The intensity of a hurricane is measured by the Saffir-Simpson Hurricane Wind Scale.
This rates the storms from one to five based on sustained wind speed and the potential property damage those winds can cause.
The lowest category storm, a CAT one, is considered minor, with sustained winds of 74 to 95 miles an hour.
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Damage is minimal, primarily confined to trees and power lines. A CAT 2, with 96 to 110 mile per hour sustained winds, causes extensive damage.
We see roof and siding damage to homes, many trees uprooted. Now a Category 3 is considered a major hurricane, with 111 to 129 mile per hour sustained winds.
This causes devastating damage including roofs blown off of homes and widespread flooding. A CAT 4 packs sustained winds of 130 to 156 miles per hour.
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This intensity causes catastrophic damage.
The strongest storm, a CAT 5 is even more intense.
A Category 5 storm has sustained winds of 157 miles an hour or greater.
It can flatten entire communities of well-constructed homes and leave the area uninhabitable for weeks or even months.
See more stories and videos about hurricanes and Hurricane Dorian here.
How is the strength of a hurricane measured?