Last weekend was probably an absolute early winter highlight for many freeriders. Saturday (4.12.) was sunny and cold across the board - and a bit of fresh snow on a soft base made for excellent conditions. At around 2000 m near Innsbruck, it was minus 16° C on Saturday and even during the extra speedy ascent, fingers and toes didn't really want to thaw out. The descent was of course more than worth the effort, which is why we were back in the same area on Sunday. But in completely different conditions: A few layers of clothing already fell off during the first short ascent in the morning. The thermometer confirmed our sweating, at -4° it was a whole 12° warmer in the same place than the day before. The frosty times of the previous week were over and a large trough over the Atlantic began to shovel warm air into the Alpine region. Low pressure areas rotate in an anti-clockwise direction. If, as in this case, a low pressure area is located to the west of Europe, cooler air from the north arrives in the south, while the warm air from the south is transported to us. We are "at the front of the trough" - or at the wrong end of the air conditioning system.
Foehn situation with a sharp rise in temperature
Warm, humid air flowing from the Mediterranean towards the Alps almost always means, yes exactly, a foehn. The weather station in Ellbögen in Tyrol is a good example of when the Föhn sets in: The wind direction turns to the south on Sunday night (5.12.) and the wind picks up strongly. The rise in temperature is just as clear. The station measures the air temperature (red curve) and the dew point (blue curve). If the two curves are approximately the same, the humidity is high; if the dew point is lower than the air temperature, the air is dry. When the hairdryer sets in, the two curves diverge: the dry wind starts to destroy the snow.
Not much has changed since Sunday. In the morning, you can feel every single groove in the piste, which was groomed the evening before and then froze hard, and in the afternoon you can plough through slush: the spring conditions are great.
A massive cold front
However, just as quickly as the temperatures rose last weekend, they are falling again. The cold front, already announced as "massive!" in many weather forecasts, reaches the Alps and brings a sharp drop in temperatures. There will be precipitation, especially in the relevant north-facing areas. Friday will continue with clouds and snow showers in the north, while south of the main Alpine ridge you can expect strong north föhn and correspondingly more relaxed conditions. On Saturday, a warm front will serve up a second helping of snow for the northern Alps, which should mean the best powder conditions with hardly any base, and even powder conditions with hardly any base and extreme winds in the east.
Outlook
Next week will be very interesting in terms of weather: permafrost from Greenland to Athens is a distinct possibility at the moment...
