Hurricane Florence has potential to cause "massive damage" to parts of the southeastern and mid-Atlantic United States – and not just in the coastal areas where the storm aims to make landfall on Thursday night, officials warned.

More than 1 million people face mandatory evacuation orders Tuesday in coastal areas of Virginia, North Carolina and South Carolina, as one of the strongest hurricanes to churn toward the eastern seaboard in decades – a Category 4 storm that may approach Category 5 strength – nears shore.

Tropical-storm-force winds are due to reach the coasts of North and South Carolina late Wednesday night, and hurricane-force winds may be felt around noon Thursday, ahead of a landfall likely Thursday night, CNN meteorologist Chad Meyers said.

Powerful storm surges and winds will pose deadly threats, as will long periods of heavy rain.

Beyond the Carolinas and Virginia, the threat of inland flooding extends into next week to parts of Tennessee, Georgia, West Virginia, Ohio, Maryland and Pennsylvania, forecasters said.

“This will be a storm that creates and causes massive damage to our country,” Jeff Byard, Federal Emergency Management Agency associate administrator, said on Tuesday morning.

“It is going to be … a long-term recovery,” Byard said. “This is not going to be a storm that we recover from in days.”

Follow N1 via mobile apps for Android | iPhone/iPad | Windows| and social media on Twitter | Facebook.