The Polar Vortex starts to behave strangely, cooling down to record levels and going into overdrive, shaping the weather as we head for Winter finale

By: AuthorAndrej Flis

Posted onPublished: 06/02/2022

CategoriesGlobal weather

The Polar Vortex is starting to power up unusually in the late Winter Season, reaching record cold levels in the lower stratosphere. This is not without consequences, as it will strengthen the polar circulation into late winter and will be ready to continue into early Spring, influencing the weather in the United States and Europe.

The Polar Vortex is a powerful short-to-medium term weather component during the cold season. It is strongly connected all the way from the ground up into the higher levels of the atmosphere.

For this reason, we always take great notice of the activity high above in the stratosphere and monitor it all the time. In the next days, the Polar Vortex will behave a bit unusual, as it will kick into overdrive, reaching near record-high power values for this time of year.

First, we will quickly and simply learn what the Polar Vortex really is and how is it so influential. We try to explain this in most of our winter articles, as this is an important part of every winter season.

Such powerful yet simple knowledge really helps to understand the bigger picture of how the weather works in the large picture.



The Polar Vortex can be simply explained as a very large cyclonic circulation, covering the whole north pole, down to the mid-latitudes. It has a strong presence at all levels, from the ground up into the middle atmosphere, having different shapes at different altitudes.

The Polar Vortex is so large that we have to divide it into two altitude parts. One is the lower (tropospheric) part and the second is the upper (stratospheric) part. The stratospheric polar vortex plays an important role in weather development, while the lower tropospheric polar vortex actually circulates the weather that we experience.

But what is this stratosphere? Well, the atmosphere has different layers. Our weather is found in the lowest layer of the atmosphere called the troposphere. It reaches up to around 8 km (5 miles) altitude over the polar regions and up to around 15 km (9-10 miles) over the equator.

Above it, we have a much deeper layer called the stratosphere. This layer is around 30 km/18.5mi deep and is very dry. The Ozone layer resides in the stratosphere. You can see the layers of the atmosphere on the image below, with the troposphere and the weather on the bottom and the stratosphere with the ozone layer above it.


The image below shows a typical example of the upper Polar Vortex at around 30km/18.5miles altitude in the middle stratosphere during winter. It has a very nice circular shape, with the temperature dropping quickly towards its inner core.


strong Polar Vortex usually means strong polar circulation. This usually locks the cold air into the Polar regions, creating a milder winter for most of the United States and Europe.

As a contrast, a weak (wavy) Polar Vortex can bring very dynamic weather. It has a much harder time containing the cold air, which can now escape out of the polar regions, into the United States and/or Europe. Image by NOAA.



In the next image below, we have the polar vortex at a much lower altitude, around 5km/3miles. The closer to the ground we go, the more deformed the polar vortex gets because it has to interact with the mountains and overall terrain and also with the strong weather systems.


Be aware of the cold “arms” extending out of the polar vortex. They bring colder air and snowfall into the mid-latitudes. These arms pack a lot of energy and can create strong winter storms, like for example Nor’easters in the United States or very strong wind storms across the North Atlantic.

For an even better idea, we produced a high-resolution video for you, which nicely shows the Polar Vortex spinning over the Northern Hemisphere at the 30mb level, around 23km/14miles altitude.

Video shows the NASA GEOS-5 analysis for late January. Notice how the polar vortex covers a large part of the Northern Hemisphere. You can nicely see how it spins over the Northern Hemisphere, driving also the winter weather with its circulation.

Polar Vortex circulation (click to play)

   Hurricane Marie moving across the Eastern Pacific – SWE / MK

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But why (and how) does the polar vortex even form every winter season?

Every year as we head into autumn, the polar regions start to receive much less sunlight. This way, cooling begins over the north pole. But as the polar temperatures drop, the atmosphere further south is still relatively warm as it continues to receive energy from the Sun.

You can see the winter solstice on the image below when the polar regions receive little to zero solar energy, compared to regions further south.


So, as the temperature difference towards the south increases, this also means pressure changes. A large low-pressure (cyclonic) circulation starts to develop across the Northern Hemisphere from the surface layers, far up into the stratosphere. This is known as the Polar Vortex.

