March 2016: Weaker polar vortex slows down spring in Europe
UBIMET: temperature rise in the stratosphere of around 50 degrees, still no spring in sight
Vienna 03/09/2016 – This year March has offered little spring weather so far. One of the reasons for this situation is the strong recent temperature rise in the stratosphere. The temperatures in this layer at 10 to 50 kilometers altitude are warming up to around 50 degrees. According to weather service UBIMET, the consequence of this sudden temperature rise in the upper levels is relatively cold weather in sight for the lower ones. A glance at the statistics also shows that March in general has the potential to be quite a diverse month. Those who are looking for spring can probably find it in the southern regions of Europe.
The relatively cold weather in March this year is - among other reasons - also caused by a strong, recent temperature rise in the stratosphere. In this layer, 10 to 50 kilometers above the North Pole, a deep low pressure system known as “polar vortex” usually forms during winter and can affect and modify the weather patters at European latitudes. Inside the polar vortex, the air cools down and temperatures drop to around -80 degrees every year. Experts are referring to a proper stratospheric warming when it exceeds 50 degrees. The impact of such a temperature rise is of major significance for Europe: “The polar vortex is responsible for driving the Westerlies in Central Europe”, says UBIMET meteorologist Josef Lukas. “If the polar vortex collapses, for instance through a sudden and strong temperature rise, the large-scale pattern shifts and cold air from the North and East can force it’s way to the South, towards the Alps. This is exactly what is happening right now.”
Where to find spring in Europe at the moment?
While Northern and Eastern Europe is dominated by proper winter weather with lowest values around -10 degrees, Southern Spain, Portugal or the Canary Islands are blessed with spring weather of up to 22 degrees. “The warmest temperatures throughout Europe are expected in Cyprus, with around 27 degrees during the weekend”, explains Lukas.