The latest forecast from the National Hurricane Center has Dorian strengthening into a major Category 3 hurricane with winds of 115 mph by Sunday off the U.S. East Coast.
What does this mean?
A "major" hurricane is any hurricane that's rated as a Category 3, 4 or 5 hurricane on the Saffir-Simpson scale of hurricane intensity. A Category 3 hurricane has maximum sustained winds of from 111 to 129 mph.
The five hurricane categories of the scale are defined solely by wind speed and don't take storm surge, heavy rain or barometric pressure into account. Keep in mind that water – whether through surging ocean waves or driving rain – is often the most destructive part of a hurricane, typically causing more devastation than wind.
If Dorian hits as a Category 3, "devastating" wind damage will occur, according to the National Hurricane Center.
"There is a high risk of injury or death to people, livestock and pets due to flying and falling debris," the hurricane center warned.
Poorly constructed frame homes can be destroyed by the removal of the roof and exterior walls and unprotected windows will be broken by flying debris. Well-built frame homes can experience major damage involving the removal of roof decking and gable end, according to the hurricane center.
"Many trees will be snapped or uprooted, blocking numerous roads," the hurricane center said. "Electricity and water will be unavailable for several days to weeks after the storm passes."
Since 1851, 13 major hurricanes have made landfall along the east coast of Florida, according to Colorado State University hurricane expert Phil Klotzbach. The most recent was Hurricane Jeanne in 2004, which killed 28 people and caused $10.3 billion in damage, the National Oceanic and Atmospheric Administration said.
If Dorian strengthens to a Category 4, with wind speeds of 130 mph, the damage could catastrophic, the hurricane center warned: "Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls," the hurricane center said. "Most trees will be snapped or uprooted and power poles downed."
A hit from a Category 4 hurricane means that "power outages will last for weeks to possibly months, and long-term water shortages will increase human suffering. Most of the area will be uninhabitable for weeks or months."
The most powerful storms – Category 5s – destroy a high percentage of homes, often causing total roof failure and wall collapses. Fallen trees and power poles isolate residential areas. Power outages last for weeks or months. And areas can be uninhabitable for the same time frame.
Category 5 hurricanes have wind speeds of 157 mph or greater.
Landfalls from Category 5 hurricanes are exceedingly rare, fortunately. Only four have been recorded in U.S. history, including Hurricane Michael last year. Michael killed 49 people and caused $25.2 billion in damage, NOAA said.
This article originally appeared on USA TODAY: Dorian: Forecast to strengthen into a Category 3 major hurricane