Is winter coming to Germany in February?

Winter could not yet assert itself sustainably over Germany this season, and apart from a bit of wintry teasing, there was nothing that could be called winter. What about February – does winter have a chance?

Wbetween waiting. There is no better way to summarize the current weather situation. A peak over Germany will shift slightly to the west in the coming week and will allow cold air masses of polar origin to flow south along its eastern high pressure gradient.

weather change

The first cold gust of wind first hits Germany on Sunday and does not really affect the weather. Another push towards the end of the week has a greater potential to create a change in the weather. Temperatures fall with an increase from north winds to +1 to +4 degrees and as cold air masses are brought into higher altitudes, it is up to lower altitudes Snow, sleet or sleet to rely on. Winter conditions can set in over about 400 to 600 meters.

Is winter coming to Germany in February?
Forecast according to the US weather model: A change of weather is imminent after the middle of the week with a falling snow line

How is the weather in February?

The fact is that the weather in January and all winter was far too hot, and the number of snow days of 7.4 days was far behind the long-term average. It is therefore not surprising that we are currently receiving many inquiries about whether or not Winter can still pick up speed in January or February? Basically, however, winter has two options, which we will take a closer look at today.

The high must be on the Atlantic

This is the first principle that applies in winter. Although other constellations also lead to winter weather, the current general weather situation allows for only a few options. What remains is the western shift of the high-pressure system to the Atlantic Ocean.

This is the only way to meet two conditions. The altitude blocks the Atlantic frontal zone, making a western weather situation impossible, and on the other hand, a meridional ground current is initiated, which – with the mound on the Atlantic – results in a north-south current over Germany, Austria and Switzerland.

winter weather

And only when these parameters are set, something happens to the winter – not before. We have compared what it might look like in the following weather maps. The variations range from wet and cold weather (northwestern weather conditions), where winter occurs as an option from the middle heights, to a very wintry weather conditions, which can last into February (preservation tendency). And yes, should the height of winter still prevail over the last decade of January, it may too large parts of February are wintery.

From left to right: wet and cold, beginning winter, mid winter
Forecast after selected control runs: from left to right – wet and cold, beginning winter, mid winter

The polar vortex until February

The other path that leads to one wintry to midwinter February weather can lead is the polar vortex, which tends towards instability towards the end of winter.

Strong heating

These instabilities can be initialized from stratospheric altitude. Starting with a smaller heating, under certain conditions, a larger heating – ie sudden stratospheric warming made possible. A prerequisite for this is that the temperatures at this altitude rise from around -80 to +0 to +16 degrees within a short time. If this is the case, the chances of a major overhaul are not bad. From this point on, the wind at stratospheric altitude changes its direction of rotation from west-east to east-west, causing turbulence in the lower air layers – and thus the polar vortex – about 4 to 8 days later. This can end in a so-called displacement (displacement of the polar vortex), a polar vortex division or a complete destruction of the polar vortex (final heating).

If one looks at the current calculations of stratospheric gyre, there is only a slight minor warming that emerges in late January. So nothing moves and in this state it would have no effect on the weather. This phenomenon is still to be observed in the coming days, as a sharp warming is expected in February.

Will a greater warming in the stratosphere bring winter to Germany? No, not necessarily, but the conditions for this are improved with a disturbed polar vortex.

In early February a slight slight warming at stratospheric level
Forecast According to the US weather model: a slight warming at stratospheric level in early February

Unstable polar vortex

However, it does not always have to be a major warming that leads to an unstable polar vortex or a polar vortex split. There are other constellations as well. For this to be the case, however, a disturbance pulse must occur in the form of a high-pressure system which enters the polar vortex. We selected these varieties and compared them.

A polar vortex divided into different shapes
Forecast after selected control runs: a polar vortex divided into different shapes

The edge factors

First of all – a polar vortex split is not automatically a winter bringer, as can be seen on the middle weather map above (zone approach), but a polar vortex split brings a fresh push in the anchored weather kitchen and the time from February to April is the usual time for a polar vortex to become unstable.

An indication of a weak or unstable polar vortex is a negative AO index. The current calculations differ widely and make it possible to conclude that in February there may be something with a disturbed polar vortex. To make the relationship even clearer, there are two positive and ten clearly negative variants. The rest is neutral.

In order for something to happen with the onset of winter over Germany, the NAO index should also be calculated negatively, reflecting the relationship between the Icelandic low and the Azores high. As the situation is at present, the NAO index is assessed predominantly positively. An absolute conclusion on one possible onset of winter in February can not be deduced from the marginal factors.

What the forecast models calculate

Europeans and Americans plan the second trough advance a little further west on January 20, increasing winter opportunities for the end of next week. Europeans also simulate the high in the period too close to Germany. It was not until 25 January that certain instabilities within the polar vortex appeared, which could cause the mound from Europe to wedge up in the direction of Iceland and Greenland and subsequently lead cold air masses south over Europe.

But that is a more hypothetical assumption at the moment. Actually after Forecast of Europeans until 25 January a sustained onset of winter down to the lowlands is not to be expected.

Americans’ forecasts are almost identical. January 25 is the height too close to Europe. In addition, an extremely unstable polar vortex is emerging. The high shifts to the Atlantic and the low-pressure systems over Scandinavia fell south. This is the variant that Winter in February can lead to Germany, Switzerland and Austria.

First the high near Europe, followed by an unstable polar vortex with an Arctic eruption over Central Europe
Forecast according to the European (left) and the American (right) weather model: First high close to Europe, followed by an unstable polar vortex with an Arctic eruption over Central Europe

In a nutshell: what to expect from the weather in February

If you go by the probability, then in the period from the 15th to the 25th of January a wet and cold weather character can set in, with the 17th, 21st and 22nd of January it will be cold Snow, sleet or sleet down to lower altitudes, but daily values ​​of +1 to +5 degrees are too mild for the season – and yes, in mid-January and mid-February it’s actually time for midwinter …

Only in late January and early February do temperatures drop to 1,400 meters to a level where one can discuss winter from the lower intermediate heights between 300 and 500 meters. ONE a persistent flat winter can not be identified in the control runs. Rather the familiar wet and cold pattern with wintery ambitions from the middle layers.

A wet and cold weather with winter ambitions from the middle heights
Forecast according to the average of all control runs: a wet and cold weather with winter ambitions from the intermediate heights

The weather forecast for February for the long-term models

If it goes by the CFSv2 model, this is the way it should be The weather in February 2022 can be +1 to +2 degrees too hot compared to the long-term average from 1961 to 1990 (91/20: -0.1 to +0.9 degrees). The precipitation forecast is clearly too wet in relation to the long-term target value.

Weather forecast according to the European weather model

The long-term outlook for the European weather model calculates February as significantly too hot with a deviation of +1 to +3 degrees and normal to clearly too warm compared to the average from 1991 to 2020 with a difference of -0.1 to +1.9 degrees. The precipitation outlook is slightly positive for northern Germany and a little too dry for the southern part.

The weather in February according to NASA

Also in weather trend NASA does not indicate that the February weather is too cold. The deviation from the climate average for 1961 and 1990 is +1 to +2 degrees, and the trend is up to +3 degrees (91/20: -0.1 to +1.9 degrees). The rainfall balance should be a little too dry.

In terms of status

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