While the stratospheric polar vortex is spinning high above our weather, it is still directly connected to the lower levels and can shape our daily weather in many ways, driving it as one large circulation over the entire hemisphere.


When looking at the polar vortex in the stratosphere, we tend to use the 10mb level. That is around 28-32km (17-20 miles) in altitude. This layer is considered to be in the mid-stratosphere and provides a very good representation of the general strength of the stratospheric polar vortex and its downward connection.

The strength of the polar vortex is most often measured by the power of the winds that it produces. This is typically done by measuring the zonal (west to east) wind speeds around the polar circle (60°N latitude).

On the image below we have the seasonal average zonal wind speed for the Polar Vortex at 10mb level. The black line is the long-term average. Winer season last year is the red line, and the blue line is the current winter season 2021/22. The yellow area shows the daily historical min/max wind speeds. Image from


It is obvious that this season, the polar vortex is having a near-constant power increase. It was fluctuating up/down but kept a steady uptrend in power. Looking at the black “average” line, the polar vortex typically starts the seasonal weakening in mid-January.

Below we have an extended ensemble forecast for the 10mb winds. It shows the polar vortex currently being quite stronger than average. The forecast keeps it at a very strong level, reaching unusually high power for this time of year.


Looking at the pressure anomalies over the polar regions in the past three months, we can notice an interesting progression. The next image below shows pressure anomalies from the surface into the upper stratosphere.

You can observe the strong low-pressure buildup in the stratosphere in late November. That was a strong polar vortex, connecting easily down to the surface levels in early December. But strong high-pressure anomalies have emerged over the polar circle in December, which pushed back against the stratosphere, “disconnecting” the upper and the lower polar vortex.


In late January, we can see the strong buildup of low-pressure anomalies in the stratosphere. That corresponds to the high power and circulation of the stratospheric polar vortex. It is currently not fully connected down on a hemispheric level but has a more local connection.

Looking at the current polar vortex development, we can see that the vortex is in a good shape. It has a slightly oval shape, but a strong and stable wind field. There is a semi-persistent high-pressure area in the North Pacific and East Asia pressing against it, creating its oval shape.


Taking a look at the temperature profile at the 50mb level (19km/12mi), we see its cold-core over the Arctic regions and Greenland. This altitude is considered to be the lower stratosphere and is more connected to the weather circulation in the lower levels.


Texas snowstorms are due to rapid heating of the Arctic, say scientists

A warming Arctic Circle could be responsible for bursts of cold weather in the south.

STEPHEN JOHNSON18 February, 2021

Texas snowstorms are due to rapid heating of the Arctic, say scientists

Credit: Philip via Adobe Stock

  • Winter Storm Uri brought snow and freezing temperatures to Texas this week, causing multiple deaths and damage to infrastructure.
  • Climate scientists have spent years exploring the relationship between extreme winter weather and warming temperatures in the Arctic Circle.
  • Some studies suggest that the warming Arctic disrupts a natural phenomenon known as the polar vortex, which normally contains cold air in the north.

Winter Storm Uri battered the southern U.S. this week with frigid temperatures and unusually high snowfall. In Texas, the cold weather brought widespread power outages and damage to infrastructure, contributing to at least several dozen deaths.

But while the consequences of the storm are evidence, its causes are more of a mystery. In the context of climate change, the recent weather raises an obvious question: If the climate is warming, why are some parts of the world experiencing bouts of extreme cold?

It’s a topic climate scientists have been exploring for years.

One idea centers on the pattern of cold air above the Arctic Circle. This pattern, known as the polar vortex, is an area of cold, low-pressure air that swirls in the stratosphere above Earth’s North and South poles. When it’s strong, the polar vortex spins in a regular pattern, with the jet stream serving as a barrier that keeps cold air contained in the north.

But warm weather can disrupt this system. When temperatures rise, the jet stream weakens and becomes wobbly, sometimes allowing cold air to shoot out across the planet. What may be contributing to disruptions in the polar vortex is a phenomenon called Arctic amplification, which describes how the Arctic has warmed by more than twice the global average in recent decades.

