The past weekend was interesting in terms of weather and regrettable in terms of skiing. After heavy rain during the night, temperatures of around 20 degrees were measured in many places during the day on Sunday. The leader in Austria was Pottschach (Lower Austria) with 23.2° - a new national record for February. What was going on?
During Saturday (20.2.), a warm front approached the Alps from the west and in the evening it began to snow or rain heavily in places. While it initially snowed down to the valleys in the west of Tyrol (despite the forecast, one was almost tempted to hope!), it rained further east right from the start. For the most part, subtleties in timing were decisive for the aggregate state: in the confusion of the front, does the precipitation come first and then the warmth, or vice versa? For example, at the Muttekopfhütte (Imst, Tyrol) and Brunftbergtiefe (Berchtesgaden) stations: In Imst, the precipitation starts a few hours earlier. Temperatures are already rising, but there will be enough snow until around midnight. In Berchtesgadenerland it is already warm when the precipitation starts slightly later.
Such minor details are unlikely to have been decisive for the skiing conditions on Sunday (equally wet at both locations), although the overall snow depth in Imst suffered visibly less due to the initial snowfall. In any case, the warm front left behind a considerable sector of warm air, which ensured fairly summery temperatures. The air mass boundary between cold in the north and warm in the south has been running more or less sharply from west to east since then and lies slightly north of the Alps, which yesterday's cold front with a few flakes on the northern slopes of the Alps was unable to change. While a strong Scandinavian low is steering cold air towards us on its western side, a small trough in the area of Spain is counteracting this and directing warm Mediterranean air to the north. The air mass boundary lies at the meeting point, preventing cold air from spilling over the Alps.
What's next?
It remains exciting and possibly not as bleak for winter fans, at least in the mountains, as one would almost expect based on the course of winter so far. An advance of cold air south of Greenland is causing a low to grow (cyclogenesis). As the already known Azores High is once again inflating strongly, this low will be pushed onto a fairly southerly track and come to rest over the Iberian Peninsula at the weekend. It will most likely cause extremely heavy precipitation there. At the same time, warm, humid air will once again be directed towards the Alps at the front of the low, which may also lead to heavy accumulation precipitation in the south and Föhn in the north.
There is currently a very interesting option for the further development and the meteorological start of spring (1 March), which is nice to look at but should of course still be treated with caution: In this variant, the still strong Azores High favors a drift of the polar vortex far to the south, whereby a northerly flow with cold air and precipitation in Central Europe would once again provide a winter feeling over a large area.
