How the polar vortex and warm ocean intensified a major US winter storm

Mathew Barlow, UMass Lowell and Judah Cohen, Massachusetts Institute of Technology (MIT)

A severe winter storm that brought crippling freezing rain, sleet and snow to a large part of the U.S. in late January 2026 left a mess in states from New Mexico to New England. Hundreds of thousands of people lost power across the South as ice pulled down tree branches and power lines, more than a foot of snow fell in parts of the Midwest and Northeast, and many states faced bitter cold that was expected to linger for days.

The sudden blast may have come as a shock to many Americans after a mostly mild start to winter, but that warmth may have partly contributed to the ferocity of the storm.

As atmospheric and climate scientists, we conduct research that aims to improve understanding of extreme weather, including what makes it more or less likely to occur and how climate change might or might not play a role.

To understand what Americans are experiencing with this winter blast, we need to look more than 20 miles above the surface of Earth, to the stratospheric polar vortex.

What creates a severe winter storm like this?

Multiple weather factors have to come together to produce such a large and severe storm.

Winter storms typically develop where there are sharp temperature contrasts near the surface and a southward dip in the jet stream, the narrow band of fast-moving air that steers weather systems. If there is a substantial source of moisture, the storms can produce heavy rain or snow.

In late January, a strong Arctic air mass from the north was creating the temperature contrast with warmer air from the south. Multiple disturbances within the jet stream were acting together to create favorable conditions for precipitation, and the storm system was able to pull moisture from the very warm Gulf of Mexico.

Where does the polar vortex come in?

The fastest winds of the jet stream occur just below the top of the troposphere, which is the lowest level of the atmosphere and ends about seven miles above Earth’s surface. Weather systems are capped at the top of the troposphere, because the atmosphere above it becomes very stable.

The stratosphere is the next layer up, from about seven miles to about 30 miles. While the stratosphere extends high above weather systems, it can still interact with them through atmospheric waves that move up and down in the atmosphere. These waves are similar to the waves in the jet stream that cause it to dip southward, but they move vertically instead of horizontally.

You’ve probably heard the term “polar vortex” used when an area of cold Arctic air moves far enough southward to influence the United States. That term describes air circulating around the pole, but it can refer to two different circulations, one in the troposphere and one in the stratosphere.

The Northern Hemisphere stratospheric polar vortex is a belt of fast-moving air circulating around the North Pole. It is like a second jet stream, high above the one you may be familiar with from weather graphics, and usually less wavy and closer to the pole.

Sometimes the stratospheric polar vortex can stretch southward over the United States. When that happens, it creates ideal conditions for the up-and-down movement of waves that connect the stratosphere with severe winter weather at the surface.

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The forecast for the January storm showed a close overlap between the southward stretch of the stratospheric polar vortex and the jet stream over the U.S., indicating perfect conditions for cold and snow.

The biggest swings in the jet stream are associated with the most energy. Under the right conditions, that energy can bounce off the polar vortex back down into the troposphere, exaggerating the north-south swings of the jet stream across North America and making severe winter weather more likely.

This is what was happening in late January 2026 in the central and eastern U.S.

If the climate is warming, why are we still getting severe winter storms?

Earth is unequivocally warming as human activities release greenhouse gas emissions that trap heat in the atmosphere, and snow amounts are decreasing overall. But that does not mean severe winter weather will never happen again.

Some research suggests that even in a warming environment, cold events, while occurring less frequently, may still remain relatively severe in some locations.

One factor may be increasing disruptions to the stratospheric polar vortex, which appear to be linked to the rapid warming of the Arctic with climate change.

Additionally, a warmer ocean leads to more evaporation, and because a warmer atmosphere can hold more moisture, that means more moisture is available for storms. The process of moisture condensing into rain or snow produces energy for storms as well. However, warming can also reduce the strength of storms by reducing temperature contrasts.

The opposing effects make it complicated to assess the potential change to average storm strength. However, intense events do not necessarily change in the same way as average events. On balance, it appears that the most intense winter storms may be becoming more intense.

A warmer environment also increases the likelihood that precipitation that would have fallen as snow in previous winters may now be more likely to fall as sleet and freezing rain.

There are still many questions

Scientists are constantly improving the ability to predict and respond to these severe weather events, but there are many questions still to answer.

Much of the data and research in the field relies on a foundation of work by federal employees, including government labs like the National Center for Atmospheric Research, known as NCAR, which has been targeted by the Trump administration for funding cuts. These scientists help develop the crucial models, measuring instruments and data that scientists and forecasters everywhere depend on.

This article, originally published Jan. 24, 2026, has been updated with details from the weekend storm.