Credit: NOAA/

Although some studies suggest relationships between the warming Arctic and increased winter storms, scientists still aren’t exactly sure how Arctic climate change might be reshaping winters around the world. For example, the polar vortex is a natural phenomenon, and so some of its fluctuations could be attributed to natural variability. What’s more, other factors, like changes to Arctic atmosphere and sea ice, might also play a role.

Credit: NOAA

Given the complexity of climate systems, it’s difficult for scientists to determine how changing temperatures in one region may affect weather patterns in another. But that’s not to say they’re all in complete disagreement. A 2020 paper published in Nature, for example, commented on the “divergent consensuses” between various observational and model studies on the topic of Arctic warming and severe winter weather.

“The divide on the influence of Arctic change has contributed to the impression that this research topic is controversial and lacking consensus,” the authors wrote. “An alternative interpretation is that the wide range of results should be expected, owing to the varying approaches to studying the problem and the complexity and intermittency of Arctic/midlatitude connection.”

While scientists continue to study the relationship between the Arctic and weather patterns across the globe, other climate trends are relatively clear.

The average surface temperature of the planet has risen about 2.12 degrees Fahrenheit since the late 19th century, warming at a rate nearly 10 times faster than the planet did after the Ice Age, according to NASA. And despite warmer temperatures, the NOAA reports that the U.S. was hit by nearly twice the amount of extreme winter storms during the later half of the 20th century than the first.

Polar vortex to unleash frigid Arctic blast


FEBRUARY 10, 2021 / 6:53 AM / CBS NEWS

The polar vortex has become synonymous with winter’s most brutal cold. For days, the weather system has been sitting and spinning right along the U.S.-Canada border, with temperatures as low as 43 degrees below zero in northern Minnesota. 

But now, there are signs it is about to surge south, bringing with it record-shattering cold air from the far reaches of Alaska and Northern Canada. By the weekend, temperatures in Kansas City and St. Louis will be below what’s normal for Fairbanks, Alaska.

Ahead of this Arctic blast, there will be a series of winter storms along the collision zone of cold and warm air, bringing ice from Texas to Tennessee and significant snow to Washington, D.C.

The polar vortex is a sprawling area of cold upper-level low pressure that typically resides in the Arctic. But every so often, the normal winter pattern becomes disrupted, splitting the polar vortex and sending pieces flying in different directions. One of those pieces is sitting just north of the U.S.-Canada border.

This bitter airmass landed there because of a phenomenon called a sudden stratospheric warming, a natural event that occurs 50,000 to 100,000 feet above the Arctic every couple of years, throwing weather patterns off-kilter. This event is often followed by a mountain of unusually warm air near the Arctic circle that acts to reroute pieces of the cold polar vortex southward. 


This type of pattern creates extremes all over the world. For the past couple of weeks, instead of a gradual temperature gradient around the Northern Hemisphere, there have been pockets of extreme cold intermixed with record warmth.

As a result, temperatures on Tuesday dropped to 43 degrees below zero Fahrenheit in Cotton, Minnesota, which was 133 degrees colder than the hottest temperature in the U.S. — 90 degrees — in south Florida.

In a bout of weather whiplash, the bitter cold comes on the heels of one of the top 10 warmest Januarys on record in the U.S., with the highest departures from normal right where the coldest air is now.

And the most frigid air has yet to invade the U.S. Currently, record-setting high pressure, which is associated with the coldest airmasses, is building in Alaska and western Canada. It’s so cold in Saskatchewan, Canada, that residents are pulling out the old bucket of water trick, when water instantly freezes into ice crystals when it hits the air.

This most frigid airmass will begin it’s move southward, down the east slope of the Rockies on Friday. Temperatures this Valentine’s Day weekend will be 40 to 50 degrees Fahrenheit below normal throughout the middle of the country.

From Friday through Monday, more than 100 record low readings will be in jeopardy in the heartland, with temperatures as low as 40 degrees below zero in the northern Plain States and wind chills as low as 60 below on Sunday morning.


Temperatures will drop to near zero as far south as North Texas. On Sunday, temperatures in Kansas City and St. Louis, Missouri, will not climb out of the single digits, colder than the normal high temperature of 7 degrees in Fairbanks, Alaska, this time of year.

