It's warm again in Europe. The jet stream lies north of the Alps and so we find ourselves in a warm bubble. Warm air is being pushed from the Mediterrenean to the north and we have to go to Siberia or the west of Ireland for cold air. And the weather comes from the west of Ireland for the next 72 hours. An active depression (with a central pressure around 965 hPa) is cruising at the Atlantic at the moment and sent his scout Wymar ahead.
This storm depression will bring lots of snow (but also great waves in the north of Spain), but it will be quite difficult. Wymar is bringing cold air to the Alps and the jetstream will manage to bring that cold air to the western Alps.
On Tuesday night the front with cold air will reach the French Southern Alps and it will start to snow. The snow line will be very high at first, but it will drop in the night to Wednesday. The real snowfall will start on Wednesday. Cold air is making its way through the Gulf of Genoa and the Lac Léman to the western Alps. The result is a sandwhich of fronts causing the snow line to drop to around 1550-1900 meters in the night from Wednesday to Thursday and it will start to snow in the French Southern Alps, the Isère and Savoie, the Haute Savoie and Wallis, the Piemonte and the northern Piemonte, Gotthard and Lombardia. The snowfall will expand to the north of Switzerland. The last snow will come down near the Gotthard and the Ortler on Thursday and the sun will come out right after. I expect around 15-25 centimeters of freshies around 2000 meters and 25-45 centimeters of freshies above 2700 meters. The most snow will come down in the Stau areas of the Ecrins, the Mont Blanc, the Gotthard and the Mont Viso. That's great news for the high alpine areas in the western Alps that will get some freshies, but....
High pressure will dominate the weather in the Alps again from Friday. The temperatures will rise and blue skies will dominate. The next couple of days we'll focus on the snow that will fall later this week and keep an eye on the developments in the near future.