage to exterior of homes
Uprooting of small trees and many roads blocked
Guaranteed power outages for long periods of time – days to weeks
Devastating damage will occur
Extensive damage to exterior of homes
Many trees uprooted and many roads blocked
Extremely limited availability of water and electricity
Catastrophic damage will occur
Loss of roof structure and/or some exterior walls
Most trees uprooted and most power lines down
Isolated residential due to debris pile up
Power outages lasting for weeks to months
157 or higher
Catastrophic damage will occur
A high percentage of homes will be destroyed
Fallen trees and power lines isolate residential areas
Power outages lasting for weeks to months
Most areas will be uninhabitable
The greatest potential for loss of life related to a hurricane is from the storm surge!
Storm surge is simply water that is pushed toward the shore by the force of the winds swirling around the storm. This advancing surge combines with the normal tides to create the hurricane storm tide, which can increase the mean water level to heights impacting roads, homes and other critical infrastructure. In addition, wind driven waves are superimposed on the storm tide. This rise in water level can cause severe flooding in coastal areas, particularly when the storm tide coincides with the normal high tides. Because much of the United States' densely populated Atlantic and Gulf Coast coastlines lie less than 10 feet above mean sea level, the danger from storm tides is tremendous.
The storm surge combined with wave action can cause extensive damage, severely erode beaches and coastal highways. With major storms like Katrina, Camille and Hugo, complete devastation of coastal communities occurred. Many buildings withstand hurricane force winds until their foundations, undermined by erosion, are weakened and fail.
Know the Terms
Familiarize yourself with these terms to help identify a hurricane hazard:
Tropical Cyclone: A warm-core non-frontal synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and a closed surface wind circulation about a well-defined center. Once formed, a tropical cyclone is maintained by the extraction of heat energy from the ocean at high temperature and heat export at the low temperatures of the upper troposphere.
Tropical Depression: A tropical cyclone in which the maximum sustained surface wind speed (using the U.S. 1-minute average) is 38 mph (33 knot) or less.
Tropical Storm: A tropical cyclone in which the maximum sustained surface wind speed (using the U.S. 1-minute average) ranges from 39 mph (34 knots) to 73 mph (63 knots).
Hurricane: A tropical cyclone in which the maximum sustained surface wind (using the U.S. 1-minute average) is 74 mph (64 knots) or more.
Storm Surge: An abnormal rise in sea level accompanying a hurricane or other intense storm, and whose height is the difference between the observed level of the sea surface and the level that would have occurred in the absence of the cyclone. Storm surge is usually estimated by subtracting the normal or astronomic high tide from the observed storm tide. Storm surge can reach heights well over 20 feet and can span hundreds of miles of coastline.
Storm Tide: The actual level of sea water resulting from the astronomic tide combined with the storm surge.
Hurricane Warning: An announcement that hurricane conditions (sustained winds of 74 mph or higher) are expected somewhere within the specified area. Because hurricane preparedness activities become difficult once winds reach tropical storm force, the hurricane warning is issued 36 hours in advance of the anticipated onset of tropical-storm-force winds.
Hurricane Watch: An announcement that hurricane conditions (sustained winds of 74 mph or higher) are possible within the specified area. Because hurricane preparedness activities become difficult once winds reach tropical storm force, the hurricane watch is issued 48 hours in advance of the anticipated onset of tropical-storm-force winds.
Tropical Storm Warning: An announcement that tropical storm conditions (sustained winds of 39 to 73 mph) are expected somewhere within the specified area within 36 hours.
Tropical Storm Watch: An announcement that tropical storm conditions (sustained winds of 39 to 73 mph) are possible within the specified area within 48 hours.
Short Term Watches and Warnings: These watches/warnings provide detailed information about specific hurricane threats, such as flash floods and tornadoes.
During a Hurricane
If a hurricane is likely in your area, you should:
Listen to the radio or TV for information.
Secure your home, close storm shutters and secure outdoor objects or bring them indoors.
Turn off utilities if instructed to do so. Otherwise, turn the refrigerator thermostat to its coldest setting and keep its doors closed.
Turn off propane tanks.
Avoid using the phone, except for serious emergencies.
Moor your boat if time permits.
Ensure a supply of waterfor sanitary purpose such as cleaning and flushing toilets. Fill the bathtub and other larger containers with water.
Drive only if necessary and avoid flooded roads and washed-out bridges. Stay off the streets. If you must go out watch for fallen objects; downed electrical wires; and weakened walls, bridges, roads, and sidewalks.
Keep away from loose or dangling power lines and report them immediately to the power company.
Walk carefully around the outside your home and check for loose power lines, gas leaks and structural damage before entering.
Stay out of any building if you smell gas, floodwaters remain around the building or your home was damaged by fire and the authorities have not declared it safe.
Inspect your home for damage. Take pictures of damage, both of the building and its contents, for insurance purposes. If you have any doubts about safety, have your residence inspected by a qualified building inspector or structural engineer before entering.
Use battery-powered flashlights in the dark. Do NOT use candles. Note: The flashlight should be turned on outside before entering - the battery may produce a spark that could ignite leaking gas, if present.
Watch your pets closely and keep them under your direct control. Watch out for wild animals, especially poisonous snakes. Use a stick to poke through debris.
Avoid drinking or preparing food with tap water until you are sure it’s not contaminated.
Check refrigerated food for spoilage. If in doubt, throw it out.
Wear protective clothing and be cautious when cleaning up to avoid injury.
Use the telephone only for emergency calls.
NEVER use a generator inside homes, garages, crawlspaces, sheds, or similar areas, even when using fans or opening doors and windows for ventilation. Deadly levels of carbon monoxide can quickly build up in these areas and can linger for hours, even after the generator has shut off.
Your friends, neighbors and colleagues are more likely to prepare for the various weather hazards that frequently impact the nation when they see those around them prepare, so inspire them to act by being an example yourself. The first step you can take is to Pledge to Prepare. The resources you will receive once doing so provide tools for making your family and community, safer, more resilient, and better prepared.