"Get to safety, and stay there," North Carolina Gov. Roy Cooper said in a Thursday news conference.
As of 2 p.m. Thursday, the Category 2 storm is about 60 miles south of Myrtle Beach, South Carolina, and 115 miles south-southwest of Wilmington, North Carolina, headed north-northeast at 8 mph. The storm has maximum sustained winds of 110 mph.
The coasts of both Carolinas are under a Hurricane Warning.
At 11 a.m. Wednesday, the National Hurricane Center extended the area under warning to stretch from north of the Savannah River to the North Carolina-Virginia border, as well as Albemarle and Pamlico Sounds.
"We will be ready and we will not underestimate the damage this storm can cause," North Carolina Governor Roy Cooper said in a Wednesday news conference. "... Today is the day to finish preparing."
A mandatory evacuation order is already in effect for North Carolina's barrier islands.
Forecasters say the hurricane may begin moving more to the northeast by Thursday night.
Through the day, Dorian will continue moving toward the South Carolina coast before moving near or over the North Carolina coast tonight and Friday.
The center of Dorian is forecast to move near or over the coast of South Carolina and North Carolina Thursday through Friday morning.