Hurricanes: Understand the Dangers

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Hurricanes not only pack high winds, but can also cause torrential rains that lead to flash flooding and abnormally high waves and storm surge. Each of these alone can pose a serious threat to life and property. Taken together they are capable of inflicting a large loss of life and widespread destruction. Hurricanes have been called “The Greatest Storms on Earth“. This title is well earned, as these massive storms can be 600 miles across, pack winds from 74 mph to over 150 mph, and effect millions in their path. Hurricanes bring with them many threats. There are four primary hazards associated with a hurricane. They are storm surge, winds, tornadoes, and heavy rain.

Historically, storm surge has been one of the most significant hazards associated with hurricanes. Storm surge is a large volume of ocean water that is driven ashore by a land falling hurricane or tropical storm. Storm surge is a rapid rise in sea level, accompanied by large battering waves. The surge is caused by strong onshore winds forcing the ocean level to rise up and flow inland. Storm surge effects coastal areas as well as canals, rivers, and other low lying areas near tidal bodies of water. Storm surge can destroy buildings, cut new inlets through barrier islands, and completely change the coastline.

The winds associated with hurricanes and strong tropical storms are another significant hazard associated with dangerous storms. Each hurricane and tropical storm is different. No matter what the strength of the hurricane, the winds are dangerous and precautions should be taken seriously. The strongest winds associated with a hurricane are usually found around the core surrounding the calm center of the eye. However, strong damaging winds associated with squalls can also be found in the outer fringes of the storm. Winds can turn outside objects, such as lawn chairs, into missiles of destruction and cause significant damage. Winds associated with a hurricane can be felt hundreds of miles from the center and well inland.

Tornadoes associated with hurricanes are caused by the numerous squalls and thunderstorms that make up the hurricane or tropical storm. Tornadoes in hurricanes and tropical storms can be hard to detect and develop with little warning and may be wrapped in rain making them almost impossible to see. They are more frequent in the outer fringes of the storm but can develop anywhere. Tornadoes can cause significant damage to buildings, power poles, and turn outside objects into deadly missiles.

Rainfall associated with hurricanes and tropical storms can cause significant flooding and damage. Recently more people have died as a result of inland flooding than any other hazard associated with hurricanes or tropical storms. Rainfall amounts over 15 inches can be expected during hurricanes and tropical storms. Flooding is the leading cause of damage to homes in the United States. Flooding associated with hurricanes and tropical storms can be felt for hundreds of miles inland.

Know Your Hurricane Categories

Tropical Storm

Wind Speed: 40-73 mph

Expected Sea Surge: 2-3 ft

Damage: Minimal – Damage Primarily to shrubs, trees and foliage. Some damage to street signs. Some flooding of low-lying coastal roads, pier damage, beaches swamped.

Hurricane Category 1

Wind Speed: 74-96 mph

Expected Sea Surge: 4-5 ft

Damage: Minimal – Damage Primarily to shrubs, trees and foliage. Some damage to street signs. Some flooding of low-lying coastal roads, pier damage, beaches swamped, some small craft in exposed anchorages torn from moorings.

Hurricane Category 2

Wind Speed: 96-110 mph

Expected Sea Surge: 6-8 ft

Damage: Moderate – Considerable damage to foliage; some trees blown down. Some damage to building roofs, windows and doors. No major damage to inland buildings. Considerable damage to inland buildings. Considerable damage to piers, marinas, beaches and small craft in unprotected anchorage.

 Hurricane Category 3

Wind Speed:  111-130 mph

Expected Sea Surge: 9-12 ft

Damage: Extensive – Large trees blown down. Damage to roofs, windows and doors and some structural damage to small buildings. Serious flooding along coasts, with larger structures battered and smaller structures destroyed by waves, floating debris and floodwaters.

Hurricane Category 4

Wind Speed: 131-155 mph

Expected Sea Surge: 13-18 ft

Damage: Extreme – Shrubs, trees and all signs blown down. Extensive damage to roofs windows and doors. Complete failure of roofs on many small residences. Major flood damage to lower floors of structures near coast due to flooding, beach erosion, waves and floating debris.

Hurricane Category 5

Wind Speed: Over 155 mph

Exected Sea Surge: 18+ ft

Damage: Catastrophic – Shrubs, large trees and all signs blown down, with great damage to windows and doors. Some buildings completely destroyed. Major damage to lower floors of all structures less than 15 feet above sea level or within 50 yards of shore.

What to do at the start of the hurricane season

Be informed

Learn all you can about hurricanes, how they can effect Cayman and how to prepare. Learn about your area. Knowing how high above sea level it is, and its flooding history will give you an idea of how safe your area is. But remember: new buildings, roads and other construction could make flooding more likely even if it was not a problem in the past. You can find out the elevation of your area from the Lands and Survey Department at 949-7900. In-land areas which have had serious flooding in past storms include the West Bay Peninsula, Red Bay, Prospect, Savannah, central George Town, areas around the North Sound, low lying areas of Cayman Brac, and Little Cayman. Learn the location of official public shelters and emergency medical centres – note the closest ones to you.

Make a plan

Make sure the house you choose is well constructed and on high ground or has a foundation high enough to avoid too much water getting in.

Decide where you will store your boat in an emergency and how to secure it.

Make sure home and property insurance is up-to-date. And that you understand what your coverage provides.