Hurricane Classification & Property Damage

5/25/2022 (Permalink)

Reminder: Hurricane season begins on June 1st.

How do we determine the threat of an oncoming hurricane? 

Hurricanes are categorized 1-5 based on the Saffir-Simpson Hurricane Scale. The scale uses maximum sustained wind speed to indicate the threat level of a storm. 

Understanding the threat associated with each category helps homeowners determine which precautions to take, including evacuating from areas vulnerable to storm surges. It also indicates the level of property damage we can expect.

Category One: 74 to 95 mph winds

Damage to shrubbery, tree foliage, poorly constructed structures, and unanchored mobile homes.

Storm Surges 4' to 5' above normal tide levels. Low-lying coastal roads are flooded.

Category Two: 96 to 110 mph winds

Considerable damage to shrubbery. Some trees are blown down. Major damage to poorly constructed structures and roofing materials.

Storm Surge of 6' to 8' above normal tide levels. Low lying escape routes and coastal roads are cut by rising water 7 to 8 hours before the arrival of the hurricane's center.

Evacuation of some shoreline residences and low-lying areas is required.

Category Three: 111 to 130 mph winds

Foliage is torn from trees and large trees are blown down. Damage to roofing materials, windows, and doors is expected. Mobile homes are destroyed and some structural damage to small buildings.

Storm Surge 9' to 12' above normal tide levels. Serious flooding at the coast destroys small structures. Large structures are battered by waves and floating debris. Low lying escape routes are cut off by rising water 9 to 10 hours prior to the hurricane center's arrival. Major erosion to beaches. 

Massive evacuation of all residences within 500 yards of beach and single-story residences on low ground within 2 miles of shore.

Category Four: 131 to 155 mph winds

Shrubs, trees, and signs are blown down. Extensive damage to roofing materials, windows, and doors. Complete failure of roofs on many small residences. Storm Surge 13' to 17' above normal tide levels. Flat terrain 2 feet or less above sea level flooded up to 6 miles inland. Major damage to lower floors of structures near shore due to flooding and battering of waves and debris. Low lying escape routes inland cut by rising water 11 to 12 hours prior to hurricane center arrival.

Category Five: Winds exceeding 155 mph

Damage as above plus the complete failure of roofs on many residential and industrial buildings. Extensive shattering of window and door glass. Many complete building failures and small buildings overturned or blown away. Storm Surge greater than 18' above normal tidal levels. Low lying escape routes inland are cut by rising water 12 to 13 hours before hurricane center arrival. 

Massive evacuation of residential areas on low grounds within 5 to 10 miles of shore is possibly required.

Source: Official U.S. Navy Website