Common tropical weather terms - CBS46 News

Common tropical weather terms

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Hurricane season is almost here. Familiarize your self with the most common-used tropical weather terms below.

When is hurricane season?

Hurricane season is from June 1 through November 30 in the Atlantic basin. This is the time period when tropical systems typically develop in the Atlantic, but it's not impossible to get tropical systems any time of year, which we were reminded of in January when a rare tropical system developed nearly five months ahead of schedule.

What is the Atlantic basin?

The Atlantic basin (sometimes referred to as simply the Atlantic) refers to the Atlantic Ocean, Caribbean and Gulf of Mexico. Tropical cyclones that impact the U.S. develop in these waters.

Tropical disturbance

You'll hear about tropical disturbances a lot! These are just organized thunderstorms that frequently develop in the tropics during hurricane season. We see a ton of disturbances each season that never actually develop into a system, but if it does...

Tropical cyclone

Once those showers and thunderstorms in the waters develop a closed center of's officially a tropical cyclone. Once a disturbance becomes a tropical cyclone, we'll call it a tropical depression, tropical storm or hurricane depending on how strong the winds are.

Tropical depression

A tropical cyclone with winds less than 39 mph is called a tropical depression. Once a tropical depression forms, advisories and forecasts are issued by the National Hurricane Center.

Tropical storm

A tropical depression becomes a tropical storm when winds reach 39 mph. Once a depression becomes a storm, it's given an official name. When a tropical disturbance becomes a tropical cyclone, it's usually classified as either a tropical depression (if winds are under 39 mph), but sometimes can go straight to tropical storm if winds are already at 39 mph.


A tropical cyclone becomes a hurricane once winds reach 74 mph. Hurricanes keep the same name as tropical storms and are categorized based on their wind speed.

  • Category 1 - Minimal damage with 74-95 mph winds.
  • Category 2 - Moderate damage with 96-110 mph winds.
  • Category 3 - Extensive damage with 111-129 mph winds.
  • Category 4 - Extreme damage with 130-156 mph winds.
  • Category 5 - Catastrophic damage with winds greater than 157 mph.

Major hurricane

A hurricane is considered major when it becomes a category 3 hurricane or stronger. 

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