“crazy” weather in the northern hemisphere

The final stretch of 2021 is marked by a extremely ‘crazy’ weather in Europe and elsewhere in the Northern Hemisphere, with practically opposite situations of polar cold and summer heat that occur simultaneously.

This circumstance occurs because the jet stream is extraordinarily wavy, in such a way that very high temperatures are produced in the ascending part of the ridge, while in its posterior part, there is a significant discharge of very cold air.

An obvious example of these aberrant extremes can be found in North America, where this weekend they have experienced horrifying contrasts. In Alberta (Canada) they had -30 ºC maximum, while in Texas they registered a hot 35.5 ºC. This is a difference of almost 60 ºC in little more than 3000 kilometers of distance.

The United States and Canada continue to experience fictional thermal anomalies. At Gulf of Mexico, Texas, Alabama, Tenneese or Kentucky makes a very abnormal heat for the time of year, with positive anomalies up to 14ºC. This situation contrasts with the cold that is discharging across the northwestern United States and Canada. In this sense, the states of Alberta or British Columbia they have negative anomalies between 20 and 25 ºC. There the maximums will not exceed -30 ºC.

In fact, yesterday cold records were pulverized in northwestern Canada, with –50.9º and Rabbit Kettle o -50.1º and Deadmen Valley. These are the lowest temperatures since 1998, reports Vancouver meteorologist Thierry Goose.

Smoothness in Europe, except Norway and Russia

Here, on the European continent, we are also living atmospheric contrasts, although not of the North American magnitude. Much of the old continent is under a rather soft air mass, with winds from the south and southwest in height and in the ascending part of the jet stream. In this way, we find positive abnormalities between 2 and 8 degrees that come to the Baltic Sea.

In our country is where today we will find the tmilder temperatures in all of Europe: the expected maximums will reach the 26 ºC in points of the Canary Islands or 24 ºC in the Valencian Community and Murcia.

This soft and almost summery atmosphere contrasts with the extreme cold in Norway and points of Russia. There the negative anomalies reach 8 ºC. For example in Oslo or Moscow will be below -10ºC all day.

Reinforced polar vortex at the north pole

The main cause of this softness and absence of cold in Europe is found in a reinforced and very strong polar vortex at the north pole, from Greenland to the extreme north of Canada through the Arctic. There is a very important cold pump, with values ​​down to -80 ºC in the stratosphere that translate into -40 ºC in points of Canada, as we have already told, and in Greenland. At the moment, this cold pump has neither corridors nor door to exit and discharge in lower latitudes at least until next year.

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