Millions face snow chaos as ‘bomb cyclone’ hits Northeast

Blizzard warnings were in effect for millions of Americans Thursday as a winter storm threatened the entire Northeast with heavy snow and gusty winds in what forecasters called a “bomb cyclone.”

New York could see up to 8 inches of snow and wind gusts as high as 50 mph, the National Weather Service said. The city’s schools will stay closed and airports are already crippled by cancellations.

The advancing storm hit the southern U.S. Wednesday — starting in Florida, where Tallahassee saw its first measurable snowfall in 28 years — triggering emergency declarations and power outages across Georgia and the Carolinas.

As it moves north, it is rapidly strengthening through a process called bombogenesis, and comes amid a sustained period of brutally cold weather linked to the deaths of at least 20 people in the U.S. since Dec. 26.

Blizzard warnings were in effect Thursday all along the coast from northeastern North Carolina right through to New England, where a storm surge of up to 3 feet, accompanied by chunks of ice, was predicted to cause coastal flooding.

Heavy snow was forecast for the morning commute in New York and Philadelphia and in Washington D.C., where federal agencies were preparing to begin work up to two hours later than scheduled.

Related: What in the world is bombogenesis?

Travelers were urged to check with their carriers before heading to the airports; more than 90 percent of Thursday’s flights at La Guardia were already canceled, and more than 70 percent of flights at Newark Liberty and 20 percent of JFK, officials said. Amtrak said it would operate a modified schedule between New York and Boston.

Massachusetts Gov. Charlie Baker urged people to stay off roads and stay indoors, saying he was “anticipating white-out conditions” for part of Thursday. Earlier, officials announced that all Boston public schools would be closed due to the impending weather.

Related: Detailed snow predictions for New York, New Jersey area

The storm already turned parts of the South into a winter wonderland on Wednesday, including in Florida where pictures of snowfall on sandals and swimming pools were shared on social media. Three inches of snow were recorded in Charleston, South Carolina.

Georgia Gov. Nathan Deal declared a state of emergency in his state for 28 counties, and in North Carolina, Gov. Roy Cooper declared a state of emergency for all eastern and several central counties.

Image: Vehicles move along a snow and ice covered Interstate 26, near Savannah, Ga., Wednesday. Image: Vehicles move along a snow and ice covered Interstate 26, near Savannah, Ga., Wednesday.

Vehicles move along a snow and ice covered Interstate 26, near Savannah, Ga., Wednesday. Robert Ray / AP

Power outages affected tens of thousands in the South. As of Wednesday evening there were still more than 12,400 Georgia Power customers, more than 10,200 Florida Power & Light customers and more than 2,700 South Carolina Electric & Gas customers affected, the utilities reported.

A storm is considered a “bomb” when the pressure drops rapidly — at least 24 millibars in 24 hours. This storm looks like it will intensify at twice that rate, said Bob Oravec, lead forecaster at the National Weather Service’s Weather Prediction Center.

Meteorologist Ryan Maue, who helped popularize the term “polar vortex” in 2014, told the AP: “Bombogenesis is the technical term. Bomb cyclone is a shortened version of it, better for social media. The actual impacts aren’t going to be a bomb at all. There’s nothing exploding or detonating.”

Alastair Jamieson reported from London. Kalhan Rosenblatt and Daniella Silva reported from New York.