A Late Polar Vortex Could Bring Record Cold Temperatures to Northeastern U.S.

The reason? The polar vortex is heading south, bringing with it potentially record-low temperatures for May, CNBC explained. BAM Weather meteorologist Ryan Maue said that more and more scientists are beginning to link weather swings like this one with the climate crisis.

“This is not just some random one-off weather event but an obvious trend toward hyper-extreme atmospheric circulations outside the normal bounds of what we typically experience in May,” Maue told CNBC. “It’s not always hotter and drier with rapid climate change, but also colder and wetter.”

The cold weather is coming because part of the polar vortex will separate from its circulation over the Arctic and dip down over the eastern Great Lakes and New England, The Washington Post’s Capital Weather Gang explained.

This will likely break records for upper-air temperatures, leading to readings of negative 30 degrees Fahrenheit at the 500-millibar level (about 18,000 feet above sea level) over upstate New York, northern Pennsylvania, and Lakes Erie and Ontario.

“Of course, no one lives at the 500 millibar pressure level in this region, but meteorologists look to this temperature as an indication of how unusually cold is an air mass,” Matthew Cappucci wrote for The Washington Post. “With air that cold upstairs, it’s no surprise that surface temperatures are going to be chilly as well.”

On the surface, record-low daily maximums could reach Boston, Providence, Rhode Island and Hartford, Connecticut. Other places could also report record lows for May, as temperatures in the mid-20s are forecast for Detroit and Pittsburgh, CNBC reported.

Cold temperatures will be most extreme east of the Rockies, over the Great Lakes and in the Northeast, where they could be as much as 20 to 25 degrees below seasonal highs.

However, it could freeze as far south as northern Georgia and in the higher elevations in the Carolinas, The Washington Post reported.

It could also snow over the Appalachian Trail from North Carolina to Maine and in New England. While May snows have been recorded with similar weather patterns in places like Buffalo, New York and Pittsburgh, this weekend’s snowfall is predicted to be more widespread, AccuWeather reported. It could cover a 500-mile stretch from Ohio to New England, which AccuWeather said was unusual.

Scientists are investigating whether the Arctic’s rapid warming is making it more unstable, pushing cold air further south, CNBC reported. A 2018 study found that there had been more times when the polar vortex had weakened in the winter over the last 37 years.

“The cold is very unusual,” Maue told CNBC. “It is difficult to pinpoint the cause-and-effect or correlation-causation with extreme weather events and climate change. But changes in the behavior of the jet stream are becoming more accepted by scientists looking for physical reasoning behind what we are seeing on weather maps.”

While the cold snap may make social distancing easier, it could be a challenge for those who have been prompted by coronavirus lockdowns to try home gardening.

“Get ready to cover or bring in any sensitive plants you bought during the surge of warm weather this past weekend,” Paul Pastelok, AccuWeather’s top long-range forecaster, said.

He warned that the cold temperatures could have a negative impact on new or sensitive plants, orchards and vineyards.