Frigid temperatures are expected to affect much of the east-central United States in the coming weeks.
The first of three polar vortex systems is expected to occur this month, according to AccuWeather. A surge of arctic air can create gusts and squalls in certain locations, which can foster more widespread snow-bearing storms.
“This week’s outbreak will likely be the first of three such rounds, with another cold wave likely next week and a third one the week after,” AccuWeather chief long-range meteorologist Paul Pastelok said on the website. “Arctic atmospheric waves will lead to a significant surge in energy demand.”
“This week’s outbreak will probably be the first of three such rounds. There will probably be another cold wave next week and a third one the week after that,” Pastelok added.
Temperatures are very low in December
The upper Midwest and Northern Plains are experiencing sub-freezing temperatures in Canada. Wind chills are expected to reach -10 to -25 degrees on Thursday, December 4, and are expected to continue in the eastern United States through Friday, December 5.
As the leading edge of the polar atmosphere moves southward, blowing snow, snow and larger snow squalls are possible as the front crosses the Great Lakes region and into the northern half of the Appalachians, AccuWeather said.
Don’t see the graphic? Click here to view it.
How do polar vortices form?
The North Pole is covered by the polar vortex, a giant circular upper-air weather system located in the North Pole. This is a normal pattern that tends to include extremely cold climates near the North Pole and is stronger in winter. Parts of the polar vortex can sometimes break or drift southward, bringing frigid weather to the United States, Europe, and Asia. Normally, the jet stream traps the vortices and keeps them there.
In winter, the cold wind can make you feel even colder.
When temperatures start to drop, especially when temperatures dip below or below freezing, cold weather significantly increases the risk of frostbite.
The National Weather Service uses computer modeling to “provide accurate, easy-to-understand, and useful formulas” for calculating wind chill. The index calculates wind speed at 5 feet above the ground (the average height of an adult’s face) while incorporating “heat transfer theory based on heat loss from the body to its surroundings,” according to the NWS.
The Wind Chill Index helps you understand how low temperatures and strong winds can cause frostbite. To determine the wind cooling temperature in the graph below, find the associated wind speed at the top and the outside temperature at the right. You can see the wind chill temperature where they intersect.
Contribution: Doyle Rice/USA TODAY, Cailey Gleezon, Milwaukee Journal Sentinel
Source AccuWeather, National Weather Service, USA TODAY research
