Most of the U.S. is preparing for a long stretch of bitterly cold weather along with a significant winter storm that could disrupt roads and power grids in the coming days. Over 170 million Americans are under winter weather alerts. The National Weather Service (NWS) warned that “bitterly cold temperatures and dangerously cold wind chills” will persist even after the storm has dropped heavy snow, sleet, and freezing rain from the Southern Rockies to New England through Monday. Forecasters predict low temperatures that could break several records, with wind chills plummeting to as low as -50 degrees Fahrenheit in the Northern Plains.
Getting a clear prediction of where this storm will strike hardest has been challenging for forecasters. The storm is influenced by complex factors that scientists are still trying to fully understand, primarily involving frigid Arctic air colliding with a moisture-rich weather system moving inland from the Pacific Ocean.
“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 impacts could last for a while, and since such a vast area of the U.S. will be affected, the outcomes are expected to vary widely from location to location. Lopez Lang advises people to closely monitor local forecasts, noting that even though it’s all connected to the same system, the effects can be very different.
During winter, parts of the Arctic experience months of darkness, allowing the air to become extremely cold. Typically, a strong wind current known as the jet stream prevents this cold air from affecting southern regions significantly. However, a large high-pressure system has allowed the jet stream to dip lower, letting the frigid air sweep further down into Canada and the U.S.
When the moisture-laden system from the Pacific moves inland and interacts with the jet stream, the combination of wet and cold can cause several hazards, including snow and freezing rain. Freezing rain occurs when raindrops freeze upon hitting surfaces, causing ice to accumulate on roads and infrastructure. The cold will linger after the storm, extending the risk of impacts.
The NWS forecasts significant to possibly catastrophic ice accumulations, which could lead to long power outages, extensive tree damage, and extremely dangerous travel conditions. Ice is heavy enough to bring down power lines, potentially leaving many homes without electricity or heat. The severe cold snap that hit Texas in 2021 left millions without heat when ice clogged gas pipelines.
While it’s too soon to determine climate change’s exact role in this storm, there are unique factors at play that may be linked to a changing climate. For instance, the atmosphere’s ability to hold more water vapor can result in heavier rainfalls during storms.
Additionally, the jet stream has become more erratic. Historically, the temperature difference between the tropics and the poles kept it stable, but the Arctic is warming faster than other regions. As the temperature gap lessens, the jet stream becomes less predictable, allowing colder Arctic air to push further south when it wobbles.
Interestingly, severe cold snaps like this have become less common as global temperatures rise, which presents its own challenges since communities may not be fully prepared when such events do occur, experts tell The Verge. They emphasize that climate change influences extreme weather in diverse ways, not solely through heat.
“People often wonder how global warming can coexist with extreme cold or snowfall. Climate change means not just higher baseline temperatures but also more extreme variations in both directions,” says Kaitlyn Trudeau, a senior research associate at the nonprofit Climate Central. “Assessing climate change based on a single cold storm is like evaluating a baseball season by just one inning.”
Lopez Lang is preparing for the storm’s effects in Wisconsin, both at home and at work. Weather permitting, her and her colleagues plan to fly into the storm as it moves off the east coast to study its evolution. They’ll be using a NASA aircraft to collect measurements on water vapor, temperature, and other factors that affect this event. Their aim is to examine the storm’s structure to gain a better understanding of what occurs when a weather system like this encounters the jet stream.
Understanding how the storm will progress has been challenging for forecasters due to the uncertainty surrounding the timing and nature of that interaction. “These mergers are major components of the uncertainty in forecasts,” Lopez Lang notes. “We aim to observe them closely so we can gather the best data for making accurate predictions.”
