The polar vortex is back in July, bringing record-low temperatures for a large swath of America in the next week.
Forecasters are calling it the polar vortex sequel, or the ghost of the polar vortex, and say it will bring unseasonably cold air that will have Midwest and Northeast residents reaching for their winter coats. A deep pocket of frigid air will be making its way down from the Gulf of Alaska, reaching into the Great Lakes region early in the week and then making its way toward the East Coast.
The polar vortex hitting in July is expected to drop temperatures to between 10 and 30 degrees below average. Highs in the region are expected to reach only the 50s and 60s, with morning lows in the 40s.
The hit is coming at what is normally the warmest time of year. Temperatures in mid-July regularly reach the mid- to high-90s across most of the region that will be affected.
Weather Underground meteorologist Jeff Masters says there are several factors at play in the July polar vortex. He noted that the supertyphoon that hit Japan set into motion a chain reaction that altered the jet stream and helped plunge frigid temperatures into the United States.
“Neoguri will cause an acceleration of the North Pacific jet stream, causing a large amount of warm, moist tropical air to push over the North Pacific. This will amplify a trough low pressure over Alaska, causing a ripple effect in the jet stream over western North America, where a strong ridge of high pressure will develop, and over the Midwestern U.S., where a strong trough of low pressure will form.”
Meteorological experts say polar vortex this July isn’t exactly the same as the one that hit in the winter, bringing record-low temperatures across the United States. Instead of being pulled down from the arctic, this front is being fueled from weather in the Pacific, they note.
The effects of this winter’s polar vortex have already played a role in the rest of the year. Meteorologists say the conditions delayed the spring thaw, making for a wicked pollen season.
“This is truly the gift that keeps giving,” ABC News medical correspondent Dr. Jennifer Ashton said. “Instead of a gradually blooming of everything we normally see on the windshield of our car, it’s all happening at once really setting up a perfect storm for allergy sufferers.”
While the polar vortex in July is plunging the eastern two-thirds of the United States into frigid colds, the west is seeing record warmth that includes drought conditions across the entirety of California.