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Extreme cold will not be the only hazard. Disturbances will ride along the frontal boundary separating bitter cold to the north and warm, moist air to the south. From Wednesday through Friday snow, ice and rain will straddle the boundary, with some areas from Dallas, Texas, to Little Rock, Arkansas, to Lexington, Kentucky, getting a glaze of treacherous ice.

Washington, D.C., will be just north of the front, and for the nation’s capital, that means mainly snow. From Wednesday afternoon through Friday morning, the area will pick up an extended period of intermittent light to moderate snowfall. In total, from West Virginia to Roanoke and Northern Virginia a general 5 to 10 inches will accumulate.


Further north in New York City, the cold-dry airmass will block the storm system, keeping it to the south. While snow showers will fly on Thursday and Friday, they will not amount to much. That is, until Sunday, when a stronger storm looks to take aim at the rest of the Northeast. If it materializes, another significant snow and ice storm may be in the cards.

The polar vortex is about to split in two. But what does that actually mean?

Philip Kiefer  1 day ago

The shirtless ‘Q Shaman’ seen storming the Capitol in face paint and a furry…Dr. Fauci Says When Your City Will Open Up AgainThe polar vortex is about to split in two. But what does that actually mean?

The polar vortex is about to split in two. But what does that actually mean? (

A blob of warm air high in the atmosphere has pushed the polar vortex off its axis over the past week. In the coming days, it’s likely to split into pieces, with possible ripple effects on weather across the northern hemisphere.a large body of water: The polar vortex might mean cold weather—but it's not clear how much snow or ice that might mean.© Provided by Popular Science The polar vortex might mean cold weather—but it’s not clear how much snow or ice that might mean.

But don’t start stocking soup for a blizzard yet; although a distorted vortex has been linked to blizzards and cold snaps before, atmospheric scientists say that it’s too soon to know which part of the world might bear the brunt.

The polar vortex is a cap of rotating air that’s usually centered on the North Pole. (There’s another vortex in the Southern Hemisphere.) It sits in the stratosphere, a high-altitude band of the atmosphere far above the wind, clouds, and precipitation we feel on the ground.a large body of water: The polar vortex might mean cold weather—but it's not clear how much snow or ice that might mean.© Jaymantri/Pexels The polar vortex might mean cold weather—but it’s not clear how much snow or ice that might mean.

As the pole goes dark and freezes in the fall, winds begin to swirl and rise from west to east to balance the temperature gap between low latitudes and the poles. The vortex formed by that wind, which turns counterclockwise around the Pole, ends up much colder than the surrounding air.

But high-altitude heat waves called “sudden stratospheric warming events” can disrupt the vortex.

That’s what’s happening now. A wobble of the jet stream (the fast-moving wave of air that circles the Pole in the atmosphere below the polar vortex, has led to extreme warming in the stratosphere, disrupting the polar vortex. “Essentially that vortex is getting shoved off the Pole and into the mid-Atlantic,” says IBM meteorologist Michael Ventrice.diagram: We've only begun to really understand the polar vortex relatively recently.© NOAA We’ve only begun to really understand the polar vortex relatively recently.

It’s not especially unusual for the vortex to break down. Although this one is particularly powerful, “stratospheric warming events happen about every other year,” says Andrea Lopez Lang, an atmospheric scientist at the University at Albany.

Over the past week, a high-pressure ridge of air has sat in the lower atmosphere around Siberia. As the jet stream runs into that ridge, explains Lopez Lang, it directs waves of energy upwards towards the stratosphere.

“Think about ocean waves on a beach,” Amy Butler, a research scientist at NOAA Chemical Sciences Laboratory, wrote in an email. “when they crash on the shore, the energy from those waves is dissipated through friction with the beach surface. In the atmosphere, waves can also break, but in this case the energy from those waves slows the polar vortex and heats the stratosphere.”

That disruption caused the vortex to slow down and spread outwards. Now, Ventrice says, the vortex appears to be on a path to splitting, “where we have essentially two areas of a vortex.”diagram: We've only begun to really understand the polar vortex relatively recently.© Provided by Popular Science We’ve only begun to really understand the polar vortex relatively recently.

But it’s hard to predict what the exact on-the-ground consequences might be. “This field of research is still in its infancy,” Ventrice says. “We’re just understanding now that these splits are important for prediction of [weather patterns] going out weeks.”

