Polar Vortex Blog

“It could be … it might be … it…!” Wait, is it? A homerun for the stratosphere? After a brief respite, the stratospheric polar vortex is expected to weaken again with potentially another major sudden stratospheric warming forecast to occur in the next week. But didn’t we just have a sudden stratospheric warming event?? Read on to find out what’s in the stratosphere’s line-up and how this double header fits in with typical stratosphere behavior. Loading the atmospheric bases  The atmospheric players have been positioning themselves again for another polar vortex disruption. First up, the current stratospheric conditions are primed for tropospheric wave activity because the polar vo…   Read article

With the occurrence of a major disruption to the polar vortex (or sudden stratospheric warming) on January 16 2023 [footnote 1], one of the first questions everyone asks is “How can a disruption way up in the Arctic stratosphere affect the winds and weather far below in the troposphere?”. A stratospheric traffic accident Scientists have a pretty good understanding of how a reversal of the winds ~19 miles above the Arctic influences the winds at lower altitudes, at least down to about the tropopause (the altitude where the troposphere transitions to the stratosphere, ~6-8 miles above earth’s surface at the poles). As we mentioned in this post, huge planetary-scale waves in the atmospher…   Read article

Across the United States, many are experiencing the first big blast of Arctic air of 2024. Coats and gloves are emerging from the closets, and heaters are working overtime, with temperatures dropping more than 25 degrees below normal in some parts of the country. But the question on our minds…the ever-looming question everyone asks when the cold air spreads across the country … the question that motivated this blog: Is the stratospheric polar vortex playing a role in this cold snap? Read on to find out! Stratospheric shenanigans If we had to characterize the behavior of the stratospheric polar vortex over the last week, we’d say it’s acting…squirrely. Living up to the celebrity sta…   Read article

When we last wrote two weeks ago, the forecasts suggested that the stratospheric polar vortex would continue to weaken and warm into January. Though there were a few days around the end of December where forecasts moved closer to predicting a full reversal of the west-to-east winds at 60 degrees North* that comprise a major “sudden stratospheric warming”, the ingredients did not fully come together. Instead, in the last few days there was a minor warming of the vortex. Temperatures in the mid-stratosphere (~19 miles above the surface) rose about 30 degC (55 deg F!) during the 6-day period between December 30 and January 5th, and the winds at 60 degrees North slowed considerably but did not r…   Read article

We threw plenty of information at you in our last post introducing the Arctic stratospheric polar vortex. So let’s take a step back and examine that information a little more closely. If the last post was the “meet cute” with the stratosphere, then this post is more like a first date, where we get to know the polar vortex and find out what it’s been up to lately. Tell me more about yourself We’ll start by taking a closer look at the average behavior of the temperature and wind patterns across the polar stratosphere throughout the year. The first thing you might notice is that the winds change direction in the late summer and spring. Or that the temperatures are colder in the winter tha…   Read article