Polar Vortex Is Back In The News. Don't Panic, But It Could Cause Something Called "Winter"

Schematic of how something called Sudden Stratospheric Warming
can split up the Polar Vortex and send those cold pieces closer
to Europe and the United States, increasing the risk
of harsh winter weather. 

Some of you might remember the media hype back in the winters of 2014 and 2015 about the "Polar Vortex."

At the time it was hyped as some new-fangled thing unleashing supposedly apocalyptic winter despair on the nation, or something like that.  

Well, the hype is back, at least sort of. The polar vortex, or at least a particular orientation of it threatens us again. It could cause us to experience something called "winter."

The short version of this things are changing in the atmosphere, as they often do in the winter, in a way that could bring some sharp cold spells and maybe some good sized snowstorms to parts of the middle and eastern parts of the United States.

Let's explain: As non-insane people explained in the winter of 2014, the polar vortex is something that's totally, absolutely normal.  It's pretty much always there, spinning high overhead in the Arctic.

It's basically a circle of strong winds spinning around  a blob of particularly cold air up north.

Sometimes the polar vortex moves a little south, sometimes toward Europe, sometimes down into central or eastern Canada. When that happens, the cold air on the ground moves south, too.

If the polar vortex approaches Europe, it gets really cold there. If the polar vortex gets south into Canada, chances are there will be some subzero cold in the United States. Plus, depending upon how the polar vortex orients itself, some areas get decent snowstorms.

Now, I'm going to introduce another so-called villain that is getting a lot of hype this particular winter. 

It's called Sudden Stratospheric Warming. Again, it sounds terribly frightening to most people, because they've never heard of it before and it sounds like something has gone off the rails.

Well, no. Sometimes, very high in the atmosphere over the Arctic, above where most weather systems live, the air quickly gets unusually warm. Again, scientists have long known about this, and it's not like the world is going to end in 15 minutes.

Weather geeks have been going bananas since at least early December over this winter's Sudden Stratosphere Warming when forecasts first indicated it might happen and then it unfolded. Until now, I've spared you this esoteric excitement because it had absolutely zero effect on your life.

But now it looks like we're approaching the time when you might, just might, feel the effects of this thing, which we'll call SSW for short. Trust me, you're not going die.

In the weeks after an SSW develops, its effects begin to trickle down to near the Earth's surface and begins to affect the weather we experience.

The SSW very often moves the polar vortex southward, or splits it up into two or three mini-polar vortexes. That's what is happening this winter. It looks like the Northern Hemisphere is temporarily home to three of these mini-polar, um, vortexes? vortices?  

These little baby vortices  also drift south, opening the door for Arctic outbreaks to hit the mid-latitudes. That's why central and parts of southern Europe have experienced so much snow and cold over the past couple of weeks.

Another "mini polar vortex" of sorts seems to be setting up in Canada. Though this is not definite, it looks likely that this might set the eastern and central United States up for some Arctic cold for the end of January and into February.

We might already be starting to see the effects of all this. We managed to get a typical cold wave on us this weekend, and another brief one will be upon us around Thursday. Things look like they will become more active and stormy within about a week or so, but nobody yet has any idea how stormy.

Long range forecasts after that indicate repeated influxes of Arctic air and a risk of some snowstorms through the beginning of February.  This somewhat more exciting weather pattern should be established within a week here in the Northeast.

There's no telling how extreme things will get. Yes, it'll be winter. So you have to expect these spells  of Arctic cold and snowy weather.  There's also a chance that other atmospheric conditions, like a strong west-to-east jet stream coming across the Pacific Ocean into North America, could thwart many of the invasions of Arctic air from the North Pole.

On some occasions, the weather following a SSW can get awfully extreme, worse than your standard winter conditions.

That was the case in 2015, when Boston had an unprecedented snow siege. The city had 94 inches of snow in just 30 days in late January and February that year. February, 2015 in Burlington, Vermont was the third coldest on record.  I've gotten wimpy in my old age, so I'm hoping we don't get a repeat of 2015.

Last year, harsh weather after an SSW blasted much of Europe, and contributed to frigid, snowy conditions in much of the United States through March. That snowy chill lingered well into April, especially in the northern and central Plains.

If the current aftermath of a SSW brings cold, snowy weather to New England or elsewhere in the United States, it's really not possible right now to tell how long it would last or how intense it will get.  It could be just a couple weeks of rough weather. Or, worse case scenario, a couple months.

Scientists are investigating whether SSW's would become more frequent because of climate change. Some preliminary evidence suggests this is the case. Which would bring many of us in Europe and the eastern half of the United States a strange irony:

Conditions would warm up as years and decades go by, but we'd still be at risk of occasionally getting some of the harshest possible long spells of Arctic winter weather.