Cuồng phong là một loại lốc xoáy nhiệt đới hay bão nhiệt đới mạnh hình thành ở phía nam Đại Tây Dương, Biển Caribbe, Vịnh Mê-xi-cô và phía đông Thái Bình Dương. Lốc xoáy thông thường kéo theo bão có sấm sét, và là luồng gió ngược chiều kim đồng hồ gần bề mặt trái đất ở Bán Cầu Bắc.
Tất cả các khu vực bờ biển của Đại Tây Dương và Vịnh Mê-xi-cô đều phải chịu ảnh hưởng của những cơn cuồng phong. Các khu vực ở Tây Nam Hoa Kỳ và Bờ Biển Thái Bình Dương cũng gặp những trận mưa lớn và lũ lụt mỗi năm do cuồng phong ở Mê-xi-cô sinh ra. Mùa cuồng phong ở Đại Tây Dương kéo dài từ tháng 6 đến tháng 11, mùa cao điểm là từ giữa tháng 8 đến cuối tháng 10. Mùa cuồng phong ở Phía Đông Thái Bình Dương bắt đầu vào ngày 15 tháng 5 và kết thúc vào ngày 30 tháng 11.
Cuồng phong có thể gây ra thiệt hại nghiêm trọng tới vùng bờ biển và vài trăm dặm vùng đất liền. Cuồng phong có thể sinh ra gió vượt quá 155 dặm mỗi giờ cũng như lốc xoáy và dòng giáng. Ngoài ra, cuồng phong có thể khiến nước biển dâng do bão dọc bờ biển và gây thiệt hại trên diện rộng từ những trận mưa lớn. Lũ lụt và các mảnh vụn bay do gió quá mạnh thường là hậu quả chết người và tàn phá của các sự cố thời tiết này. Cuồng phong di chuyển chậm tiến vào vùng núi có xu hướng tạo ra các trận mưa đặc biệt lớn. Mưa quá nhiều có thể gây lở đất hoặc lở bùn. Lũ quét có thể xảy ra do lượng mưa dữ dội.
Từ năm 1970 đến 1999, có nhiều người thiệt mạng do ngập lụt vùng nước ngọt trong đất liền liên quan tới lốc xoáy nhiệt đới hơn bất kỳ mối nguy hiểm do thời tiết nào khác liên quan đến các cơn bão đó.
Before a Hurricane
To prepare for a hurricane, you should take the following measures:
- To begin preparing, you should build an emergency kit and make a family communications plan.
- Know your surroundings.
- 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” exterior grade or marine plywood, cut to fit and ready to install. Another year-round option would be installation of laminated glass with impact-resistant glazing. 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, when high winds are present, be prepared to take shelter on a lower floor because wind conditions increase with height, and in a small interior room without windows. When flooding may be occuring, be prepared to take shelter on a floor safely above the flooding and wave effects.
- 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.
Saffir-Simpson Hurricane Wind Scale
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
Extremely dangerous winds will cause extensive damage
Devastating damage will occur
Catastrophic damage will occur
157 or higher
Catastrophic damage will occur
For more information on the Saffir-Simpson Hurricane Wind Scale, visit the National Hurricane Center.
For information on the Scale as it affects Hawaii, visit the National Hurricane Center here.
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 water for sanitary purpose such as cleaning and flushing toilets. Fill the bathtub and other larger containers with water.
- Find out how to keep food safe during and after and emergency.
You should evacuate under the following conditions:
If you are directed by local authorities to do so. Be sure to follow their instructions.
- If you live in a mobile home or temporary structure – such shelter are particularly hazardous during hurricane no matter how well fastened to the ground.
- If you live in a high-rise building – hurricane winds are stronger at higher elevations.
- If you live on the coast, on a floodplain, near a river, or on an island waterway.
Read more about evacuating yourself and your family. If you are unable to evacuate, go to your wind-safe room. If you do not have one, follow these guidelines:
- Stay indoors during the hurricane and away from windows and glass doors.
- Close all interior doors – secure and brace external doors.
- Keep curtains and blinds closed. Do not be fooled if there is a lull; it could be the eye of the storm – winds will pick up again.
- Take refuge in a small interior room, closet or hallway on the lowest level.
- Lie on the floor under a table or another sturdy object.
- Avoid elevators.
After a Hurricane
- Continue listening to a NOAA Weather Radio or the local news for the latest updates.
- Stay alert for extended rainfall and subsequent flooding even after the hurricane or tropical storm has ended.
- If you have become separated from your family, use your family communications plan or contact the American Red Cross at 1-800-RED-CROSS/1-800-733-2767 or visit the American Red Cross Safe and Well site: www.safeandwell.org
- The American Red Cross also maintains a database to help you find family. Contact the local American Red Cross chapter where you are staying for information. Do not contact the chapter in the disaster area.
- If you evacuated, return home only when officials say it is safe.
- If you cannot return home and have immediate housing needs. Text SHELTER + your ZIP code to 43362 (4FEMA) to find the nearest shelter in your area (example: shelter 12345).
- For those who have longer-term housing needs, FEMA offers several types of assistance, including services and grants to help people repair their homes and find replacement housing. Apply for assistance or search for information about housing rental resources
- 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.
Es más probable que sus amigos, vecinos y colegas se preparen para enfrentar diversos peligros meteorológicos que suelen azotar a la nación cuando ven que las personas que los rodean se preparan; por lo tanto, inspírelos predicando con el ejemplo. La primera medida que puede tomar es Comprometerse a prepararse (en inglés) . Una vez que lo haga, los recursos que recibirá brindarán herramientas para que su familia y su comunidad estén más seguros, tengan una mayor capacidad de recuperación y estén mejor preparados.
Además, el widget le permite compartir nuestro contenido directamente con las personas que visitan su sitio web. Los enlaces redireccionan a los usuarios a un contenido que los ayudará a saber más sobre sus riesgos y a cómo tomar medidas, y donde podrán ver qué hacen las demás personas para estar preparadas. Usted o su equipo web solo tienen que copiar nuestro breve código, agregarlo a su sitio y listo.
The Emergency Management Institute (EMI) is part of the Department of Homeland Security’s (DHS) Federal Emergency Management Agency (FEMA). EMI offers a free Independent Study Program (ISP) to train the nation’s emergency management network and to help educate the general public in disaster preparedness.
Suggested emergency management courses to prepare for the hurricane season:
- IS-324.A Community Hurricane Preparedness
- IS-366 Planning for the Needs of Children in Disasters
- IS-271.A Anticipating Hazardous Weather and Community Risk for Emergency Managers
- IS-22 Are You Ready? An In-Depth Guide to Citizen Preparedness
- IS-10.A Animals in Disaster: Module A. Awareness and Preparedness
- IS-11.A Animals in Disaster: Module B. Community Planning
- IS-288 The Role of Voluntary Agencies in Emergency Management
- IS-244.B Developing and Managing Volunteers
- IS-111.A Livestock in Disasters
- IS-909 Community Preparedness: Implementing Simple Activities for Everyone
- IS-247.A Integrated Public Alert and Warning System (IPAWS) for Public Safety Officials
- IS-546.A Continuity of Operations Awareness
- IS-318 Mitigation Planning for Local and Tribal Communities