What is a Hurricane?

Learn About Hurricanes

• What is a Hurricane?
  
  
• Our personal experience with Hurricanes
  
• How are the Hurricane Categories Determined?
  
  
• How are Hurricanes Named?
  
  
• Hurricane Terms
  
  
• What to do before a Hurricane

What is a Hurricane?

A hurricane is a type of tropical cyclone, the generic term for a low pressure system that generally forms in the tropics. A typical cyclone is accompanied by thunderstorms, and in the Northern Hemisphere, a counterclockwise circulation of winds near the earths surface.

All Atlantic and Gulf of Mexico coastal areas are subject to hurricanes or tropical storms. Parts of the Southwest United States and the Pacific Coast experience heavy rains and floods each year from hurricanes spawned off Mexico. The Atlantic hurricane season lasts from June to November, with the peak season from mid-August to late October.

Hurricanes can cause catastrophic damage to coastlines and several hundred miles inland. Winds can exceed 155 miles per hour. Hurricanes and tropical storms can also spawn tornadoes and microbursts, create storm surges along the coast, and cause extensive damage from heavy rainfall.

Our personal experience with Hurricanes

When we lived in Chapel Hill, North Carolina in 1996, Hurricane Fran was heading in our direction. Waiting for Fran to arrive was a very traumatic experience. When the hurricane hit, it seemed to go on and on forever. Every gust of wind could bring down a tree, break a window or blow off the roof.

When it was over, we found out that a tornado touched down on the street behind us. It took down three blocks of trees and power lines. We were without electricity and water for three weeks. After seeing all the hurricane damages that happened around us, we felt very fortunate that we had survived it.



How are the Hurricane Categories Determined?

Hurricanes are classified into five categories based on their wind speed, central pressure, and damage potential. Category Three and higher hurricanes are considered major hurricanes, though Categories One and Two are still extremely dangerous and warrant your full attention.

Hurricanes can produce widespread torrential rains. Floods are the deadly and destructive result. Slow moving storms and tropical storms moving into mountainous regions tend to produce especially heavy rain. Excessive rain can trigger landslides or mud slides, especially in mountainous regions. Flash flooding can occur due to intense rainfall. Flooding on rivers and streams may persist for several days or more after the storm.

Between 1970 and 1999, more people lost their lives from freshwater inland flooding associated with land falling tropical cyclones than from any other weather hazard related to tropical cyclones.

How are Hurricanes Named?

Since 1953, Atlantic tropical storms have been named from lists originated by the National Hurricane Center and now maintained and updated by an international committee of the World Meteorological Organization. The lists featured only women’s names until 1979. After that, men’s and women’s names were alternated. Six lists are used in rotation. Thus, the 2001 lists will be used again in 2007.

The only time there is a change in the list is if a storm is so deadly or costly that the continued use of the name would be inappropriate for reasons of sensitivity. When this occurs, the name is stricken from the list and another name is selected to replace it.

Sometimes names are changed. Lorenzo replaced Luis and Michelle replaced Marilyn.

Hurricane: Know the Terms

Familiarize yourself with these terms to help identify a hurricane hazard:

Tropical Depression
An organized system of clouds and thunderstorms with a defined surface circulation and maximum sustained winds of 38 MPH (33 knots) or less. Sustained winds are defined as one-minute average wind measured at about 33 ft (10 meters) above the surface.

Tropical Storm
An organized system of strong thunderstorms with a defined surface circulation and maximum sustained winds of 39–73 MPH (34–63 knots).

Hurricane
An intense tropical weather system of strong thunderstorms with a well-defined surface circulation and maximum sustained winds of 74 MPH (64 knots) or higher.

Storm Surge
A dome of water pushed onshore by hurricane and tropical storm winds. Storm surges can reach 25 feet high and be 50–1000 miles wide.

Storm Tide
A combination of storm surge and the normal tide (i.e., a 15-foot storm surge combined with a 2-foot normal high tide over the mean sea level created a 17-foot storm tide).

Hurricane/Tropical Storm Watch
Hurricane/tropical storm conditions are possible in the specified area, usually within 36 hours. Tune in to NOAA Weather Radio, commercial radio, or television for information.

Hurricane/Tropical Storm Warning
Hurricane/tropical storm conditions are expected in the specified area, usually within 24 hours.

Short Term Watches and Warnings
These warnings provide detailed information about specific hurricane threats, such as flash floods and tornadoes.

"What is a Hurricane How To" guides and hurricane facts for protecting your property from hurricane damages, flooding & high winds.

The following information will give you guidelines on what to do before a Hurricane

To prepare for a hurricane, you should take the following hurricane safety measures:

• Make plans to secure your property. Permanent storm shutters offer the best protection for windows. A second option is to board up windows with 5/8” marine plywood, cut to fit and ready to install. 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.
  
  
• Clear loose and clogged rain gutters and downspouts.
  
  
• Determine how and where to secure your boat.
  
  
• Consider building a safe room.

Information on What is a Hurricane is provided by FEMA

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