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Mathew Barlow, Professor of Climate Science, UMass Lowell and Judah Cohen, Climate scientist, Massachusetts Institute of Technology (MIT)

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The science section of our news blog STM Daily News provides readers with captivating and up-to-date information on the latest scientific discoveries, breakthroughs, and innovations across various fields. We offer engaging and accessible content, ensuring that readers with different levels of scientific knowledge can stay informed. Whether it’s exploring advancements in medicine, astronomy, technology, or environmental sciences, our science section strives to shed light on the intriguing world of scientific exploration and its profound impact on our daily lives. From thought-provoking articles to informative interviews with experts in the field, STM Daily News Science offers a harmonious blend of factual reporting, analysis, and exploration, making it a go-to source for science enthusiasts and curious minds alike. https://stmdailynews.com/category/science/

Geoff Childs, Washington University in St. Louis

Dorje Dundul recently had his foot gnawed by a brown bear – a member of the species Ursus thibetanus, to be precise.

It wasn’t his first such encounter. Recounting the first of three such violent experiences over the past five years, Dorje told our research team: “My wife came home one evening and reported that a bear had eaten a lot of corn from the maize field behind our house. So, we decided to shoo it away. While my wife was setting up camp, I went to see how much the bear had eaten. The bear was just sitting there; it attacked me.”

Dorje dropped to the ground, but the bear ripped open his shirt and tore at his shoulder. “I started shouting and the bear ran away. My wife came, thinking I was messing with her, but when she saw the wounds, she knew what had happened.”

Researchers Dolma Choekyi Lama, Tsering Tinley and I spoke with Dorje – a 71-year-old resident of Nubri, a Buddhist enclave in the Nepalese highlands – as part of a three-year study of aging and migration.

Now, you may be forgiven for asking what a bear attack on a septuagenarian has to do with demographic change in Nepal. The answer, however, is everything.

In recent years, people across Nepal have witnessed an increase in bear attacks, a phenomenon recorded in news reports and academic studies.

Inhabitants of Nubri are at the forefront of this trend – and one of the main reasons is outmigration. People, especially young people, are leaving for education and employment opportunities elsewhere. It is depleting household labor forces, so much so that over 75% of those who were born in the valley and are now ages 5 to 19 have left and now live outside of Nubri.

It means that many older people, like Dorje and his wife, Tsewang, are left alone in their homes. Two of their daughters live abroad and one is in the capital, Kathmandu. Their only son runs a trekking lodge in another village.

Scarcity of ‘scarebears’

Until recently, when the corn was ripening, parents dispatched young people to the fields to light bonfires and bang pots all night to ward off bears. The lack of young people acting as deterrents, alongside the abandonment of outlying fields, is tempting bears to forage closer to human residences.

Outmigration in Nubri and similar villages is due in large part to a lack of educational and employment opportunities. The problems caused by the removal of younger people have been exacerbated by two other factors driving a rapidly aging population: People are living longer due to improvements in health care and sanitation; and fertility has declined since the early 2000s, from more than six to less than three births per woman.

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These demographic forces have been accelerating population aging for some time, as illustrated by the population pyramid constructed from our 2012 household surveys in Nubri and neighboring Tsum.

A not-so-big surprise, anymore

Nepal is not alone in this phenomenon; similar dynamics are at play elsewhere in Asia. The New York Times reported in November 2025 that bear attacks are on the rise in Japan, too, partly driven by demographic trends. Farms there used to serve as a buffer zone, shielding urban residents from ursine intruders. However, rural depopulation is allowing bears to encroach on more densely populated areas, bringing safety concerns in conflict with conservation efforts.

Dorje can attest to those concerns. When we met him in 2023 he showed us deep claw marks running down his shoulder and arm, and he vowed to refrain from chasing away bears at night.

So in October 2025, Dorje and Tsewang harvested a field before marauding bears could get to it and hauled the corn to their courtyard for safekeeping. The courtyard is surrounded by stone walls piled high with firewood – not a fail-safe barrier but at least a deterrent. They covered the corn with a plastic tarp, and for extra measure Dorje decided to sleep on the veranda.

He described what happened next:

“I woke to a noise that sounded like ‘sharak, sharak.’ I thought it must be a bear rummaging under the plastic. Before I could do anything, the bear came up the stairs. When I shouted, it got frightened, roared and yanked at my mattress. Suddenly my foot was being pulled and I felt pain.”

Dorje suffered deep lacerations to his foot. Trained in traditional Tibetan medicine, he staunched the bleeding using, ironically, a tonic that contained bear liver.

Yet his life was still in danger due to the risk of infection. It took three days and an enormous expense by village standards – equivalent to roughly US$2,000 – before they could charter a helicopter to Kathmandu for further medical attention.

And Dorje is not the only victim. An elderly woman from another village bumped into a bear during a nocturnal excursion to her outhouse. It left her with a horrific slash from forehead to chin – and her son scrambling to find funds for her evacuation and treatment.

So how should Nepal’s highlanders respond to the increase in bear attacks?

Dorje explained that in the past they set lethal traps when bear encroachments became too dangerous. That option vanished with the creation of Manaslu Conservation Area Project, or MCAP, in the 1990s, a federal initiative to manage natural resources that strictly prohibits the killing of wild animals.

