The monster storm intensified to a Category 4 with 140 mph (225 kph) maximum sustained winds early Monday while it started to lash the Turks and Caicos Islands and the southeast Bahamas, according to the U.S. National Hurricane Center in Miami.

Much of North Carolina’s Outer Banks region is under a tropical storm watch with Hurricane Erin expected to skirt the area Wednesday through Thursday, according to the National Hurricane Center.

Additional strengthening is expected as the storm is forecast to “remain a large and dangerous major hurricane through the middle of this week,” the National Hurricane Center said.

"We cannot put this more bluntly: we now EXPECT there will be times over the next week that N.C .12 becomes impassable due to significant ocean overwash," OBX transportation officials said.

Hurricane Erin strengthened 85 mph in 24 hours to a 160 mph Category 5 hurricane putting in fourth place for rapidly intensifying storms.