“I think there’s going to be a spectrum of splits,” he says. Slightly different divisions could have different impacts on the weather, in ways that aren’t entirely understood, he says. “I’ve seen years where three vortices split out.”

This year, he thinks there will be “a little piece of the vortex that splits off and spins away.”

A 2018 paper published in the Bulletin of the American Meteorological Society found that weaker and more distorted polar vortices were linked to bursts of freezing weather, but that the physical connection between the two was still unclear.

It’s not that the splitting vortex itself will touch down and cause cold weather (although that’s possible), but that it’s likely to cause changes to the jet stream that could in turn divert low-altitude Arctic air southward.

For most of the winter, says Ventrice, the jet stream has stayed to the north of the continental US. “That typically strangles all the Arctic air supply,” he says. But the breakdown of the vortex could change the shape of the jet stream below and end the pattern of mild weather.

“We’re starting to see some hints in our weather prediction models that there could be a pretty big shift in the North Pacific… that typically results in more of a connection with the Arctic Circle where cold arctic air can come down into North America”

Something similar happened in the winter of 2014, when the vortex collapsed across the Upper Midwest and much of East Asia, followed by record snowfalls and cold weather across the central and eastern United States.

To confuse the matter, since then, almost any slowdown or shift in the jet stream that leads to freezing air in the continental US has been called a “polar vortex” in the media. In reality, the term refers more narrowly to situations where the high-altitude winds slow down, with a more complicated impact on the weather.

It will take several weeks for the effects from the vortex to become clear on the surface. But once they’re there, they’ll likely be persistent.

“Most people think, why do we care what’s going on in the stratosphere? It’s 10 miles above us,” says Lopez Lang. “The reason we care is, when we disrupt this part of the atmosphere, it takes a really long time for it to recover. It can have impacts for up to two months for the lowest part of the stratosphere to get back to normal.”

The implications for larger climate trends are also unclear. There is still a debate over how a warming Arctic will impact the jet stream, which some researchers argue may slow down and become “wavier” as the planet warms. “The polar vortex is often considered a part of that mechanism,” Butler wrote in her email. The 2018 paper that found a link between weaker vortices and severe winter weather, for example, suggested that Arctic warming could be disrupting the vortex by making high-pressure zones over Siberia more likely. “The problem is that climate models completely disagree as to whether the polar vortex strengthens or weakens in the future.”

Still, she explained, understanding the link will be important for predicting winters of the future. And that doesn’t necessarily mean more storms. “If the polar vortex strengthens, for example, we could see more winter heat extremes, which would amplify the warming by increased greenhouse gases.”

Note: this article has been revised to correct an inaccuracy about the jet stream. It previously implied that the jet stream itself goes up into the stratosphere, when in fact the wave energy from the jet is what goes upward.

The polar vortex may be on its way

By Allison Chinchar, CNN meteorologist  17 hrs ago

The polar vortex may be on its wayThe polar vortex may be on its way (

The polar vortex appears to be on the move. That’s because stratospheric warming is occurring at high altitudes above the North Pole, resulting in a spike in© CNN weather

That, in turn, could result in bitter cold air pushing southward into the United States within a couple of weeks, though where exactly that Arctic air will swoop down — and for how long — remains uncertain.

The polar vortex is simply a low pressure system that swirls cold air around the polar regions of the globe. But the system can sometimes move off the North Pole. In doing so, it releases cold air much farther south in regions such as North America and Forecast temperatures for January 16, 2021© CNN weather Forecast temperatures for January 16, 2021

The polar vortex is located in the stratosphere, about 18 miles above Earth’s surface, which is well above the jet stream, where planes fly, and where most weather occurs.

But agitations and disruptions to the flow and location of the polar vortex, like what we are seeing to the start of 2021, can influence the movement of air and weather below it. And scientists are closely watching current events for clues as to when and where the impacts will occur.diagram© from NOAA

What is the polar vortex?

Although the term “polar vortex” has become trendy on social media in recent years, the concept is not new. It is a staple for the polar regions every year.

“Some winters, it remains fairly unperturbed. Other winters (like this one), it can be severely disrupted/weakened,” Jason Furtado, an assistant professor at the University of Oklahoma’s School of Meteorology, said via email. “Understanding what is happening with the polar vortex is one of several features in our climate that helps meteorologists understand what to expect for winter weather over the next 2-6 weeks.”

