On Shrove Monday, low pressure system Ruzica disturbed the jesters in the German carnival strongholds. Low Susanna then put the finishing touches to the whole thing last night. Together with a strong foehn wind, the carnival in the Alps was also blown away by the wind
.
Initial situation:
Cold air is still flowing south from the polar region around Newfoundland, stimulating low pressure activity in the Atlantic. The flow situation is very zonal, meaning that lows are coming directly across the pond to Europe. The embedded disturbances are sometimes a little further south, sometimes further north and produce a rollercoaster of temperatures and snowfall limits. Most recently (i.e. until yesterday), the Alps were in an inflow with a southerly component. In combination with a corresponding pressure gradient, this resulted in strong south föhn in the northern Alps and the fresh snow in the west and south explained in the PowderAlert.
While the Alps were cooking up their own little soup of Föhn and südstau, something completely different was bubbling a little further north. The interestingly named low pressure system Ruzica was already causing strong winds in parts of Germany and France on Monday. There was also major damage in the southern half of England. Here the storm was called Imogen and caused power cuts and flooding, among other things. While the Air & Style in Innsbruck was canceled at the weekend due to foehn winds, the Rose Monday parades in Mainz and Düsseldorf had to be canceled due to Storm Ruzica (coming from the northwest). Yesterday, Tuesday, somewhere between central Germany and the main Alpine ridge, we were finally able to watch the tough battle between two Central European giants. Following in the footsteps of Ruzica, marginal low Susanna sent a powerful cold front into the race against the Föhn. Coming from the northwest, the front slowly approached the Alps, where the Föhn held out for a relatively long time, but eventually had to accept defeat.
Low Susanna brings cold front
Exemplary station data from Brauneckgifpel (Bavaria) and Patscherkofel (Tyrol). While the Föhn on Brauneck collapsed in the evening hours of February 9th with the arrival of the cold front, it lasted a few hours longer on Patscherkofel. Thanks to the Föhn-exposed location, wind speeds of almost 160 km/h were measured at the Patscherkofel summit (the carnival parade in Innsbruck was also canceled on Tuesday). In comparison, the quite stormy cold front only produced a fresh breeze here. At the Brauneck summit, the Föhn was strong, but lagged behind the wind peaks of the front (114km/h).
The unusually high lightning activity for the time of year also shows that the cold front has a lot to offer:
What's next?
Today, Wednesday, it is still snowing widely north of the main Alpine ridge, but not very heavily. Tomorrow, Thursday, it will clear up quickly in the morning and it will be relatively clear. From a large-scale perspective, the next relevant development is on the horizon for Sunday/Monday. At the moment, it looks as if the Azores High will succeed in pushing northwards, which could cause the current over the Atlantic to become more wavy again and end the westerly slide for the time being. The exact effects are still uncertain, but the potential for wintry conditions is not bad, or even quite spectacular with the current runs. Let's see what happens.
As usual, we'll leave the details of the fresh snow to the oracle - it'll be interesting to see.
