An Arctic cold front is poised to sweep across parts of the United States, bringing with it record-breaking low temperatures and dangerous wind chills that are expected to persist throughout the coming week, meteorologists say.
This impending cold snap marks the tenth time this winter that the polar vortex has extended southward, according to Judah Cohen, seasonal forecast director at Atmospheric and Environmental Research. “In a normal winter, it happens maybe two or three times,” Cohen said.
This winter has seen extremes from a rare snowfall in New Orleans to devastating wildfires in Southern California.
Having so many polar vortexes—circulation of frigid air typically confined to the Arctic region—is unusual, according to Ryan Maue, a private meteorologist and former National Oceanic and Atmospheric Administration (NOAA) chief scientist.
“Everything, all the stars align, all the wind directions in the atmosphere are dragging the cold polar air out of the Canadian Arctic,” Maue said. “It’s the depths of winter. Everything signals extreme biting, winter cold.”
The Arctic air is expected to first impact the northern Rockies and northern Plains by Saturday before spreading across parts of the United States east of the Rockies. By next week, forecasts predict that 89 percent of the contiguous United States will experience temperatures below freezing, with 27 percent of the Lower 48 will plunge below zero degrees Fahrenheit, according to the National Weather Service.
Maue’s calculations suggest that the average low temperature for the Lower 48 states could reach a bone-chilling 14 degrees Fahrenheit by Wednesday.
The central United States will likely bear the brunt of this cold front. Zack Taylor, a meteorologist at the National Weather Service’s Weather Prediction Center, said that Kansas, Nebraska, Missouri, and Iowa will likely face the coldest temperatures, potentially dropping 35 degrees Fahrenheit below normal for this time of year. Taylor mentioned the possibility of storms accompanying the cold front, potentially bringing flooding and heavy snow.
Weather models from the NOAA predict below-zero temperatures in Colorado, Nebraska, South Dakota, North Dakota, Wisconsin, Michigan, Minnesota, Kansas, Missouri, Illinois, Oklahoma, Iowa, Wyoming, and Montana.
Wind chill factors are expected to worsen the already frigid conditions. The National Weather Service predicts that almost every state, excluding Hawaii, California, and Florida, will experience wind chills of 20 degrees or below at some point next week.
Cohen explained that a particular type of polar vortex behavior, known as “stretching,” varies from the more commonly known sudden stratospheric warming events. During a stretching event, the polar vortex remains intact but extends southward, often affecting the United States more than Europe.
The frequency of these stretching events this winter has caught the attention of climate scientists. Laura Ciasto, a meteorologist specializing in the polar vortex at NOAA’s Climate Prediction Center, said that while the current situation is “interesting,” it is “not unprecedented.”
