3+-+Hurricane

=__ What is a hurricane? __=

Hurricanes are giant, spiraling tropical storms that can pack wind speeds of over 160 miles (257 kilometers) an hour and unleash more than 2.4 trillion gallons (9 trillion liters) of rain a day.

These same tropical storms are known as cyclones in the northern Indian Ocean and Bay of Bengal, and as typhoons in the western Pacific Ocean.

The Atlantic Ocean’s hurricane season peaks from mid-August to late October and averages five to six hurricanes per year.

[[image:http://celebrating200years.noaa.gov/historymakers/Smagorinsky/hurricane_emily650.jpg width="324" height="283"]]
Hurricanes begin as tropical disturbances in warm ocean waters with surface temperatures of at least 80 degrees Fahrenheit (26.5 degrees Celsius).

These low pressure systems are fed by energy from the warm seas. If a storm achieves wind speeds of 38 miles (61 kilometers) an hour, it becomes known as a tropical depression.

A tropical depression becomes a tropical storm, and is given a name, when its sustained wind speeds top 39 miles (63 kilometers) an hour.

When a storm’s sustained wind speeds reach 74 miles (119 kilometers) an hour it becomes a hurricane and earns a category rating of 1 to 5 on the Saffir-Simpson scale.


 * Category 1 || Minimal || wind speeds of 74-95 MPH ||
 * Category 2 || Moderate || wind speeds of 96-110 MPH ||
 * Category 3 || Extensive || wind speeds of 111-130 MPH ||
 * Category 4 || Extreme || wind speeds of 131-155 MPH ||
 * Category 5 || Catastrophic || wind speeds of over 155 MPH ||

Hurricanes are enormous heat engines that generate energy on a staggering scale. They draw heat from warm, moist ocean air and release it through condensation of water vapor in thunderstorms.

Hurricanes spin around a low-pressure center known as the “eye.” Sinking air makes this 20- to 30-mile-wide (32- to 48-kilometer-wide) area notoriously calm. But the eye is surrounded by a circular “eye wall” that hosts the storm’s strongest winds and rain. __ SIMPLE ANIMATED HURRICANE FORMATION __

__ Effect of Hurricanes __
These storms bring destruction ashore in many different ways. When a hurricane makes landfall it often produces a devastating storm surge that can reach 20 feet (6 meters) high and extend nearly 100 miles (161 kilometers). Ninety percent of all hurricane deaths result from storm surges.

A hurricane’s high winds are also destructive.. Torrential rains cause further damage by spawning floods and landslides, which may occur many miles inland. The best defense against a hurricane is an accurate forecast that gives people time to get out of its way. The National Hurricane Center issues hurricane watches for storms that may endanger communities, and hurricane warnings for storms that will make landfall within 24 hours.


 * **Hurricane Resources** ||
 * [[image:http://i.infoplease.com/images/tv/arrw_yel_theme.gif width="8" height="15"]] || [|Tracking a Hurricane] ||
 * [[image:http://i.infoplease.com/images/tv/arrw_yel_theme.gif width="8" height="15"]] || [|New Orleans, La.] ||
 * [[image:http://i.infoplease.com/images/tv/arrw_yel_theme.gif width="8" height="15"]] || [|Family Disaster Plan] ||
 * [[image:http://i.infoplease.com/images/tv/arrw_yel_theme.gif width="8" height="15"]] || [|How to Prepare for a Hurricane] ||
 * [[image:http://i.infoplease.com/images/tv/arrw_yel_theme.gif width="8" height="15"]] || [|Retired Hurricane Names] ||
 * [[image:http://i.infoplease.com/images/tv/arrw_yel_theme.gif width="8" height="15"]] || [|Activity: Storm Warning Flags] ||
 * [[image:http://i.infoplease.com/images/tv/arrw_yel_theme.gif width="8" height="15"]] || [|Beaufort Wind Scale] ||
 * [[image:http://i.infoplease.com/images/tv/arrw_yel_theme.gif width="8" height="15"]] || **More** [|Hurricane Resources] ||

Further links:
 * [|National Geographic]
 * [|How stuff works]