GEORGETOWN, Del. — Officials declared a state of emergency in southern Delaware as a coastal winter storm that paralyzed parts of the East Coast with blizzard-like conditions brought howling winds and more than 10 inches (25 cm) of snow to the state.

In addition to declaring a state of emergency for Sussex County on Thursday, Gov. John Carney authorized the Delaware National Guard to assist state and local officials with any necessary response and recovery efforts.

The state of emergency was accompanied by a prohibition on driving on state roads in Sussex County except for people designated as essential personnel. That designation includes emergency workers, utility workers, health care providers, snow removal crews, and food and fuel deliveries.

Meanwhile, state transportation officials warned residents of a prolonged cleanup because of high winds, drifting snow and extremely cold temperatures.

Schools and government offices were closed throughout the state Thursday, and officials warned residents to avoid driving if possible.

Officials in Sussex County said more than 40 cars had been ditched or abandoned since Wednesday night. Carney directed state and local officials to remove abandoned vehicles from roads in affected areas at the expense of vehicle owners.

Snow accumulations in southern Delaware as of midafternoon Thursday included 10.8 inches (27 cm) in Dagsboro, 10 inches (25 cm) in Lewes, and 9.3 inches (23 cm) in Stockley.

Delmarva Power reported about 2, 000 customers without electricity early Thursday afternoon, mostly in northern Delaware, but crews were quickly restoring service to customers.

A blizzard warning was in effect until 7 p.m. for Sussex County, and forecasters warned that winds gusting as high as 40 to 50 mph (65 to 80 kph) would cause whiteout conditions into Friday, with significant drifting of snow through Friday night.

“The public should be prepared for poor conditions to remain well after the snow stops falling late this afternoon,” said Chip Guy, a spokesman for Sussex County government, noting that high winds are forecast through Saturday, and below-freezing temps through the end of the weekend. “So that will mean little to no melting, and what has fallen will blow all around, including back onto roads that DelDOT is working its best to clear.”

The Delaware River and Bay Authority suspended operations for the ferry connecting Lewes, Delaware, to Cape May, New Jersey, on Thursday, citing significant ice accumulation in canals along the Delaware Bay, as well as forecasts for heavy winds.