When the polar low pressure system is strong, it keeps the jet stream traveling around Earth in a very circular path and keeps Arctic air bundled up close to the Pole. But when that system is weakened, parts of the vortex break off and become elongated, resulting in cold air shifting southward.

When that low pressure system is weaker, the jet stream also does not have enough strength to maintain its usual path. It is that disruption in the jet stream that has a direct correlation to our weather closer to the surface.

“When the stratospheric polar vortex is strong, the jet stream tends to move further north, which keeps the cold air in the Arctic and allows relatively milder conditions across much of the United States and Eurasia,” Furtado said.

A common reason the polar vortex leaves its usual location is due to a sudden shift of hotter air, known as a sudden stratospheric warming, or SSW. This weakens the polar vortex and allows it to move.

“When the polar vortex is weak, or an SSW event occurs, then the jet stream will tend to weakened, move further south, and become ‘wavier,'” Furtado said. “The effect of these changes is for warmer than normal air to move into the Arctic, colder weather to enter North America and Europe/Asia, and more extreme weather and storms overall in the middle latitudes (e.g., snowstorms).”

Impact on the US

The jet stream is the main storm track across the middle latitudes of the Northern Hemisphere and divides colder air to the north and warmer air to the south.

Because the polar vortex is disconnected physically from where most weather occurs, it often has more of an indirect impact on daily weather.

Cold air is more dense, so it sinks, allowing the hot air from the SSW to remain in the stratosphere and the colder air to sink down into the lower levels near the surface. That downward sinking air results in sections of the polar vortex pushing down into lower latitudes of North America, Europe, and Asia.

Recently, a SSW caused the polar vortex to begin shifting away from the North Pole. But where that cold air will end up over the next week or two remains a question. What makes this SSW so special is its intensity, which increases the chances of impacting the Northern Hemisphere.

It’s important to note that a disruption in the polar vortex does not garner immediate changes to weather. Instead, its effects are typically delayed.

“In the stratosphere, the polar vortex typically recovers in strength within a couple of weeks of the peak of the event,” Furtado said. “However, in the troposphere, the effects of the SSW event (e.g., a further south jet stream, cold and stormy weather) can last for up to 8 weeks. So, these events, which can evolve quickly, can have lasting impacts on the winter weather patterns in the troposphere.”

Another thing to note: Even with strong SSW events, there is still no certainty that the US will see direct impacts.

“We actually had two events in the recent past that shows this contrast. There was a major SSW event in February 2018 and one in January 2019, and the after effects of each were very different,” Furtado said.

Furtado says we had cold and stormy weather for much of the central and eastern regions of North America following the 2018 event, but minimal effects were felt in North America following the 2019 event.

So, no need to panic about this recent event. But it’s certainly something to watch over the next seven to 14 days.

How climate change plays a role

If you have a warming Earth, then it would only make sense for more frequent sudden stratospheric warming events to occur, right? The answer is complex, mostly because no one lives at the North Pole — other than Santa — which makes long term historical weather data very hard to come by.

But this doesn’t mean climate change isn’t impacting the polar vortex.

“We know from observations that the Arctic region is warming at a much faster rate than other parts of the globe (we call this Arctic Amplification),” Furtado said. “The impact of Arctic Amplification is twofold. First, since the Arctic is getting much warmer, when cold air outbreaks occur in North America and Europe/Asia, they aren’t as cold as they were decades ago. The second effect (though currently debated in the science community) is that a warmer Arctic is also making the stratospheric polar vortex weaker on the average.”

This is why, in theory, a weaker polar vortex should be easier to disrupt, allowing for more frequent SSW events.

The takeaway? Even though a warming planet may mean the overall number of snowstorms across the globe may decrease, the ones that do happen could produce much larger snowfall accumulations.

The polar vortex may be on its way (

Polar vortex whips millions of Americans with strong winds, record lows and even snow

(CNN)More than 100 million Americans will see temperatures drop below freezing this weekend, a harsh contrast to last week’s sunny weather.

