What is a Hurricane?
by Kevin Caruso
A hurricane is a tropical cyclone that originates in an ocean or sea in the equatorial regions and involves heavy rains and a minimum wind speed of 74 mph (119 kh).
"Hurricane" is usually used to describe this type of storm over the Atlantic Ocean, whereas "typhoon" is usually used to describe the exact same type of storm in the Pacific Ocean.
Before a storm becomes a hurricane, it is a "tropical depression" and then a "tropical storm." Classification is determined by wind speed, and when wind speeds reach 74 mph, the storm is then classified as a hurricane.
Hurricanes have deepening low-pressure centers that take in moist air and thermal energy from the water's surface. Convection lifts the air, and as the air continues to rise, it eventually hits high pressure and is pushed outward. The resultant action can be viewed in the diagram below.