WILMINGTON, N.C.,  - Hurricane Florence, on track to become the first Category 4 storm to make a direct hit on North Carolina in six decades, howled closer to shore on Tuesday, threatening to unleash deadly pounding surf, days of torrential rain and severe flooding.

Fierce winds and massive waves are expected to lash the coasts of North and South Carolina and Virginia even before Florence makes landfall by early Friday, bringing a storm surge as much as 13 feet (4 meters), the National Hurricane Center in Miami warned. Catastrophic floods could follow if the storm stalls inland, it said.

Although Florence was still days from arrival, authorities took extraordinary measures to move people out of harm's way. More than 1 million residents have been ordered to evacuate from the coastline of the three states, while university campuses, schools and factories were being shuttered.

Packing maximum sustained winds of 140 miles per hour (225 km per hour), the storm ranked as a Category 4 on the five-step Saffir-Simpson hurricane scale and was expected to grow stronger and larger over the next few days, the NHC said.

"This storm is a monster," North Carolina Governor Roy Cooper said. "Even if you've ridden out storms before, this one is different. Don't bet your life on riding out a monster."