Large-scale weather situation: changeover to the west
For quantities and details on the fickle snow line, please refer to the PowderAlert. The WeatherBlog takes a look at the larger structures that we have to thank for the positive, snowy and negative, warm aspects of the weather situation: After a long period of moderately exciting weather (sunny over widespread high fog, pleasant touring conditions with some quite good snow), we're now getting a properly turbulent westerly including storms, rain, snow and the potential for surprises.
The storm has to do with the very tight westerly flow that has formed over the Atlantic and is blowing away the last remnants of the calm "swamp weather" today. The jet stream is rushing zonally from west to east. There are several smaller waves embedded in it, which cause rapid weather changes when they reach the Alpine region. In contrast to recent weeks, we are no longer dealing with a blocking situation in which disturbances have to travel around a large area of high pressure before they make it to the Alps from unusual directions. The direct slide from the Atlantic to the Alps is free again.