January has already been colder than average in most states east of the Rocky Mountains for the first time in two years – and now, more frigid air is coming.
A lobe of the polar vortex, a stormy ring that typically keeps the coldest air locked up near the North Pole, will dip southward into the United States this weekend into next week.
Polar air masses from Siberia are forecast to arrive in the northern Rockies on Saturday, before rapidly moving south and east and encompassing much of the United States by Monday.
This will spell dangerously cold temperatures – as cold as minus-20 to minus-30 in some states – and raises the potential for new storms to form as the icy air clashes with the warm, moist air of the Gulf of Mexico and the western Atlantic Ocean.
After a slow start to the snow season in December, parts of more than 15 states now have twice their average season-to-date snowfall. This comes after two big winter storms crossed the country during early January.
More storms over the next week could add to these notable snow totals.
Where it could be stormy
A disturbance may form along the Mid-Atlantic coast on Sunday and could cause a snowy end to the weekend for areas from Washington, D.C., to Boston.
While it’s not expected to be a lot of precipitation, enough snow may fall to make shovelling and plowing necessary. Temperatures on Sunday night will be in the teens across the same region. If it snows, icy spots could linger into the Monday morning commute. In D.C., early forecasts suggest Monday’s presidential inauguration could be the coldest since 2009. There’s also a chance that it will be the windiest inauguration in 40 years.
Forecast details depend on how quickly a cold front moves along the Eastern Seaboard over the weekend.
Faster movement will cause the storm to form farther offshore and cause little impact, while slower movement will cause the storm to form farther inland and feature more widespread snow.
There will be several more chances for storms to develop next week.
On Monday, heavy lake-effect snow could develop near the Great Lakes, lingering for a few days.
Meanwhile, another snowstorm may form in Colorado, New Mexico and the southern Plains. This system has the potential to evolve into a major winter weather-maker for Texas and the Deep South from Monday through Wednesday, spreading snow and ice unusually far south.
Places that were affected by last week’s winter storm, such as Dallas and Atlanta, could be hit by more wintry weather in the week ahead.
With the storm’s puzzle pieces still thousands of miles away from the United States in the Arctic, it will be a few more days before forecast details become clearer.
Early indications are that February may turn out to be a snowier-than-normal month for many Northern states.
How cold it may get
More than 105 million people in the United States could experience subzero temperatures in the next two weeks – covering around 40 states.
The most unusually cold air in the Northern Hemisphere will move into the Plains and Midwest this weekend as the polar vortex lobe zaps the country like a jellyfish tentacle.
Temperatures may be as low as minus-20 to minus-30 in parts of Idaho, Utah, Montana, Wyoming, Colorado, the Dakotas, Minnesota, Wisconsin and Michigan on Monday and/or Tuesday morning.
Although conditions will be undeniably frigid, low-temperature records in the area are even colder. The record low in Minneapolis and Fargo, North Dakota, on Jan. 21 is minus-41, set back in 1888. These, and others, are unlikely to be broken.
On Wednesday, the Arctic air mass will probably be centred near the East Coast, possibly causing the coldest temperatures of the winter so far from Detroit to Washington, D.C., and Boston.
And it won’t just be the air temperatures – the wind chill will make it dangerously cold. Wind chill temperatures of minus-30 to minus-40 may occur in parts of the northern Plains and Upper Midwest early next week.
Frostbite is possible in 10 to 20 minutes on exposed skin under such harsh conditions. Any drop in temperature to this level can be dangerous and deadly, and associated risks should be taken seriously, especially for vulnerable populations. In its outlook about the cold weather, the National Oceanic and Atmospheric Administration said expected temperatures pose “a great risk of hypothermia and frostbite to exposed skin.”
By Wednesday morning, wind chills could range from minus-10 to minus-20 in the Northeast and Mid-Atlantic.
How the chill compares to January 2014
Many people across the United States may recall the polar vortex episode of early 2014. For the Midwest, it turned out to be the coldest winter in over 30 years. In Washington, D.C., January 2014 was the coldest in decades by many counts.
It also turned out to be a year when the polar vortex, a natural phenomenon that develops in the polar regions during winter, got much attention.
Although the term polar vortex may seem relatively new, it isn’t. Disruptions of the vortex were first written about by German meteorologist Richard Scherhag in 1952 – over 70 years ago.
So how does the upcoming cold spell compare to the notorious one 11 years ago?
In January 2014, over 140 million people across about 40 states experienced subzero temperatures. This year, that number is likely to be lower, with the latest projections suggesting that around 105 million people in around 40 states will be affected.