Understanding How Hurricanes Get Categories

A man reacts in the winds and rain as Hurricane Irma slammed across islands in the northern Caribbean on Wednesday, in Luquillo, Puerto Rico September 6, 2017. REUTERS/Alvin Baez TPX IMAGES OF THE DAY - RC14353ED7A0

After the destruction of Hurricane Harvey, Hurricane Irma has grown to become a gauntlet of it’s own. The Category 4 storm blasted through the Bahamas, Cuba, and many other islands in the Atlantic, and is still expected to hit southern Florida as a Category 5. Governor Rick Scott has urged Floridians, especially those in the Keys and Miami, to evacuate as quickly as possible.

The categories that describe a Hurricane’s strength comes from the Saffir-Simpson hurricane wind scale. Along with describing the five categories, the Saffir-Simpson also describes the qualifications for a tropical storm or a  tropical depression. This scale is used exclusively for hurricanes and other storms that occur in the Atlantic Ocean. The Saffir-Simpson scale relies only on wind speeds to determine a Hurricane’s category–not rainfall, potential flooding, or any other natural events that happen during a Hurricane.

The five categories on the scale are separated by wind speeds, and each classification has a damage expectation attached to it. A Category 1 hurricane has winds at 74-95 miles per hour with minimal damage. A Category 2 has wind speeds at 96-110 mph with moderate damage. Category 3 has wind speeds of 111-130 mph with extensive damage, while Category 4 increases to wind speeds of 131-115 mph with extreme damage. Lastly, Category 5 has winds upwards of 115 mph with catastrophic damage.

According to the National Hurricane Center, Hurricane Irma will affect mainly Florida, but Georgia, Alabama, Tennessee, Arkansas, North Carolina, South Carolina, Kentucky, Virginia, Missouri, Illinois, and Indiana will also experience some winds and rain.

Next: Terminology Regarding Hurricanes