Trigger-sensitive snowdrift accumulations are being generated on the northern flank of the Alps and in Lower Valais in particular as a result of fresh fallen snow and, at high altitudes, moderate-strength northwesterly winds.
Bonding of the recently fallen snow and freshly generated snowdrifts from this last week with the generally thin but weak old snowpack lying beneath it is unfavourable on west-facing, north-facing and east-facing slopes above 2000 m. These avalanche prone locations are found frequently in northern and central Grisons and in the Lower Engadine. Avalanches have been triggered from this transition zone during the last few days particularly in these regions. Certain signs of alarm are indicators of the weak old snowpack.
Below 2000 m on the northern flank of the Alps, gliding snow avalanches continue to be possible on grass-covered slopes. These releases can grow to medium size.

Skies were heavily overcast and intermittent snowfall was registered in the northern and the western regions more than anywhere else. The snowfall level descended from 1200 m down to below 800 m during the course of the night. On the southern flank of the Alps and in the Upper Engadine it was quite sunny and dry.

Between Wednesday midday and Thursday midday, the following amounts of fresh snow were registered above 1500 m:

• northern flank of the Alps, Lower Valais, western part of the Jura region: 10 to 20 cm;
• in the other regions of Switzerland, less; or else it remained dry.
  

At midday at 2000 m, between -7 °C in the northern regions and -3 °C in the southern regions.

• Winds during Wednesday night were blowing at moderate strength, intermittently at strong velocity, from southwesterly directions;
• during the daytime winds were blowing at light to moderate strength from the northwest.

On Thursday night, persistent snowfall is anticipated on the northern flank of the Alps which will extend down to low lying areas. In the latter part of the night the snowfall will slacken off. During the morning hours on Friday, skies in the northeastern regions will still be overcast, subsequently it will become quite sunny, as in the other regions of Switzerland.

Between Thursday midday and Friday morning, the following amounts of fresh snow are anticipated above 1000 m:

• northern flank of the Alps from the Schilthorn to Liechtenstein: 20 to 30 cm;
• remaining parts of the western sector of the northern flank of the Alps, western Lower Valais, northern Grisons: 10 to 20 cm;
  
• in the other regions of Switzerland, less; or else it will remain dry.
  

At midday at 2000 m, in the northern regions at -9 °C, and in the southern regions at -7 °C.

• Winds will be blowing at moderate to strong velocity from northwesterly to northerly directions at high altitudes and on the southern flank of the Alps; in the other regions of Switzerland blowing at moderate strength;
• in the southern regions, a foehn wind will be blowing.

During Friday night snowfall is expected to set in from the northwest. On Saturday and on Sunday, snowfall is anticipated over widespread areas, but in the furthermost southern regions it will remain dry. The snowfall level in the western regions will ascend to 1800 m on Saturday morning, in the eastern regions to 1400 m. Subsequently the snowfall level will descend down to low lying areas. North of an imaginary Rhone-Rhine line and in the Lower Valais, 40 to 70 cm of fresh snow is anticipated by Sunday afternoon, even more in the furthermost western part of Lower Valais.
Avalanche danger levels are expected to increase over widespread areas as a result of the snowfall. On the northern flank of the Alps and in the furthermost western part of Lower Valais, danger level 4 (High) could be reached regionally at high altitudes. In central Ticino and in Sotto Ceneri, avalanche danger levels are not expected to change significantly.