It will start snowing heavily in the Alps this weekend. After a northern Stau which will drop some freshies on Thursday and Friday, a new storm will kick in. This will be a pretty intense storm and it will result in the base for winter in the high alpine.
In this forecast:
The northern Stau was first visible on the weather maps about eight days ago. The models are managing the long term models better and better (30% probability back in the eighties, between 50-75% nowadays), but I already mentioned that there were some uncertainties. The models don't perform that well during Autumn because of the different kind of weather they have to deal with, such as cold air in the north, warm air in the south, the temperature of the Atlantic Ocean and the Mediterranean, but also the expected snow cover. The devil is in the details during this time of the season and it's hard to say that the northern Stau will arrive with the intensity you can see above, let alone that 54 centimeters will come down in St. Anton. In the end I'm pretty happy with the improved models, because it makes it easier for me to say something about the near future.
Talking about that, we can definitely expect a northern Stau, but the precipitation is tempered by the strong anticyclone Rafael. This high pressure area pushes Gisi a bit too far to the east and also ensures that the air pressure around the Alps is a bit high with 1015 to 1020 mbar.
The current doesn't come straight from the north, but is deflected to the east when it arrives at the Alps. This partly has to do with the fact that the current simply hits the Alps, but the fact that Gisi is pulling the current away is definitely of influence as well. She's moving east instead of the southeast and she's moving fast. When you take a look at [these maps](https://earth.nullschool.net/#2016/11/03/0000Z/wind/isobaric/700hPa/grid=on/orthographic=0.01,49.18,3000/loc=-22.758, 56 158) you will see that the current will turn to the west just before it hits the Alps. Sad but true. So yeah, there will be a northern Stau, but the execution died in the details. The result is around 10-20 cm of freshies that will come down on Thursday and Friday with the snow line around 1000 meters.
The little storm I told you about yesterday will hit continental Europe on Friday and will influence the weather in the Alps the next five days. It will arrive at the Alps on Saturday and you can expect some fireworks. You can no longer call it a small storm anymore. Warm air is moving to the north (red arrow) and in the meantime cold air from the Arctic is moving south (blue arrow). This cold air will drop some snow in Scotland, but even more to the Pyrenees. Check out the snow map here.
The separation of hot and cold air will be exactly above the Alps this weekend and the differences will be striking on Sunday. Warm air generally means lot of moisture and with cold air around the chances on a big dump are getting bigger!
November 2014 began tremendously turbulent as well. The Alps formed the stage where hot and cold air had constant battles and which caused significant snowfall in the southern Alps. They had more than 500 centimeters of fresh snow in the Gotthard region in less than two weeks. Austria was still green in the middle of December, but the resorts in the main alpine ridge already had a good base. The north side of the Alps had to wait till Christmas before the first snow came down. This will be a better start of the winter in the southern Alps compeared to last season. Maybe it will be as good as winter 13-14 when we already had eight PowderAlerts by the end of December and the southern Alps drowned in snow. I'm not saying that the snow that will come down the next couple of days will mark the start of a great winter, but it's better than nothing.
There was already half a meter of snow visible on the snow maps yesterday, but today there's up to a meter of snow in teh forecast in the resorts in Slovenia, but also around the Italian Selle Nevea. It looks like this on the snow maps.
I love the colors on the snow maps. But if you look at the precipitation maps of the GFS, it gets even better. You see the numbers rise up to 2 meters!
It's hard to say if those amounts of snow will actually come down, because there simply are too many uncertainties. Our snow maps are partly based on the European weather model and they are quite positive about what will happen after the weekend. The American model is not that positive. We'll see what happens.
The models keep battling after Monday. The European model is showing cold air and snowfall. The American model warm air. Lots of snow for the high alpine in both cases, but a lower snow line would be nice!
Stay stoked. Morris