Tens of millions of Americans braced Sunday for a massive winter storm, expected to bring the heaviest snowfall and coldest temperatures in over a decade to parts of the country.
Kansas, Arkansas, Kentucky and Virginia have declared states of emergency as the storm, driven by a polar vortex, moved east after striking the central United States. Southern states like Mississippi and Florida also warned of dangerous cold and treacherous 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. Sometimes the Arctic polar vortex wobbles and a lobe surges south, blanketing parts of North America with bitter temperatures.
As the storm moved east, around 60 million people, across 30 states from the Plains to the mid-Atlantic, were under weather alerts as a developing low-pressure system threatened heavy snow and crippling 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 jet transporting the Kansas City Chiefs, according to the Associated Press news agency.
And an 18-mile stretch of Interstate 70 in Kansas was shut down as blizzard conditions threatened up to 14 inches of snow and 40 mph wind gusts, with warnings in effect until early Sunday, according to the National Weather Service.
The service predicts historic precipitation for parts of Kansas and Missouri, forecasting over 15 inches of snow from northeastern Kansas into north-central Missouri — the region’s heaviest snowfall in a decade.
The NWS warned of “considerable disruptions to daily life,” including “dangerous or impossible driving conditions and widespread closures,” making travel “very difficult to impossible” through Sunday.
Cincinnati, Chicago and St. Louis have treated roads in advance of the storm and prepared warming centers.
Scattered snow showers developed across the Northern Plains Saturday afternoon and through the evening. More than 2 million people were covered by a blizzard warning for most of Kansas and a large part of Missouri on Sunday morning, according to the weather service.
Such a warning alerts residents to a likelihood of reduced visibility of 1/4 mile or less and sustained winds of at least 35 mph.
Sunday is expected to bring a severe weather risk across the lower Mississippi Valley, putting 7 million people at risk for tornadoes, damaging wind and hail in cities including Jackson, Mississippi; and Baton Rouge, Shreveport and Lake Charles, Louisiana.
As the storm advances east, millions more Americans are bracing for record-low temperatures, forecasters warn.
Snow will arrive in the mid-Atlantic and central Appalachians overnight into Monday morning. These showers will linger through Monday, ending by Tuesday morning as the system moves offshore.
Washington, D.C., Baltimore, and Philadelphia are among the major cities preparing for snowy and icy conditions from Sunday into Monday, with parts of Virginia expecting 5-12 inches of snow.
Meanwhile, severe thunderstorms could hit southern states unaccustomed to severe cold, including Arkansas, Louisiana, and Mississippi.
From coast-to-coast Saturday, weather-related flight delays were estimated at almost 7,000.
At the western end of the low pressure system, Denver International Airport led the globe in delayed flights, with nearly half its departures on Saturday leaving late, according to FlightAware.
Major airlines, including American, Delta, Southwest, and United, are waiving change fees ahead of likely flight disruptions.
In the wake of this system, a significant drop in temperatures is anticipated for the eastern two-thirds of the country. Highs will drop 10 to 25 degrees below average starting Sunday and lasting through Friday. Highs will range from the single digits and teens across the Plains and Midwest, and in the 20s to 30s in the mid-Atlantic and Northeast.
The most extreme temperatures will be in the northern Plains, where overnight lows will dip as low as minus 20, with wind chill values around minus 40. Cold weather advisories are in place from eastern Montana through Minnesota.
