What Are Hurricanes?
Hurricanes are a type of tropical cyclone — a large, rotating, low-pressure system that brings rain and wind — with sustained wind speeds of over 74 miles per hour. Hurricanes can spawn other weather problems, such as tornadoes and water spouts, flash floods, and dangerous thunderstorms.
Hurricane season in the Atlantic Ocean, which sees the most hurricane activity, is from June to November.
How are hurricanes categorized?
Hurricanes are categorized based on the maximum speed of sustained winds within the cyclone. The Saffir-Simpson scale ranges from 1 for low-level hurricanes to 5 for the most unforgiving and catastrophic.
|Category||Sustained Wind Speeds||Expected Damage|
|1||74–95 mph||Minimal: Damage to plants, signs, and unanchored mobile homes.|
|2||96–110 mph||Moderate: Damage to roofs, serious damage to mobile homes, low-level flooding|
|3||111–130 mph||Extensive: Damage to small buildings, low roads cut off, flooding|
|4||131–155 mph||Extreme: Roofs destroyed, mobile homes destroyed, trees down, major flooding|
|5||156 mph or more||Catastrophic: Most buildings and plants destroyed, major flooding|
How are hurricanes named?
Beginning in 1953, the (U.S.) National Hurricane Center maintained a list that it used to name tropical cyclones, including hurricanes. That list is now maintained by the World Meteorological Organization (WMO), which keeps separate lists for cyclones in the Atlantic, in the eastern north Pacific, and in the eastern central Pacific. Other organizations are responsible for naming cyclones in other parts of the world.
The lists for the Atlantic and eastern northern Pacific each actually comprise six different lists of 21 names that are used in rotation, which means that the names used for this year's hurricanes will pop up again in six years. If more than 21 cyclones occur in the year, subsequent storms are named after the letters of the Greek alphabet.
When a hurricane is particularly devastating or costly, its name is removed from the list and replaced with a new one. There will, for instance, be no more hurricanes named Hugo (1989), Andrew (1992), Katrina (2005), or Irene (2011).
Until 1979, tropical storms and hurricanes were given only women's names. Since then, they have been given alternating male and female names.