In the lower part of the snowpack there are weak layers of expansively metamorphosed (faceted) crystals on west-facing, north-facing and east-facing slopes above approximately 2200 m in nearly all regions of Switzerland. From central Valais as far as Grisons, as well as in general in those places where the snow is shallow, the snowpack layering is least favourable. In the western part of Lower Valais and on the northern flank of the Alps, the weak old snow is frequently blanketed over by thick layers. In general, spots where the old snowpack is shallow can be most easily triggered.
As a result of strong to storm-strength winds on Friday, a great deal of snow will be transported. The snowdrift accumulations are prone to triggering.

On Wednesday night there was snowfall registered over widespread areas extending down to low lying areas. In the morning hours on Thursday the precipitation slackened off significantly and skies brightened up from the west, as well as along the southern flank of the Alps.

Fresh snow between Wednesday afternoon and Thursday afternoon:

• northern flank of the Alps, northern Lower Valais: 30 to 50 cm;
• remaining parts of Lower Valais, northern and central Grisons, Jura region: 20 to 40 cm;
• Upper Valais, Ticino, southern Grisons: 10 to 20 cm.

The following amounts of fresh snow were registered between Monday afternoon and Thursday afternoon:

• northern flank of the Alps, northern Lower Valais: 40 to 80 cm;
• remaining parts of Lower Valais, Ticino, northern and central Grisons: 20 to 40 cm, 10 to 20 cm in the other regions of Switzerland.

At midday at 2000 m, between -9 °C in the northern regions and -6 °C in the southern regions.

• Nocturnal winds in the Jura region were blowing intermittently at storm strength, during the daytime at light to moderate strength from northwesterly directions;
• winds on the Main Alpine Ridge from the Simplon Pass into the Upper Engadine were blowing at moderate to strong velocity from northwesterly directions;
• in the other regions of Switzerland, winds were mostly light to moderate from northerly directions.

Following brief spells of bright skies during Thursday night, skies will be heavily overcast during the early morning hours on Friday. Starting in early morning precipitation will set in from the west, which will subsequently spread to the southern regions and, by midday, also to the eastern regions.

Between Friday morning and Friday afternoon, the following amounts of fresh snow are anticipated:

• in the Jura region, on the northern Alpine Ridge from the furthermost western part of Lower Valais into the Aletsch region: 20 to 30 cm; in the furthermost western regions as much as 40 cm;
• in the remaining parts of the northern flank of the Alps and in the remaining parts of Lower Valais: 10 to 20 cm;
• in the Upper Valais, in the Ticino, and in Grisons: 5 to 10 cm.

• Temperatures will temporarily rise somewhat during the nighttime hours, subsequently drop again.
• At midday at 2000 m, between -6 °C in the northern regions and -9 °C in the southern regions.

• Winds during the early part of the night will be predominantly light, and subsequently,
• in the northern regions
  during the morning hours blowing at strong to storm strength from southwesterly directions; in the Alpine valleys moderate-strength foehn wind will prevail;
  in the afternoon, predominantly strong velocity winds from northwesterly directions.
• in the southern regions
  blowing at light to moderate strength, intermittently at strong velocity from southwesterly directions;
  during the afternoon shifting to northwesterly at high altitudes.
  

In the northern regions, skies will be heavily overcast on both days. On Saturday on the northern Alpine Ridge, an additional 15 to 30 cm of fresh snow is anticipated; in the other regions of Switzerland, less. On Sunday, only a few centimetres of fresh snow is anticipated. Winds at high altitudes will be blowing intermittently at strong to storm strength from northwesterly to westerly directions. In the southern regions it will be predominantly sunny on both days, on Sunday partly sunny in the inneralpine regions. On Sunday, temperatures in general are expected to rise significantly.
The avalanche situation will remain critical over widespread areas.