Weather: DECEMBER with BOTTO! Frosty start, then Big News for CHRISTMAS. The Latest Update is Amazing
Latest news for DecemberDecember is now upon us, and with it too winter season that will start with BOTTO!. The Announcements most important just arrived concerns thestart of the month which could be to say the least icy. And the surprises they do not end here, on the contrary. We are not talking about the much desired gifts to put under the tree, but the hypothesis of snowfall up to low altitude if not in the plains I enter Christmas on some Italian regions.
The reason is to be found in the behavior of the Polar vortex, which could trigger cold waves descending from the Arctic already with the beginning of next December.
They try to understand better than what it is, doing clarity on what to all intents and purposes is an update of the models … creepy.
During the autumn season, at high latitudes, beyond the Arctic Circle, if it forms a mighty cyclonic structure which takes the name of Polar vortex. We can imagine it as one large area of low pressure which then lasts throughout the winter and often influences its fate. Everything is enclosed inside the cold that continually occurs on the Arctic ice sheet and which finds its outlet through the depression centers directed towards the South and therefore as far as Italy. These low pressure centers are i responsible for phases of intense bad weather and drastic drops in temperatures. The behavior of the Polar Vortex, however, it is not always the same.
For instance, if it is strong and compact, the cold remains confined to the North Pole, reason for which on Italy a stable weather with high pressures and milder air. If, on the other hand, the Vortex goes in crisis, the effects can be more or less intense. Sometimes it can literally split into two or more parts, moving with its load icy and unstable currents towards the South. When it splits / weakens the probability that the cold also reaches our Peninsula grows considerably. This configuration was the origin of the most intense waves of frost which invested the whole of Europe (including Italy) in 1929, 1963, 1985, 1996, 2012 just to name a few.
The it causes of this rift is to be found in thesignificantly warmer air flow in the upper atmosphere, in technical terms stratwarming.
STARTING DECEMBER: the European Center (map below) has just confirmed an influx of “warmer” air in the stratosphere (between 15 and 30 km in height) with values up to + 15 ° C compared to the average species between North-Eastern Siberia and Alaska.
It is a quite anomalous event in this period of‘year and in fact it could destabilize right away the Polar Vortex, with consequences also on the European sector. Indeed, this is the medium and long-term trend of the American model GFS which, already with the beginning of December, foreshadows masses of icy air descending from the Arctic ready to launch their attack on Europe, thus provoking also on Italy, especially in the Central North regions, an early arrival of cold and of name at low altitude.
Here’s why a snowy surprise might materialize well before Christmas, a bit like what happened last year, when the snow reached many areas of the Po Valley, whitening the cities of Turin, Milan, Padua, Venice and Bologna. The prospects in the following weeks are for an alternation between phases of high pressure interrupted by sudden polar blitzes with the return of bad weather.
In short, what already happened in 2020 could be repeated, with two snowfalls up to the plains in December. We will keep you posted.
Cold air mass descending from the North Pole already in early DecemberAbnormal stratospheric heating of the Polar Vortex