Gruyère

Increase in avalanche danger in particular in the west.

A little snow is lying. As a consequence of new snow and a strong westerly wind, small wind slabs will form in the course of the day in particular in gullies and bowls and behind abrupt changes in the terrain. These are to be evaluated with care and prudence in extreme terrain. Restraint should be exercised because avalanches can sweep people along and give rise to falls.

Snowpack The fresh fallen snow is being intensively transported by strong-velocity winds. In the more deeply embedded layers inside the old snow cover on north-facing slopes above 2200 to 2400 m, as well as on south-facing slopes above approximately 2800 m, there are expansively metamorphosed (faceted) and loosely-packed layers of snow evident. These layers are prone to triggering, particularly in the regions ranging from southern Valais over the Gotthard region as far as Grisons. Observed weather review Saturday, 14.01.2023 During the night in the northeastern regions more than anywhere else, there was precipitation registered. The snowfall level descended from 1600 down to 1000 m. During the daytime hours in Grisons and in the southern regions, it was quite sunny, in the remaining regions of Switzerland skies were overcast amid high-altitude clouds. Fresh snow Between Friday afternoon and Saturday morning, the following amounts of fresh snow were registered above approximately 2000 m:

• central and eastern sectors of the northern flank of the Alps: 5 to 10 cm; from Muotatal as far as the Alpstein as much as 15 cm;
• in the remaining regions of Switzerland, less; or else, it remained dry.

Temperature At midday at 2000 m, 0 °C over widespread areas, in the northwestern regions at +2 °C. Wind Winds on the northern flank of the Alps and in general at high altitudes were blowing at strong velocity, intermittently at storm strength, from westerly directions; in the other regions of Switzerland winds were blowing predominantly at moderate strength. Weather forecast through Sunday, 15.01.2023 During the nocturnal hours a warm front will move into Switzerland from the west, during the daytime hours a cold front will take its place. Skies will be heavily overcast. In the northern and the western regions, precipitation is expected which will be intensive in the furthermost western regions. In Grisons and in the southern regions the nighttime skies will be dry, a bit of precipitation is anticipated only during the course of the day. During the night the snowfall level on the northern flank of the Alps will temporarily ascend to approximately 2200 m, in the other regions of Switzerland the snowfall level will lie at approximately 1500 m. During the course of the day it will descend down to low lying areas. Fresh snow By Sunday afternoon the following amounts of fresh snow are anticipated above 2200 m:

• northern and furthermost western parts of Lower Valais, Vaud Alps: 20 to 30 cm; along the French border as much as 50 cm;
• remaining regions of the northern flank of the Alps and of Lower Valais, northern Upper Valais: 10 to 20 cm;
• in the remaining regions of Switzerland less; in the furthermost southern regions it will remain dry;

In the Jura region, precipitation will initially fall as rain, 5 to 10 cm of fresh snowfall is anticipated ultimately at high altitudes. Temperature At 2000 m in the northern regions, +3 °C subsequently descending to -8 °C; in the southern regions at approximately -4 °C. Wind

• Winds on the northern flank of the Alps and in general at elevated altitudes will be blowing at strong velocity to storm strength from westerly to southwesterly directions on Saturday night, subsequently slackening off somewhat during the daytime hours on Sunday;
• in the valleys of the north, strong foehn winds will prevail on Saturday night more than anytime else;
• in the other regions of Switzerland, predominantly moderate winds will be blowing from southwesterly directions.

Outlook through Tuesday, 17.01.2023 Skies will remain heavily overcast and intermittent snowfall is expected to fall down to low lying areas. Between Sunday midday and Tuesday midday in the western and the Jura regions, 20 to 40 cm of fresh snow is anticipated. The westerly to southwesterly winds will be blowing at strong velocity on Monday, then gradually slacken off on Tuesday. Avalanche danger levels are expected to increase in the western regions, Danger Level 4 (high) could be reached in the furthermost western part of Lower Valais. In the remaining regions of Switzerland, avalanche danger levels are also expected to increase, but only slightly.