Most of the US is bracing for a prolonged stretch of frigid weather and a massive winter storm that could wreak havoc on roads and power grids over the next several days.
At least 170 million Americans are under winter weather alerts. “Bitterly cold temperatures and dangerously cold wind chills” will linger even after the storm is done dumping heavy snow, sleet, and freezing rain across the Southern Rockies all the way to New England through Monday, the National Weather Service (NWS) warned Friday. Forecasters expect low temperatures to break numerous records, with wind chills as frigid as minus 50 degrees Fahrenheit in the Northern Plains.
It’s been a bit difficult for forecasters to get a good sense early on of where this storm will be headed and who will be hardest hit. It’s driven by complex factors scientists are still working to better understand, starting with bitter-cold Arctic air set on a collision course with a weather system moving inland from the Pacific Ocean that’s loaded with moisture.
“It’s not setting up like a normal winter storm.”
“It’s not setting up like a normal winter storm,” says Andrea Lopez Lang, an associate professor and atmospheric scientist at the University of Wisconsin–Madison. The effects could be particularly long-lasting. And with such a large swath of the US affected, there is likely to be a wide range of effects from place to place. “Make sure that you’re paying attention to your local forecasts, because the impacts can be very different, even though this is all part of the same system,” Lopez Lang advises.
Parts of the Arctic are enveloped in darkness for months at a time in the winter, allowing the air to get consistently colder. Normally, a current of strong winds called the jet stream keeps that Arctic air from drastically affecting temperatures further south. But a large high-pressure system has allowed the jet stream to dip, letting extremely cold air reach further down into Canada and the US.
When that moisture-packed weather system from the Pacific moves far enough inland to crash into the jet stream, the combination of wet and cold conditions can create a cascade of hazards from snow and freezing rain. The latter, which happens when raindrops freeze upon hitting a surface, allows ice to build up on roads and infrastructure. The persistent cold after the storm prolongs the risk.
“The storm will cause significant to locally catastrophic ice accumulations with the potential for long-duration power outages, extensive tree damage, and extremely dangerous or impassable travel conditions,” NWS says in its forecast. Ice is heavy, which could bring down power lines and leave some homes without electricity or heat in an outage. The deadly cold spell in Texas in 2021 left millions of homes without heat after ice clogged up gas pipelines.
It’s too early to say exactly what role climate change might play in this particular storm. There were unique triggers for this storm, however, that might have been influenced by a shifting climate. For one, the atmosphere can hold more water vapor, which can lead to heavier downpours with storm systems.
The jet stream has also gotten wackier. The difference in temperature between the tropics and the poles historically has kept it relatively consistent. But the Arctic is warming even faster than the rest of the planet. And as the difference in temperature becomes less pronounced, the more the jet stream buckles — allowing Arctic air to penetrate further south when the jet stream meanders.
Severe cold snaps like this one have actually become less common with rising global temperatures. That can pose its own challenges because communities might not be as prepared to cope with them when they do arrive, experts tell noti.group. And they stress that it’s important to understand that climate change can influence extreme events of all kinds, not only heat.
“People say, ‘Oh, well, it’s really cold or we’re getting a lot of snow — how is the world warming?’ Climate change is an increase in the baseline temperatures, but it’s also an increase in extremes from both ways,” says Kaitlyn Trudeau, a senior research associate at the nonprofit Climate Central. “It can make more extreme cold outcomes; it can make more extreme warm outcomes … judging climate change by a cold storm is like judging a baseball season by a single inning.”
Lopez Lang is bracing for the impact of the storm in Wisconsin, both on her home and her work. Weather permitting, she and her colleagues are planning to fly into the storm as it makes its way off the east coast to study how it evolves. They’ll be aboard a NASA aircraft taking measurements of water vapor, temperature, and other factors influencing this event. They want to study the structure of the storm to better understand what happens when a weather system like the one causing trouble this week meets the jet stream.
After all, some of the initial questions over how the storm would unfold this week stem from forecasters trying to figure out when and how that merge would occur. “These mergers [are] big components of the uncertainty in forecasts,” Lopez Lang says. “So we want to make sure that we’re observing them really well so that we can get the best data to make the best forecasts.”
[Notigroup Newsroom in collaboration with other media outlets, with information from the following sources]
