Nock Mountains

Weak persistent layers become even easier to disturb during daytime changes

Weak persistent layers become even easier to disturb during daytime changes

The avalanche risk is moderate above the tree line and low below. In a few places that are often difficult to recognise, medium-sized slab avalanches can still be triggered by individuals, especially in the extended northern sector. This is in particular at the transitions from little to more snow. As the snowpack softens during daytime changes, deeper layers can be disturbed much more easily. Occasional wet snow slabs are then also possible in sunny slopes that have not yet been unloaded.

The snowpack can cool down well overnight and form a melt-freeze crust, which softens again during the day on sunny slopes. In general, the snowpack on sunny slopes is damp or wet up to high altitudes. In shady high altitudes, some of the snow surface is still soft, faceted snow, some of which has already crusted can form. Below this lies a now well-set and connected sequence of compact drift snow layers, but often a crust with angular crystals is still embedded in the upper area. The connection at the transition to the old snow foundation, which consists mainly of deep rime, is still poor to very poor and fractures can still be easily provoked here. Deep and sunny middle layers are often already snowed out.

Friday night will be mostly clear. Friday will be very sunny again and there will be good visibility, even if a little more high cloud and dust will spoil the sunshine somewhat. A weak to moderate southerly wind will set in on the main Alpine ridge. At 2000 metres it will be around 5 degrees, at 3000 metres around -2 degrees.

The number of avalanche prone locations in the persistent weak layer is only slowly decreasing. The outgoing longwave radiation is somewhat limited on Sunday night.