Here's what you need to know about the intense cold wave that threatens the US: it will produce snowfall, significant ice and frigid temperatures, scientists predict.
A major winter storm will produce heavy snow, significant ice and frigid temperatures, beginning in the central United States on Saturday and moving east over the next few days, according to the National Weather Service.
Here's what you need to know about the storm that is expected to affect millions in the eastern two-thirds of the country:
A major winter storm brewing
A large system made landfall on the West Coast on Friday afternoon, bringing rain to the Pacific Northwest and snowfall is expected in the Cascade Mountains, according to forecasters.
The system will generate a significant winter storm from the Central Plains to the Mid-Atlantic this weekend into early next week.
Snow in the central plains heading east
By Saturday night, widespread heavy snow is likely in areas between central Kansas and Indiana, especially along and north of Interstate 70, where there is a high chance of at least 8 inches (20.3 centimeters). inches).
For places in the region that typically experience the heaviest snow accumulations, it could be the heaviest snowfall in at least a decade, forecasters said.
The storm will then move into the Ohio Valley, where roads could become impassable. It will reach the mid-Atlantic states on Sunday and Monday.
Blizzard conditions
Wind gusts above 35 miles per hour (56 kilometers per hour) and heavy snow accumulations could lead to blizzard conditions, particularly in Kansas and nearby parts of the Central Plains by Sunday morning.
Such conditions could make driving dangerous or impossible and increase the risk of becoming stranded.
Freezing rain from eastern Kansas to the Ozarks
Dangerous sleet and freezing rain, particularly damaging to power lines, is also expected to begin Saturday from eastern Kansas to Missouri, Illinois, Indiana and much of Kentucky and West Virginia.
Hazardous travel conditions are expected with power outages in areas with more than a quarter-inch of ice accumulation.
“It's going to be a disaster, a potential disaster,” said private meteorologist Ryan Maue.
Frigid Arctic air even in Florida
Starting Monday, hundreds of millions of people in eastern parts of the country will experience dangerously cold air and cold wind chills, forecasters said.
Temperatures could be 7 to 14 degrees Celsius (12 to 25 degrees Fahrenheit) colder than normal as the polar vortex spreads from the high Arctic.
“This could lead to the coldest January for the United States since 2011,” Dan DePodwin, AccuWeather's director of forecast operations, said Friday, noting there could be up to a week or more of “temperatures well below the historical average.”
The biggest drop below normal will likely be centered over the Ohio Valley, but the cold will extend south to the Gulf Coast, said Danny Barandiaran, a meteorologist with the National Weather Service's Climate Prediction Center.
A hard freeze is even expected in Florida, he added.
“The wind chills are going to be brutal,” said Jennifer Francis, a climate scientist at the Woodwell Climate Research Institute. “Just because the globe is warming doesn't mean these cold extremes are going away.”
The cause could be a rapidly warming Arctic
The brutal weather may be triggered in part by a rapidly warming Arctic, a reminder that climate change is intensifying weather extremes, explained Judah Cohen, director of seasonal forecasting at the private firm Atmospheric Environment and Research.
The polar vortex—ultracold air that spins like a top—usually stays above the North Pole, but sometimes extends to the United States, Europe or Asia, causing intense doses of cold.
Cohen and colleagues have published several studies showing an increase or shift of the polar vortex. Cohen and others published a study last month attributing the cold outbreaks in part to changes in an Arctic that is warming four times faster than the rest of the globe.