How to prepare for a hurricane/tropical cyclone/typhoon.
Advice on Preparing for and Surviving Hurricanes
Hurricanes, also called tropical cyclones or typhoons (depending on where in the world they occur), are low pressure weather systems that most often form in the tropics. (The three terms for hurricanes have the same meaning, and are used interchangeably here.) Hurricanes are among the world's most destructive weather phenomena; that damage is usually due to storm surge, flooding, and/or high winds. Cyclones require tremendous energy to develop. The warm, moisture-laden air of the tropics contains this energy, thus most hurricanes develop within 20 degrees of the equator and begin to dissipate as they move into mid-latitudes. These tropical weather systems are classified as follows:
- Tropical Depression: An organized system of clouds and thunderstorms with a defined surface circulation and maximum sustained winds of 38 mph (61 kph) or less.
- Tropical Storm: An organized system of strong thunderstorms with a defined surface circulation and maximum sustained winds of 39-73 mph (63-118 kph).
- Hurricane/Tropical Cyclone/Typhoon: An intense tropical weather system of strong thunderstorms with a well-defined surface circulation and maximum sustained winds of 74 mph (118 kph) or higher.
Hurricanes are categorized according to the strength of their winds using the Saffir-Simpson Hurricane Scale:
|1||64-82 kts/74-95 mph/119-153 kph||Minimal: unsecured mobile homes, vegetation, and signs.|
|2||83-95 kts/96-110 mph/154-177 kph||Moderate: all mobile homes, roofs, small boats, flooding.|
|3||96-112 kts/111-129 mph/178-208 kph||Extensive: Small buildings, low-lying roads flooded.|
|4||113-136 kts/130-156 mph/209-251 kph||Extreme: roofs destroyed, felled trees, roads cut off, mobile homes destroyed. Beach homes flooded.|
|5||greater than 137 kts/156 mph/251 kph||Catastrophic: Buildings and vegetation destroyed. Major roads cut-off. Homes flooded.|
Preparing for a Hurricane
In most cases, meteorologists provide a fairly accurate forecast of where a storm will strike at least 36 hours in advance. Often, people in a storm's path will have three or more days to prepare.
Preparations to take in advance of a storm - Personal
- Learning the most likely hazards you will face if the storm strikes your area. Some locations are more vulnerable to storm surge (for example, low-lying areas near shallow bays) while others are more susceptible to wind damage or landslides (which can occur after significant rain). You could face the greatest threat from the building you are in, if it is poorly constructed.
- Determining where you could go if it becomes clear that the storm will impact your area. You may decide to stay where you are (for example, if you are in a sturdy building on relatively high ground), or move to another building in the local area. You may also decide that leaving the area will be the best strategy; in that case, learn the best evacuation routes and find out in advance how congested they become during evacuations, and plan accordingly.
- Once you know a storm strike is almost certain, buying enough bottled water to last a few days - whether you are staying or evacuating - and nonperishable food, such as energy bars, in case you become stranded. Also, ensure you have a flashlight with extra batteries.
- Contacting someone out of the area and inform them of your plans (whether you are staying or evacuating).
- Planning on the evacuation of pets as well. Most emergency shelters will not admit pets without proof of up-to-date vaccinations (such as a rabies tag).
- Even a Category 1 storm can knock out communications systems, including cellphone towers. Do not assume you will be able to make calls or have Internet access during a storm. Depending on wind speeds and other conditions, local authorities may shut off electrical power hours before the brunt of a storm hits an area. Ensure you have a radio with extra batteries, and be prepared to live without electrical power and communications for a few days.
Preparations to take in advance of a storm - Business
- Review and update emergency action plans well in advance of the storm. Consider conducting drills. Think about evacuating personnel to outside of the storm's area of impact. If there is any doubt as to the viability of a structure, evacuate ahead of time.
- Stock up on nonperishable supplies and bottled water for essential personnel who must remain during the storm. Procure additional first aid supplies, insect repellent, ice, vehicle fuel, spare batteries, flashlights, radios, mobile phones, etc. Consider purchasing a few non-powered hand tools (hammer, nails, crowbars, wood, etc.) to have on hand.
- Test emergency back-up power supplies and ensure there is plenty of fuel to operate a backup generator should power be knocked out for an extended period.
- Secure buildings, or make sure building owners do so well in advance of the storm's approach. Remove or secure any equipment that could become airborne during a storm.
- If possible, ensure that critical business operations can fail over to business units outside of the storm zone as needed.
During a Hurricane
If a cyclone watch is issued, the storm will affect the local area in 24 to 36 hours. Personnel should be prepared to do the following:
- Monitor local media for updated forecasts and evacuation notices.
- Review evacuation plans. Obey evacuation orders issued by authorities. Evacuations may be voluntary or mandatory, or may apply only to non-residents. Make sure you fully understand the order.
- If unable to evacuate or not ordered to do so, stay indoors and away from glass windows and doors. Keep curtains and blinds closed. Turn refrigerators to lowest setting, and shut off utilities if instructed to do so.
- During periods of high winds, take shelter well into the interior of your building lodging, and close all interior doors. Secure and brace all exterior doors. If possible, do not stay on the top floor of a building, which could become unsafe if the roof is damaged or destroyed.
What To Do After a Cyclone
Once the storm has passed, there are a number of residual threats that pose problems to businesses and personnel.
- Monitor local media for information related to medical treatment, potable water and food supply, and availability of shelter.
- Remain in your safe location until authorities state it is safe to leave, especially if you want to return to an area that had been evacuated.
- Heed the advice of authorities, especially government-imposed states of emergency or curfews.
- Limit driving. Streets will be strewn with debris - and possibly downed power lines - and authorities working on clean up, restoring power, and other safety issues will need priority on roads. Avoid flooded roads and waterways (see iJET's Advice Sheet on flooding).
- Do not drink or prepare food with tap water - unless you boil it first - until local officials have declared the water supply clean and safe.
- Avoid downed power lines. Report them or any other broken utility lines (gas, water, sewer) to local officials.
- Remain cautious in hilly areas, as the storm's rainfall may have increased the threat of landslides (see iJET's Advice Sheet on landslides).
- Related Advice:
What to do before, during and after a flood.
- Related Advice:
Information on how to identify and minimize the threat of landslides.