About Hurricanes

When is Hurricane Season?

June 1st through November 30th

What is a Hurricane?

A hurricane is a tropical cyclone in the Northern Hemisphere, occurring in the North Atlantic Ocean, Caribbean Sea or Gulf of Mexico. It is an intense tropical weather system of strong thunderstorms with a well-defined surface circulation and sustained winds of at least 74 mph (64 knots) or greater. These winds blow in a large counterclockwise spiral around a relatively calm center of extremely low pressure called the eye.

Tropical cyclones occur in various parts of the world and are termed differently depending on where they originate.

• Hurricane: the North Atlantic Ocean
• Typhoon: the Northwest Pacific Ocean
• Cyclone: the Southwest Pacific Ocean or the Indian Ocean

Tropical storms are classified as follows:

• Tropical Wave: a large low-pressure system in the tropics and subtropics.
• Tropical Disturbance: a group of thunderstorms that moves together through the tropics for a t least 24 hours, but with no noticeable circular motion.
• Tropical Depression: an organized system of thunderstorms and massed clouds with a defined surface circulation and maximum sustained winds of 38 mph (33 knots).
• Tropical Storm: an organized system of strong thunderstorms with a well-defined surface circulation and maximum sustained winds of 39-73 mph (34-63 knots).
• Hurricane: an organized system of strong thunderstorms with a well-defined surface circulation and minimum sustained winds of 74 mph (64 knots).

The different tropical storm and hurricane warnings:

• Tropical Storm Watch: an advisory issued by the National Hurricane Center when tropical storm conditions, with winds of 39 to 73 mph, could threaten a coastal area within 24 to 36 hours.
• Tropical Storm Warning: an advisory issued when winds of 39 to 73 mph are expected.
• Hurricane Watch: Hurricane conditions are possible in the specified area of the watch within 36 hours.
• Hurricane Warning: Hurricane conditions are expected in the specified area of the warning within 24 hours.

Hurricanes Categories:

Hurricanes are further classified into 5 categories according to the strength of their sustained winds. The United States uses the Saffir-Simpson Intensity Scale to estimate a hurricane’s potential for flooding and damage to property based on the storm’s strength.

Based on their intensity, the estimated damage from hurricanes is predicted based on their category:

Category 1: Minimal - 74-95 mph
Damage primarily to shrubbery and trees, and unanchored mobile homes. No real damage to building structures. Some coastal flooding, minor pier damage, and some exposed small crafts torn from moorings.

Category 2: Moderate - 96-110 mph
Considerable damage to shrubbery and trees, with some trees blown down. Major damage to some mobile homes. Some roofing material, door, and window damage. No major damage to buildings. Flooding of coast and low-lying inland roads 2 to 4 hours before arrival of hurricane center. Evacuation of some shoreline residences and low-lying areas required. Flooding and damage to piers and marinas. Exposed small crafts torn from moorings.

Category 3: Extensive - 111-130 mph
Large trees blown down. Mobile homes destroyed. Some damage to roofs, with some wind and door damage to buildings. Major flooding near the coast destroys smaller structures with larger structures damaged by floating debris. Flooding of low-lying inland roads by rising water 3 to 5 hours before hurricane center arrives. Terrain may be flooded well inland. Evacuation of low-lying residences within several blocks of shoreline required.

Category 4: Extreme - 131-155 mph
Shrubs and trees blown down. Extensive damage to roofs, windows and doors. Complete roof structure failure on many small buildings. Complete destruction of mobile homes. Terrain will be flooded well inland. Major beach erosion. Evacuation of areas within 2 miles of shore.

Category 5: Catastrophic - 156+ mph
Shrubs and trees blown down. Complete destruction of mobile homes. Severe damage to roofs, windows and doors. Complete roof failure on many buildings. Some complete building failures with some small buildings blown away. Flooding causes major damage to lower floors of all structures near the shoreline. Massive evacuation of residential areas required.