Read the latest on the bitter cold along the East Coast with Friday’s live updates.

After battering the South and whipping up the Mid-Atlantic coast, a blizzard propelled by hurricane-strength winds lashed the Northeast on Thursday, grounding flights, shuttering schools, flooding buildings and sending squalls of snow into the tunnels of New York City’s subway system.

In downtown Boston, a three-foot tidal surge flooded a subway station and turned a popular tourist area into a slushy tundra. In New York, the two major airports stopped flights and cars slid off glazed roads. And in Virginia, more than 40,000 residents and businesses lost power.

The storm, called a “bomb cyclone” by some meteorologists for how quickly the barometric pressure fell, created winds that topped 75 miles per hour in Nantucket and 65 miles per hour on Long Island, tearing the roof off a gas station and making some crossings impassable for trucks.

As treacherous as it was, elected officials warned that the storm was a prelude to worse misery, with days of subzero wind chills ahead that could freeze snowy roads and put homeless people in grave danger.