What is a Tropical Cyclone?
One of Nature’s Most Dangerous Disasters Defined
Tropical cyclones are some of the most devastating forces of nature, however many Americans are unfamiliar with the terminology used to describe them. Tropical cyclone is the broad term that covers a wide spectrum of rotating, organized storm systems that originate out at sea. They range from the weakest, tropical depressions, to the strongest, major hurricanes. Many people are familiar with tropical storms and hurricanes, which fall in the middle of the tropical cyclone categories.
A tropical cyclone with maximum sustained winds of 38 mph or less.
A tropical cyclone with maximum sustained winds of 39 to 73 mph.
A tropical cyclone with maximum sustained winds of 74 mph or higher.
A tropical cyclone with maximum sustained winds of 111 mph or higher.
Cyclones feature high winds and driving rains which can cause extensive damage to buildings, roads, and other infrastructure. However most injuries and deaths are caused by flooding and something called a storm surge that is associated with tropical cyclones. A storm surge occurs when whipping winds cause the sea level to rise and water to rush over coastal regions. The record for storm surge in the United States is 25 feet, set in 2005 by Hurricane Katrina.
Tropical Cyclones and the USA
About 30 tropical storms form each year in the oceans near the United States, with an average of 16 becoming full-fledged hurricanes. However, these storms are only truly dangerous for most Americans when they approach the coast. On average, the United States is struck with three hurricanes in a two year period, with just one classified as a major hurricane.
Minor Storms = Major Threat
However, even the less severe tropical depressions and tropical storms can be deadly if you are not prepared. Minor tropical cyclones can cause major flooding and other dangerous weather conditions, such as tornadoes. For example, in 2001 Tropical Storm Allison dumped over 40 inches of rain on the greater Houston area, causing 41 deaths and over $5 billion in damage.
Notorious Hurricanes in American History
Hurricane Katrina is the costliest hurricane to strike the US in recorded history, doing over $80 billion dollars in property damage in 2005. It also was responsible for loss of life to the heavily populated New Orleans metro area, as well as severe flooding for much of the gulf coast region.
Hurricane Andrew is the third most powerful storm to make landfall on US soil, with wind speeds of over 160 miles per hour. It caused extensive damage to south and central florida, as well as parts of Louisiana. In Miami-Dade County alone, Hurricane Andrew destroyed over 25,000 homes and damaged over 100,000 more.
The Great Galveston Hurricane of 1900 is the most deadly natural disaster in American history. The island community off the coast of Texas had little warning of the approaching storm. This tragic lack of preparedness, along with a high storm surge, caused somewhere between 6,000 and 12,000 deaths, with most estimates falling near 8,000.