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Learning to grin and bear it?

Dorje reasons that if MCAP temporarily relaxed the regulation, villagers could band together to cull the more hostile bears. He informed us that MCAP officials will hear nothing of that option, yet their solutions, such as solar-powered electric fencing, haven’t worked.

Dorje is reflective about the options he faces as young people leave the village, leaving older folk to battle the bears alone.

“At first, I felt that we should kill the bear. But the other side of my heart says, perhaps I did bad deeds in my past life, which is why the bear bit me. The bear came to eat corn, not to attack me. Killing it would just be another sinful act, creating a new cycle of cause and effect. So, why get angry about it?”

It remains to be seen how Nubri’s residents will respond to the mounting threats bears pose to their lives and livelihoods. But one thing is clear: For those who remain behind, the outmigration of younger residents is making the perils more imminent and the solutions more challenging.

Dolma Choekyi Lama and Tsering Tinley made significant contributions to this article. Both are research team members on the author’s project on population in an age of migration.

Geoff Childs, Professor of Sociocultural Anthropology, Washington University in St. Louis

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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In our continuing look at how entertainment—television, movies, and streaming shows—grapples with real-world issues, this time we turn our attention to gentrification and the often-repeated call to “shop local.” Once again, we examine how popular culture frames these conversations, this time through the CBS sitcom The Neighborhood and the episode “Welcome Back to What Used to Be the Neighborhood.”

A Familiar Story: When the Neighborhood Changes

In the episode, Calvin’s favorite longtime restaurant closes its doors and is replaced by a flashy new pet spa. To Calvin, the change symbolizes something much bigger than a single business closing—it represents the slow erosion of the neighborhood he knows and loves. In response, he launches a campaign urging friends and neighbors to buy local in order to protect small businesses from disappearing.

Emotionally, the episode hits home. Many communities across the country have watched beloved neighborhood institutions vanish, replaced by businesses that feel disconnected from the area’s history and culture. In that sense, The Neighborhood gets something very right: gentrification often shows up one storefront at a time.

Where Television Simplifies a Complicated Reality

But, as is often the case with television, the episode also simplifies a much more complex economic reality.

The show frames “shopping local” as a direct alternative to shopping online, subtly suggesting that online platforms are inherently harmful to small businesses. In real life, however, the line between “local” and “online” is no longer so clear.

Many local and small businesses now survive precisely because they sell online—through their own websites, through Amazon, or through other platforms that support independent sellers. For some, online sales are not a threat to local commerce; they are a lifeline.

Why Brick-and-Mortar Isn’t Always Sustainable

Rising costs are a major factor driving these changes. Commercial leases, insurance premiums, utilities, staffing costs, and local fees have all increased dramatically in many cities. For small business owners, keeping a physical storefront open can become financially impossible—even when customer support remains strong.

As a result, some businesses choose to close their brick-and-mortar locations while continuing to operate online. Others scale back to pop-ups, shared spaces, or hybrid models. These businesses may no longer have a traditional storefront, but they are still local—employing local workers, paying local taxes, and serving their communities in new ways.

The Real Issue Behind “Shop Local”

Where The Neighborhood succeeds is in capturing the emotional truth of gentrification: the sense of loss, displacement, and cultural change that comes with rising rents and shifting demographics.

Where it misses the mark is in suggesting that consumer choices alone—simply avoiding online shopping—can solve the problem.

The real challenges facing local and small businesses go far beyond individual buying habits. They include zoning policies, commercial rent practices, corporate consolidation, and economic systems that increasingly favor scale over community presence.

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A Conversation Worth Having—Even If TV Can’t Finish It

The Neighborhood deserves credit for bringing these issues into mainstream conversation. It sparks discussion, even if it wraps a complicated topic in a sitcom-friendly moral lesson.

The reality is messier. Supporting local businesses today often means rethinking what “local” looks like in a digital economy—and recognizing that survival sometimes requires adaptation, not nostalgia.

Further Reading & External Resources

• U.S. Small Business Administration: Marketing & Online Sales for Small Businesses
  Explains how small businesses use websites, marketplaces, and digital tools to survive and grow.
• Brookings Institution: Understanding Gentrification
  A research-based overview of gentrification, its causes, and its impact on local communities.
• National Main Street Center: Supporting Local Small Businesses
  Resources focused on preserving local businesses while adapting to economic change.
• SCORE: Why Going Online Is Critical for Small Business Survival
  Mentorship-backed guidance on how digital sales help small businesses remain competitive.
• Harvard Business Review: How Small Businesses Can Compete in an Online Economy
  An analysis of how independent businesses adapt to large online platforms without losing identity.

At STM Daily News, our Local and Small Business coverage continues to explore these real-world dynamics beyond the TV screen, highlighting the challenges, innovations, and resilience of the businesses that keep communities alive—whether their doors are on Main Street or their storefronts live online.

📍 Read more Local and Small Business coverage at: STM Daily News