NEW YORK (AP) — An arctic blast has brought extreme cold, heavy snow and violent winds to much of the United States — just in time for the holidays.
Weather system dubbed ‘bomb cyclone’ disrupts travel Causing dangerous winter conditions. Where is this winter weather coming from and what’s next?
what’s happening?
A cold front is descending from the North Pole and temperatures are dropping rapidly.
Bob Olavek, chief forecaster for the National Weather Service in College Park, Maryland, said many parts of the United States will experience lower average temperatures.
The National Weather Service predicts temperatures could drop by more than 20 degrees Fahrenheit (11 degrees Celsius) in just a few hours.
Wind chill temperatures can drop to dangerous lows well below zero, enough to cause frostbite within minutes. In parts of the plains, wind chill can drop to minus 70 degrees Fahrenheit (minus 57 degrees Celsius).
The National Weather Service warns of blizzard conditions in the plains, upper Midwest, and Great Lakes as strong winds lift snow.
Who is Affected?
Ryan Maue, a private meteorologist in the Atlanta area, says that almost everyone east of the Rocky Mountains—about two-thirds of the country—will see extreme weather.
Most of the West Coast will be sheltered from the cold, but the Arctic front is expected to pass through Florida all the way east and south.
Oravec said heavy snow and strong winds could be bad news for air travel.
And for those planning to travel during the holiday season, “you’re going to have a pretty serious whiteout,” Maue warned.
how long does it last?
The weather system is expected to bring some major “weather whiplash,” said Judah Cohen, a winter storm expert in atmospheric environment research.
The cold doesn’t last long. “Everything will come back,” Cohen said after a dramatic drop in temperatures that kept temperatures low for about a week.
Shortly after Christmas, temperatures are expected to begin to warm again, moving from west to east.Most parts of the U.S. likely to remain near-normal through the end of the year
why did this happen?
It all started farther north, according to Maue, as frigid air gathered on the snow-covered ground of the Arctic.
Then the jet stream—the turbulent air currents in the middle and upper layers of the atmosphere—started pushing this cold pool into the United States.
As this arctic air pushes into the warm, moist air ahead, the system can quickly evolve into severe weather. This includes what are known as “bomb cyclones,” which are rapidly developing storms. Atmospheric pressure drops rapidly in 24 hours.
These severe weather events usually occur in bodies of water with a lot of heat and moisture to feed the storms, says Maue. However, on rare occasions bomb cyclones could be seen forming on land due to the large amount of cold air that passed through.
Is this normal?
The storm is undeniably strong, but “it’s not unprecedented for the winter season,” Oravec said.
It is quite normal for cold air to accumulate in the winter. But changes in the jet stream this week have pushed air more southeast than normal, clearing the freeze across the country and making storm conditions more intense, Oravec said.
The United States probably won’t reach the record-breaking lows seen in the 1983 cold snap or the 2014 polar vortex, Maue said.
Still, “for most people alive, this will be a memorable, top 10 extreme cold event,” Maue said.
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