Keystone
Plenty of sunshine, occasional fog and rising temperatures: a high is building over the North Atlantic that’s here to stay. At least for the next few weeks.
For winter sports fans, this news is only partially positive: In addition to lots of sunshine and occasional fog, there is hardly any snow or other precipitation during the persistent high pressure system. And the temperatures are rising – especially in the mountains.
According to forecasts by Weather News the nights won’t be as cold as this week. During the day the temperatures climb to 5 to 10 degrees. In sunny Alpine valleys even double-digit plus values. By the middle of the week, the zero-degree limit should rise to 3,000 meters above sea level. Meteorologists only calculated the first fruitless precipitation from February 20th.
The “Omega High”
If a high like the one that is currently building over Europe lasts for a particularly long time, it is referred to as an “omega high” in meteorology. The weather current is in the shape of a Greek omega and hardly moves. This blocking high pressure layer occurs when the normal west-east movement of the weather systems comes to a standstill and the prevailing weather is effectively blocked at the same point.
Weather News
Sea «SRF Weather» such blocking weather conditions bring extreme weather events with them. In summer, they usually cause heat waves or droughts like in 2003 and 2018. In winter, they constantly bring in cold polar air that brings cold, ice and snow.
So what does the dry weather mean?
High pressure areas last longer in winter, which is why dry spells are not uncommon. Even when it’s cold, no water comes down the drain, the precipitation remains in the form of snow and the ground is frozen, explains Klaus Marquart from Meteo News. The drought is not yet a problem for agriculture either, since it is still too early to sow seeds in February.
For the meteorologist, on the other hand, the previous winter with little snow has been a challenge. In Valais, Ticino or Grabünden and on the entire southern side of the Alps, it has been too dry since the beginning of December.
In general, the snow conditions in the Swiss Alps are below average compared to the norm, Marquart continues. If nothing changes, this means less meltwater in the spring. The protective snow cover for the glaciers also disappears earlier in a warm or hot summer, the bare ice melts away and is then unprotected. That would be another low blow after the summer of 2022, which was catastrophic for the glaciers, explains the expert.
According to Marquart, the drought is becoming more and more of a problem, even though there is little rainfall in March and April. Then the vegetation period begins again and the evaporation rates increase. The risk of forest fires is already increased on the south side of the Alps.