CHARLESTON/SAVANNAH • Hurricane Matthew was downgraded to a post-tropical cyclone yesterday as it struck North Carolina and Virginia with a diminished yet still potent punch, causing flooding and widespread power outages along the United States' Atlantic coast.
The most powerful Atlantic storm since 2007 unleashed torrential rains and powerful winds as it churned slowly north after pummelling the south-eastern coast of the United States, killing at least 11 people in Florida, Georgia and North Carolina since last Thursday and leaving more than two million businesses and homes without power.
Warnings of flash floods were in effect in North Carolina and Virginia, where gusts of 120kmh were recorded.
"The wind is bending the trees to a 90-degree angle in my backyard, I've lost electrical power in my home and the rain is blowing sideways," said occupational therapist Frank Gianinni, 59, from his home in Wilmington, North Carolina.
Forecasters said widespread flooding was possible from heavy rain - 50cm was expected to fall in some areas - along with storm surges and high tides.
"We are looking at very significant flooding. Almost every road in the city is impassable," Virginia Beach spokesman Erin Sutton told the Weather Channel from the city of almost half a million people between Chesapeake Bay and the Atlantic Ocean.
Media showed footage from across the region of motorists and passengers sitting and standing on vehicles stuck in rushing flood waters as crews used swift water boats to rescue the stranded.
In Cumberland county, North Carolina, alone, more than 500 people were rescued by crews, the Weather Channel reported.
Matthew, which days ago briefly topped out as a ferocious Category 5 storm, made US landfall last Saturday near McClellanville, South Carolina, a village 48km north of Charleston that was devastated by a Category 4 hurricane in 1989.
Streets in downtown Charleston were flooded to the tops of tyres on some parked cars.
The National Weather Service reported record-high tides along the Savannah River at the South Carolina-Georgia border, peaking at 3.8m, surpassing those from Hurricane David in 1979.