Suche
Mein Konto
Winter is coming sooner than expected: there is a threat of cold chaos from St. Nicholas onwards!
A sudden winter weather change in Germany could be expected from St. Nicholas Day. Find out more about the background and effects.
Winter is coming sooner than expected: there is a threat of cold chaos from St. Nicholas onwards!
The run-up to Christmas not only brings with it a contemplative mood, but also exciting weather developments. From St. Nicholas Day, December 6th, a complete winter change could begin in Germany. While mild temperatures prevail at the beginning of December, current meteorological models indicate cold weather. The az-online.de reports on possible frosty nights, snow showers and lasting winter episodes that could soon shape the picture of the Advent season.
A key factor in this change is the state of the polar vortex. This large, rotating area of air around the poles has a significant influence on the weather conditions in Europe. The polar vortex can transition into stable and unstable states, the latter of which can direct cold air masses towards Central Europe. A weaker polar vortex, which could be observed during this time, favors the formation of blocking high pressure areas in the North Atlantic. These often persist for a long time and can trigger snowfalls if the conditions are right, also reports Wikipedia.
The role of the Arctic Oscillation
Another crucial aspect is the Arctic Oscillation (AO), a phenomenon that describes the difference in air pressure between Arctic and mid-latitudes. The AO has two phases, of which the negative phase is particularly relevant as it can transport cold polar air increasingly to Europe. A negative AO phase has been commonly associated with cold waves in Europe in the past, as exemplified by the 2018 cold anomaly. There, both the AO and NAO indices had fallen massively into negative territory, which favored the cold spell. The possibility that this will happen again this year creates anticipation - and a little concern when you think about slippery conditions and cold temperatures Wikipedia.
Given the forecast changes in the weather, signs of a possible change are already showing in the atmosphere. If weather conditions are favorable, a “cold air reservoir” could be mobilized from the east of the continent, bringing the cold air masses to Central Europe. Such a scenario would not only create a frosty atmosphere, but would also delight numerous winter fans and make the contemplative pre-Christmas season all the more beautiful.
It should be noted that the mild temperatures at the beginning of December are due to a stable westerly position. However, this can quickly change if the above-mentioned weather phenomena - such as the instability of the polar vortex and the Arctic Oscillation - occur. The interplay of large-scale interactions and various indices makes the Christmas season exciting, and who knows, perhaps the first snow will soon be on the plates of the Christmas markets.