Saturday started with a tied record for the latest snowfall in New York City’s Central Park, with light snow reported by the National Weather Service.
The NWS tweeted: “Snow in Central Park! In May! The Central Park Automated Surface Observing System (ASOS) recorded snow. This ties the record latest snow set on this day in 1977.”
Central Park on Saturday morning also hit a daily record low of 34 degrees Fahrenheit.
The white stuff also fell overnight in Pennsylvania and upstate New York, and continued Saturday in Vermont, New Hampshire, Massachusetts and Maine. Shaftsbury, Vermont, got 9 inches, the National Oceanic and Atmospheric Administration reported.
At least 20 states were under a frost or freeze watch, warning or advisory on Saturday morning. Although most of those states are in the Midwest or Northeast, the advisories stretch all the way down to Georgia and South Carolina.

In some Northeast states, it felt more like early March than May. A system that began in the Great Lakes region was set to bring gusty winds and 6 to 12 inches of wet snow to New England.
“It appears that interior New England will see significant amounts of wet snow with northerly winds becoming increasingly strong and gusty late Friday night into Saturday morning,” the Weather Prediction Center said.
For cities like New York, Albany and Hartford, cold rain will be the main focus, but some snow could mix in.

Blame the polar vortex

More than 40 cities across the Midwest and Northeast set daily low temperature records Saturday morning, including Pittsburgh at 28 degrees and Baltimore at 34.
For Fort Wayne, Indiana, it was also the coldest temperature ever recorded so late in the season and the coldest temperature recorded in May, in addition to a daily record low (23 degrees).
The polar vortex was so strong this winter and spring that it led to the largest-ever Arctic ozone hole, but not a lot of cold weather.
The polar vortex, as its scary name suggests, is a circulation of strong, upper-level winds that normally surround the northern pole, moving in a west to east direction — a polar low-pressure system.
These winds tend to keep the bitter cold air locked in the Arctic regions of the Northern Hemisphere. On occasion, the vortex can become distorted and dip further south, allowing cold air to spill southward.
But it didn’t spill out into the US this winter. That’s why the spring and winter have been mild and major East Coast cities saw low snowfall amounts.
Now the polar vortex is weakening, allowing Arctic air to spill out — leading to plunging temperatures in the East this weekend.

The Polar Vortex Is Climate Disruption in Action

At least 20 people have died and vast swaths of the US Midwest and Northeast have come to a standstill because of a frigid blast of sub-zero temperatures. Another Arctic vortex has struck.

polar vortex is a large expanse of swirling, cold air that is usually located in the polar regions. However, during winter, and now more frequently due to human-caused climate disruption, the vortex expands and moves southward, bringing the Arctic temperatures with it.

Studies have shown that a warming Arctic is shifting the jet stream, and playing a critical role in the changes that are causing the polar vortex to become more common in the US.

In addition to deaths, the record low temperatures have resulted in many frostbite patients flocking to hospitals, the grounding of more than 1,600 flights in the Chicago area alone, and the US Postal Service ceasing mail delivery at times in certain areas.

Parts of the Midwest saw temperatures plummet to minus 37 degrees Fahrenheit, while Boston saw minus 5 degrees Fahrenheit. Areas of Northern Illinois saw temperatures of minus 57 with the wind chill.

There were times when temperatures in areas of the Midwest were lowerthan they were in Antarctica.

Strained Infrastructure

As human-caused climate disruption continues to worsen, extreme weather events such as this will continue to place, increasing demands on infrastructure.

For example, one utility company realized it was in danger of being unable to keep pace with the demand for natural gas, given the spike in need for heating in Michigan. After the company made an emergency appeal for everyone to conserve gas during the deep freeze, General Motors suspended operations at 11 of its plants in that state.

Homeless shelters in Lansing, Michigan, were overcrowded, and churches had to step in to assist, as did various city departments.

The Depths of Denial

On January 28, President Trump tweeted:

Donald J. Trump


In the beautiful Midwest, windchill temperatures are reaching minus 60 degrees, the coldest ever recorded. In coming days, expected to get even colder. People can’t last outside even for minutes. What the hell is going on with Global Waming? Please come back fast, we need you!

187K people are talking about this

In response, the US National Oceanic and Atmospheric Administration (NOAA) tweeted:



Winter storms don’t prove that global warming isn’t happening. 

