Tens of millions of Americans prepared Sunday for a massive winter storm, which is expected to bring the heaviest snowfall and coldest temperatures in more than a decade to parts of the country.
Kansas, Arkansas, Kentucky and Virginia declared states of emergency as the storm, driven by a polar vortex, moved east after hitting the central United States. Southern states like Mississippi and Florida also warned of dangerous and dangerous cold conditions, according to the National Weather Service.
A polar vortex is an area of low pressure and cold air that swirls like a wheel around each of Earth’s two polar regions. Occasionally, the Arctic polar vortex wobbles and a lobe heads south, blanketing parts of North America in freezing temperatures.
As the storm moved east, about 60 million people in 30 states from the Plains to the mid-Atlantic were under weather alerts as a developing low pressure system threatened heavy snow and paralyzing ice over the next three days.
Travel disruptions
Kansas City International Airport briefly closed Saturday as crews cleared runways, delaying dozens of flights, including a charter plane carrying the Kansas City Chiefs, according to the Associated Press news agency.
And an 18-mile stretch of Interstate 70 in Kansas was closed as blizzard conditions threatened up to 14 inches of snow and wind gusts of 40 mph, with warnings in effect through Sunday morning, according to the National Weather Service.
The service is forecasting historic precipitation for parts of Kansas and Missouri, forecasting more than 15 inches of snow from northeast Kansas to north-central Missouri — the region’s heaviest snowfall in a decade.
The NWS warned of “considerable disruption to daily life,” including “unsafe or impossible driving conditions and widespread closures,” making travel “very difficult or impossible” through Sunday.
Cincinnati, Chicago and St. Louis treated roads ahead of the storm and prepared warming centers.
Scattered snow showers developed across the northern Plains Saturday afternoon and throughout the evening. More than 2 million people were covered by a blizzard warning for most of Kansas and much of Missouri as of Sunday morning, according to the weather service.
Such a warning warns residents of a likelihood of reduced visibility of 1/4 mile or less and sustained winds of at least 35 mph.
A severe weather hazard is expected in the Lower Mississippi Valley on Sunday, putting 7 million people at risk of tornadoes, damaging winds and hail in cities including Jackson, Mississippi; and Baton Rouge, Shreveport and Lake Charles, Louisiana.
As the storm moves east, millions more Americans are bracing for record temperatures, forecasters warn.
Snow will arrive in the mid-Atlantic and central Appalachians overnight Monday morning. These showers will persist through Monday and end Tuesday morning as the system moves offshore.
Washington, D.C., Baltimore and Philadelphia are among the major cities bracing for snowy and icy conditions Sunday through Monday, with parts of Virginia expecting 5 to 12 inches of snow.
Meanwhile, severe thunderstorms could hit southern states unaccustomed to intense cold, including Arkansas, Louisiana and Mississippi.
From coast to coast on Saturday, weather-related flight delays were estimated at nearly 7,000.
At the western end of the low pressure system, Denver International Airport leads the world in delayed flights, with nearly half of its departures Saturday, according to FlightAware.
Major airlines, including American, Delta, Southwest and United, are waiving change fees in advance of likely flight disruptions.
In the wake of this system, a significant drop in temperatures is expected for the eastern two-thirds of the country. Maximum temperatures will drop 10 to 25 degrees below average starting Sunday and continuing through Friday. Highs will be between 10% and 10% in the Plains and Midwest, and between 20% and 30% in the Mid-Atlantic and Northeast.
The most extreme temperatures will be in the Northern Plains, where overnight lows will drop to minus 20, with wind chill values around minus 40. Cold weather advisories are in place from eastern Montana to ‘in Minnesota.
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