An anomalous anticyclone comes in from mid-December, but watch out for the ‘frost effect’

December changes face: Before the Christmas holidays, we expect truly erratic weather with consequences for many of our regions.

From December 15 to 20 He will be the perfect hero I amresistance (with partly marine and partly African contributions) This, along with warm air aloft, will dominate the scene in much of central western Europe.
In essence, we are faced with a broad area of ​​high pressure that effectively blocks any Atlantic disturbance or cold air irritation coming down from the North Pole.
The most notable anomaly concerns the sector temperature: It is usually one of the coldest periods of the year, on the contrary, deviations from the climate average of +7/8°C are expected, especially in the mountainous areas. Therefore, we will see very high temperatures during the high altitude season and very stable values, especially in the plains, especially at night. A common phenomenon developed during winter anticyclonic periods.

As expected, strong night-time temperature inversions may develop with sub-zero temperatures and snow formation, particularly at the Valpadana and Alpine valley sites (Frost effect) cold, high humidity and heavy air, stagnant in the lower layers, favors the possible formation of frost and frost in the flat areas of Piedmont, Lombardy, Emilia Romagna and Triveneto. It will be over all open air areas (less so in city centers) that will benefit the most from this particular winter event, where temperatures will allow.

However, as often happens in winter, atmospheric stagnation caused by an anticyclone can also cause A Stagnation of air in the lower layers, Special ValpadanaAs a result of creation the fog oh Low clouds And with temperatures that are very cold even during the day. detail, Misty shores and dark skies They will show in the plains Lombardy, Emilia Romagna, Veneto e Friuli Venezia Giulia.

Finally, it is worth underlining a truly insidious and dangerous phenomenon for our health. Several days of no ventilation would be beneficial Contamination of pollutants After all, due to high pressure, the lower layers of the atmosphere must be “crushed”. environmental parameters Frequently Too badwith serious consequences for our health (respiratory diseases, etc.).
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