17.2K people are talking about this

NOAA’s tweet included a link to an article that suggested severe snowstorms may well become more likely as the planet continues to warm.

Polar vortex death toll rises to 21 as US cold snap continues

Chicago skyline with lake frozenImage copyrightGETTY IMAGES
Image captionChicago’s frozen shoreline

At least 21 people have died in one of the worst cold snaps to hit the US Midwest in decades.

Ninety million people – a third of the US – have seen temperatures of -17C (0F) or below. Some 250 million Americans overall have experienced the “polar vortex” conditions.

Hospitals have been treating patients reporting frostbite as parts of the country ground to a halt.

Temperatures are expected to swing to above average over the weekend.

Who are the victims?

Homeless people have been particularly at risk, with warming shelters set up across cities.

But some still braved the freezing conditions and one woman, aged 60, was found dead in an abandoned house in Lorain, Ohio.

A hospital in Chicago has already treated 50 patients for frostbite, and some may end up losing a limb, CNN reports. Half of those patients were homeless individuals , while others had jobs that required them to be outdoors.

Some people were found dead a short walk from their homes:

  • A Michigan man who froze to death in his neighbourhood had been “inadequately dressed for the weather”, officials said
  • In a wind chill of -46C (-51F) an 18-year-old student was found unresponsive a short walk from his dorm on Wednesday and later died in hospital
  • On Tuesday, a man froze to death in a garage in Milwaukee, Wisconsin, having “apparently collapsed after shovelling snow”, according to a medical examiner

Dangerous roads have also been a factor in the deaths. A man was fatally struck by a snow plough near Chicago on Monday and in northern Indiana, a 22-year-old police officer and his wife died after a collision on icy roads.

Media captionSo what actually is a polar vortex…?

What’s the forecast?

The icy cold is expected to loosen its grip on Friday.

By the end of the weekend, Chicago could see temperatures as high as 10C (50F).

“It’s going to be at least a 60-degree swing for Chicago,” David Hamrick, a National Weather Service forecaster, told Reuters news agency.


The sudden weather change coming this weekend may be the fastest warm-up on record, meteorologists say.

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But as the temperatures abruptly turn warmer, US emergency officials warn of flooding and utility risks.

Pipes can burst with such temperature fluctuations, and rapidly melting snow and ice could cause flooding, the Federal Emergency Management Agency cautioned.

How cold did it get?

More than 30 record lows were broken across the Midwest.

Cotton, Minnesota, was the coldest place in the US on Thursday with a low of -48C (-56F) based on preliminary data.

Chicago passed the record low for 31 January, while Mount Carroll has probably beaten the Illinois record with a morning temperature of -39C (-38F).

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Media captionChicago is using fire to melt snow on the railway and keep the trains running

Cities across Iowa have also broken temperature records.

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The chill drifted eastward on Thursday, bringing sub-zero temperatures to north-eastern cities such as Boston.

Media captionMuch of Chicago River has frozen over

With wind chill factored in, temperatures of -40C (-40F) in the Midwest and Great Lakes have felt closer to -53C (-63F), which is enough to cause frostbite in less than five minutes.

Snow plough in Buffalo, New YorkImage copyrightREUTERS
Image captionSnow plough in Buffalo, New York

How is the cold snap affecting daily life?

The Arctic weather could cost the US billions of dollars. In 2014, a similar polar freeze cost the country an estimated $5bn (£3.8bn), CBS News reports.

In Minnesota and Michigan, residents were asked by gas companies to turn down their home thermostats to help handle heating demands.

Consumers Energy, a natural gas provider in Michigan, had a fire on Wednesday morning that damaged equipment and temporarily affected how much gas could be sent out to customers.

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Native American tribes in the northern Midwest states helped their members obtain heating supplies as many live in poor-quality housing, the Associated Press reports.

Andrea Cusack, a pharmacist in Michigan, began using her snowmobile to deliver essential prescriptions to snowed-in residents, according to the Lansing State Journal.

More than 2,300 flights have been cancelled and another 3,500 delayed due to the polar vortex.

Social media has been full of photos and memes showcasing just how shockingly cold the Midwest became.

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End of Facebook post by Tom Skilling