Remember in the mid-1990s when we couldn’t stop talking about El Niño? Well, we’re doing the same thing now with the polar vortex.
Yes, the polar vortex is back, and according to The Washington Post, it could make for a wild winter for much of the Northern Hemisphere in January, particularly for the Eastern United States.
This extra brisk winter forecast comes courtesy of Judah Cohen, a climate researcher at Atmospheric and Environmental Research, a private meteorological research and risk analysis firm that provides data to government agencies like NASA and the Department of Defense. Cohen studies polar vortex conditions and prediction models every day, looking for potential disturbances that could turn a normal winter into a harsh one.
The vortex, in case you need a reminder, is a large area of low pressure located about 60,000 feet up on the atmosphere over both the poles. That’s the polar part. The vortex part describes the counter-clockwise flow of air that keeps the cold polar air up at the poles. Sometimes, however, that flow of air is disrupted, either by the winds changing direction or stopping entirely. Either of these events allows the vortex area to warm and the cold polar air goes south, causing frigid conditions in much of North America, Europe and Asia.
Sometimes this cold air is trapped by the jet stream and hangs around. Think back to March 2018 when the U.S. experienced a four-punch combo of nor’easters, or Europe getting pummeled in March, and you’ll have an idea of how that cold air can linger.