I'm happy to report that the models continue to show a pattern change for next week. The timing has even been sped up a bit with snow and rain starting as early as Tuesday morning. This storm should last through at least Wednesday morning in the Alps and at least Friday morning in the Pyrenees. 

As this storm drops down from the north, however, the ruthless stationary blocking ridge will cut it off from the flow. This will cause the storm to drift to the southwest and stall for several days. The models don't agree on how far southwest the low will track, nor on where the storm will track once it finally returns to the prevailing west-to-east flow. This creates some uncertainty regarding how long the precipitation will last during this period. 

So while there is decent confidence in what happens as the storm crosses the Alps and moves to the southwest, the period following that phase of the storm is less clear. Here is the upper-level pattern from the European model through Sunday the 17th. You can see next week's storm drop down through the North Sea, into western Europe, before drifting southwest and stalling over Spain.

Towards the end of the GIF, the resilient ridge breaks down, allowing the cut-off low to finally rejoin the flow and move off to the east. This model also shows a large upper-level trough of low pressure dropping down into the region now that the ridge is gone. The other models have this trough much farther east though, so the details of this next potential storm remain unclear.

Ok, let's look a little closer at the storm for next week. As the cut-off low shown in the GIF above approaches the western Alps, favorable orographics and large-scale lift associated with the low will produce moderate to heavy snow. First, as the storm approaches the region, northerly winds will lead to snow on the northern side of the central Alps.

As the closed low moves south of the Alps, the winds will shift to the east, favoring the eastern side of the southwestern Alps.

Changes to the storm track could shift these areas of greatest accumulation a bit, but the models have been coming into better agreement regarding these regions. You can see the Pyrenees getting in on the action too thanks to the north and northeast winds this storm track will bring to this range.

I will wait a day or two before getting into more detail on what happens once this storm stalls and eventually moves off to the east.

Although there are some differences in the location of the next upper-level trough to impact the region, both the ensemble and deterministic models show this feature. I think at this point it's more a matter of who will get the most snow from this system between the western and eastern Alps. This is still about 10 days out so the exact details need to be ironed out as we get closer, but this is a positive development.

Next post on Sunday.

Thanks for reading the Europe Daily Snow!

Luke Stone
Forecaster, OpenSnow