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Hurricane Information
Storm Definitions

Tropical Disturbance
A tropical wave or easterly wave defined as a cluster of clouds and thunderstorms moving through the tropics.

Tropical Depression
When the tropical wave develops a rotary, cyclonic circulation with sustained winds to 38 mph.

Tropical Storm
Once winds within a tropical system reach 39 miles per hour and the distinct low pressure area is well defined by a rotating circulation, the system is considered a tropical storm and is given a name.

Hurricane
A hurricane has sustained winds exceeding 74 miles per hour or greater, dangerously high water and rough seas. Hurricanes are categorized by severity using the Saffir/Simpson Scale:

Saffir/Simpson Hurricane Scale

Category One
Winds 74-95 MPH
Or storm surge 4-5 feet above normal.*

Category Two
Winds 96-110 MPH
Or storm surge 6 feet above normal.*

Category Three
Winds 111-129 MPH
Or storm surge 9-12 feet above normal.*

Category Four
Winds 130-156 MPH
Or storm surge 13-18 feet above normal.*

Category Five
Winds 157 MPH and greater
Or storm surge greater than 18 feet above normal.*

*Actual storm surge values will vary considerably depending on coastal configurations and other factors.

Watches and Warnings
When a tropical storm or hurricane threatens, the National Hurricane Center will issue advisories based on the projected time until landfall of the storm.

Watch
A tropical storm or hurricane watch means that tropical storm or hurricane conditions pose a possible threat in a specified region within 36 hours. You should begin preliminary preparations. Stay tuned to local news or the weather channel for updates.

Warning
A tropical storm or hurricane warning means that tropical storm or hurricane conditions are expected in a specified region within 24 hours. All preparations should be completed. Stay tuned to local news or the weather channel for evacuation orders and additional instructions.

Hurricane Information

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