Sunny and dry in the Alps. Will the weather change?


By meteomorris on 5 December 2016 · 0

After a fantastic start in early November with lots of snow falling deep into the valleys in the north of the Alps and snowfall in the southwest of the Alps right after, our favourite mountain range is dominated by sunshine. A powerful high pressure area named Uwe keeps every significant storm at distance and it will stay like this in most parts of the Alps for the next 7 to 10 days. As a result it is dry and sunny in the Alps, although there was a striking difference between the models this morning and that provides some perspective for the north of Austria. In this forecast:

  • Dominant high pressure
  • Snow for Austria?
  • Long term: a negative NAO index?

Dominant high pressure
Dominant high pressure

Dominant high pressure

High pressure area Uwe settled itself above the Alps last week. There are no dynamics or whatsoever in the weather right now. The jet stream is thus forced to choose a route that is far away from the Alps. Such stable high pressure systems can block the weather for days or sometimes even weeks. High pressure areas cause typical inversion weather, which means cold air in the valleys. The cold air can't escape because of the clouds and the sun simply doesn't have the power to break through the clouds. Above the clouds however it's sunny. The air is dry and the views are amazing, but the temperature drops rapidly during the night.

The snowfall in our weather model for the next six days...
The snowfall in our weather model for the next six days...

This high pressure area could bring us some serious problems. You don't have to expect new snow and the clear nights will bring surface hoar on north faces and other parts of the mountain that lie in the shadow. It could even result in a complete layer of sugar snow that will be a problem with the next dump.

GFS vs ECMWF
GFS vs ECMWF

Snow for Austria?

When you look closely at the map above (and can interpret the isobars) you will immediately notice a significant difference. On the left you see the forecast for next Monday according to the American GFS model, on the right you see the forecast of the European model ECMWF for the same day. The map on the right (the European model) is interesting because it shows a temporary current from the north which will bring snow to the north of Austria on Monday. Let's hope this forecast is correct. It is a special variation in the models, and only the first calculation. Tonight we will know more becaue the ECMWF comes up with a new calculation. If that current from the north and is visible again ánd it will also be visible in the American model, than we can get ready for some snowfall. I'll let you know tomorrow. For the rest of the Alps: forget about any form of precipitation for the next 7 to 10 days.

NAO index negative on the long term
NAO index negative on the long term

Long term: a negative NAO index?

Right now we are dealing with a positive NAO index. Storm depressions are kept at a distance, but from mid-December the weather could change. That's still far away. Keep on dancing and pray for snow!

Stay stoked. Morris


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