In collaboration with meteorologist Kevin Clotier
The polar vortex is a major player in cold weather in the Northern Hemisphere. Although it is present throughout the year, it weakens during the summer. However, here he is, setting the table for winter.
Nice to know – The polar vortex is an area of ​​low pressure located in the Northern Hemisphere, which extends from the surface to the stratosphere. It acts like a large cyclone, covering the entire North Pole of the world, and is the result of the large difference in solar radiation between the equator and the North Pole. It generally contains the coldest mass of air in the hemisphere.
still holding power
The reduction of the sun’s influence in the northern regions, typical for autumn, effectively allows it to be regained. During September and October, the polar vortex gains strength – and quickly.
There are two elements to be considered: its temperature and its pressure. Its cooling is accelerating, deprived of the heat of the solar star. In addition, its size and effect increase as the pressure at the heart of the polar vortex drops, preparing for the return of cold weather.
It usually reaches its peak around November, when it is at its strongest. So this acquisition is happening at this very moment, several kilometers above our heads.
However, the exact behavior of the vortex still holds many mysteries. It is difficult to accurately predict its development in the next few months.
Remember that La Nia is firmly established in the Pacific Ocean for the third consecutive winter. This may have an effect on the behavior of the polar vortex. Whatever be the case, the winter season will be shaped by these two important players.
some possibilities
One thing is certain: the polar vortex has a direct effect on regions located in the Northern Hemisphere – of which Quebec is clearly a part. If its effects can be felt during the fall, in winter the polar vortex actually lays all its cards on the table.
In short, two main orientations are possible: a strong vortex or a weak vortex.
a stronger vortex This generally means that the coldest air remains confined to the Arctic regions. It is therefore less likely to make deep dives in North America and Europe, thereby limiting cold escapes. This can be seen as a shield that holds back the cold air. In such a situation, winters are making less effort towards our latitudes.
However, the reverse is also possible. Sudden stratospheric heating may still be in the way. If this happens, the polar vortex will lose wings. a weak vortex Containing arctic masses is more difficult. Cold spells are more frequent and more significant in North America and Europe. Worse: such a reference could favor an atmospheric blockage over Greenland, encouraging prolonged glaciation in Quebec.
