Hurricanes

Hurricane Formation

The Saffir-Simpson scale Category One Wind speed: 74-95 mph (119-153 km/h) Storm surge: 4-5 feet above normal Damage: Damage primarily to unanchored mobile homes, shrubbery, and trees along with some coastal road flooding and minor pier damage Examples: Allison, 1995; Danny, 1997 (pictured at left) Source: cnn.com (accessed on 8/29/05)

The Saffir-Simpson scale Category Two Wind speed: 96-110 mph (154-177 km/h) Storm surge: 6-8 feet above normal Damage: Roofing, door and window damage to buildings; Considerable damage to shrubbery and trees, mobile homes, poorly constructed signs, and piers Examples: Bonnie (satellite image at left), Georges, 1998 Source: cnn.com (accessed on 8/29/05)

The Saffir-Simpson scale Category Three Wind speed: 111-130 mph (178-209 km/h) Storm surge: 9-12 feet above normal Damage: Structural damage to small residences and utility buildings; foliage blown off trees and large trees blown down; mobile homes destroyed Examples: Roxanne, 1995; Fran, 1996 (pictured at left) Source: cnn.com (accessed on 8/29/05)

The Saffir-Simpson scale Category Four Wind speed: 131-155 mph (210-249 km/h) Storm surge: 13-18 feet above normal Damage: Extensive damage to doors, windows and lower floors of shoreline houses; total roof failures on small residences; shrubs, trees, and all signs blown down; mobile homes completely destroyed Examples: Hugo, 1989, (pictured at left); Luis, Felix, Opal, 1995 Source: cnn.com (accessed on 8/29/05)

The Saffir-Simpson scale Category Five Wind speed: Greater than 155 mph (249 km/h) Storm surge: generally greater than 18 feet above normal Damage: Complete roof failure on many buildings and some complete building failures with small utility buildings blown over or away; severe and extensive window and door damage; mobile homes completely destroyed Examples: Camille, 1969 (pictured at left); Gilbert, 1988; Andrew, 1992; Mitch, 1998 Source: cnn.com (accessed on 8/29/05)

Hurricane Formation

Hurricane Formation

Hurricane Hazards Storm Surge Storm surge is the greatest potential threat to life and property associated with hurricanes. A storm surge is a large dome of water, 50 to 100 miles wide, that sweeps across the coastline near where a hurricane makes landfall. It can be more than 15 feet deep at its peak. The level of surge in a particular area is primarily related to the intensity of the hurricane and slope of the continental shelf. The SLOSH model is used by communities to evaluate storm surge threat from different categories of hurricanes striking from various directions. Because storm surge has the greatest potential to kill more people than any of the other hurricane hazards, it is wise to err on the conservative side by planning for a storm that is one category more intense than is forecast. http://hurricanes.noaa.gov/prepare/summary_hazards.htm

Hurricane Hazards High Winds Typically, the more intense the storm (in terms of the Saffir-Simpson Hurricane Scale), the more wind damage a community will sustain, particularly if it does not have an effective mitigation program and has not prepared in advance for the storm. Tropical storm-force winds (39-73 mph) can also be dangerous, and it is wise to have evacuations completed before they reach your area. http://hurricanes.noaa.gov/prepare/summary_hazards.htm

Hurricane Hazards Heavy Rains Hurricanes (and some tropical storms) typically produce widespread rainfall of 6 to 12 inches or more, often resulting in severe flooding. Inland flooding has been the primary cause of tropical cyclone-related fatalities over the past 30 years. Rains are generally heaviest with slower moving storms (less than 10 mph). The heaviest rain usually occurs to the right of the cyclone track in the period 6 hours before and 6 hours after landfall. However, storms can last for days, depending on what inland weather features they interact with. Large amounts of rain can occur more than 100 miles inland where flash floods and mudslides are typically the major threats. http://hurricanes.noaa.gov/prepare/summary_hazards.htm

Hurricane Hazards Tornadoes Tornadoes are most likely to occur in the right-front quadrant of the hurricane. However, they are also often found elsewhere in the rainbands. Typically, the more intense a hurricane is, the greater the tornado threat. Tornado production can occur for days after landfall. Most tornadoes occur within 150 miles of the coast. Doppler radar systems can provide indications of tornados from a few minutes to about 30 minutes in advance. Consequently, preparedness is critical. http://hurricanes.noaa.gov/prepare/summary_hazards.htm

Before the Storm Hits Become informed: Learn about your community's emergency plans. Make sure you know the proper evacuation routes and locations of official emergency shelters. Source: http://abcnews.go.com/ (accessed on 8/30/05)

Before the Storm Hits Inspect your home and property for potential hazards: Secure or put away any loose material or objects that can be blown about by powerful winds. Know where and how to shut off your home's gas and power supplies in case you have to evacuate. Source: http://abcnews.go.com/ (accessed on 8/30/05)

Before the Storm Hits Cover exposed glass: Placing plywood boards and masking tape over windows and glass doors will reduce the risk of damage and injury to you and loved ones from flying glass fragments. Source: http://abcnews.go.com/ (accessed on 8/30/05)

Before the Storm Hits Secure important documents: Find and pack away vital papers — insurance policies, wills, licenses, stocks and property deeds. Be prepared to take them with you if you evacuate. Source: http://abcnews.go.com/ (accessed on 8/30/05)

Before the Storm Hits Consider special needs: Take into consideration if you, a member of your family or an immediate neighbor is elderly or needs special attention — regular access to a dialysis machine or other medical conditions, for example. Alert local authorities about these considerations so they can plan accordingly. Source: http://abcnews.go.com/ (accessed on 8/30/05)

What to do AFTER a Hurricane Be informed. Find out if local authorities have declared your neighborhood safe. Officials may close certain roads due to flooding or suspected road damage. Be aware if there are specific routes you need to take and if authorities have established assembly points for residents in your area. Source: http://abcnews.go.com/ (accessed on 8/30/05)

What to do AFTER a Hurricane Plan accordingly. Try to return to your home during daylight hours so you won't need to use lights. Make sure all family members are accounted for. Alert others of your status and plans to return home. Source: http://abcnews.go.com/ (accessed on 8/30/05)

What to do AFTER a Hurricane Drive carefully. Watch out for road hazards like debris and sinkholes. Do NOT drive through any water. Standing water may be hiding large sinkholes or may be deeper than it appears. Attempting to drive through — even in a sport utility truck — may stall your vehicle and put you in a more dangerous situation. Source: http://abcnews.go.com/ (accessed on 8/30/05)

What to do AFTER a Hurricane Be aware of fallen electrical power lines. Do not drive over them or through any water that may contain downed lines. If power lines fall on your vehicle while driving, continue to drive away from the danger. If your vehicle stalls, do not turn off the ignition and DO NOT get out. Wait for emergency rescue personnel and warn other bystanders away from your vehicle and potential danger. Source: http://abcnews.go.com/ (accessed on 8/30/05)

What to do AFTER a Hurricane Remain aware. Keep your radio tuned to local news and emergency broadcasts for updated information. If possible, keep a vehicle window slightly open so you can hear emergency sirens and other signals. Source: http://abcnews.go.com/ (accessed on 8/30/05)