What’s the difference between a hurricane watch and warning, and how are hurricanes classified?

Here’s what distinguishes a hurricane watch from a hurricane warning and what the different categories of hurricane strengths mean.

June 24, 2013; 7:12 AM • by RVANews staff

The Atlantic hurricane season runs annually from June 1st to November 30th and includes the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico. While Richmond isn’t as threatened by hurricanes as cities in Florida or Louisiana, it’s still good to know the different categories of hurricanes and the difference between a hurricane watch and warning.

— ∮∮∮ —

Watch vs. Warning

The difference between a hurricane watch and a hurricane warning is very important. The National Weather Service uses the terms to convey how prepared and alert people should be.

Here’s what you need to know:

Hurricane watch: Be on guard! A watch means that current weather conditions suggest hazards may occur. Watches are issued 48 hours in advance of the anticipated onset of tropical-storm-force winds (>39 mph).
Hurricane warning: Means hazardous weather is imminent! It is a) either occurring at the moment or b) will occur at any moment. Warnings are issued 36 hours in advance of the anticipated onset of tropical-storm-force winds.

Heeding both watches and warnings is important, but you should give warnings special attention.

— ∮∮∮ —

Classifying hurricanes

When a Tropical storm (sustained winds from 39-73 mph) hits winds at 74 mph, it becomes a hurricane.

There are five different hurricane categories, each measured by their increasing severity. Here’s how they’re classified under the Saffir-Simpson Hurricane Wind Scale (SSHWS) developed in 1971:

Category one: Very dangerous winds will produce some damage • 74-95 mph winds
Category two: Extremely dangerous winds will cause extensive damage • 96-110 mph winds
Category three: Devastating damage will occur • 111-129 mph winds
Category four: Catastrophic damage will occur • 130-156 mph winds
Category five: Catastrophic damage will occur • 157> mph winds