Arctic blast sweeps U.S., causes bomb cyclone

NEW YORK — An arctic blast has brought extreme cold, heavy snow and intense wind across much of the U.S. — just in time for the holidays.

The weather system, dubbed a “bomb cyclone,” is disrupting travel and causing hazardous winter conditions. Where is this winter weather coming from, and what’s in store for the coming days?

What’s happening?

A front of cold air is moving down from the Arctic, sending temperatures plunging.

Much of the U.S. will see belowaverage temperatures, said Bob Oravec, lead forecaster for the National Weather Service in College Park, Maryland.

Temperatures may drop by more than 20 degrees Fahrenheit in just a few hours, the National Weather Service

predicts.

Wind chill temperatures could drop to dangerous lows far below zero — enough to cause frostbite within minutes. In parts of the Plains, the wind chill could dip as low as minus 70 degrees Fahrenheit.

Those in the Plains, the Upper Midwest and the Great Lakes were cautioned to expect blizzard conditions as heavy winds whip up the snow, according to the National Weather Service.

Who will be affected?

Pretty much everyone east of the Rockies — around two-thirds of the country — will see extreme weather, said Ryan Maue, a private meteorologist in the Atlanta area.

Though much of the West Coast will be shielded from the cold, the Arctic front is expected to pass east and south all the way through Florida.

Heavy snowfall and intense winds could be bad news for air travel, Oravec said.

And for those planning to hit the road for the holidays, “you’re going to have pretty serious whiteout conditions,” Maue cautioned.

How long will it last?

This weather system is expected to bring some major “weather whiplash,” said Judah Cohen, a winter storm expert for Atmospheric Environmental Research.

The cold isn’t going to stick around for long. After the dramatic plunge that will keep temperatures low for about a week, “everything will snap back to normal,” Cohen said.

Shortly after Christmas, temperatures are expected to start to warm up again, moving from west to east. They are likely to remain near normal through the end of the year in most of the U.S.