Central Grisons and Anterior Rhine
Albulatal
Day Risk Profile
Avalanche Problems
Persistent weak layers
3-
Field notes
Persistent Snowpack layer in which the crystals are poorly bonded and the layer has the potential to fail. Typical crystals in dry weak layers causing avalanches are : precipitation particles; surface hoar; faceted crystals; hollow crystals; graupel. Generally >1mm in size, loose grains with few bonds Wet weak layers can be formed by all snow crystal/grain types.EAWS glossary are very challenging to recognise. Distinctive noise (resembling a “whumpf” sound) occurring when a weak layer beneath a slab collapses. The air of the weak layer is forced outside the snowpack, with the resulting whumpf sound being heard. The sound usually indicates an unstable situation and can be accompanied by surface cracking. A whumpf is a clear avalanche alert.EAWS glossary sounds and shooting cracks are typical when present, but you can have a serious weak layer with no warning signs at the surface. Knowledge of how the Snow deposited on the ground in a multiplicity of layers.EAWS glossary has evolved is essential. SLF's travel advice is direct: travel conservatively, avoid terrain where the consequences of being caught are large, and treat the history of weather and snow as more important than what you can see today. Read the full bulletin.
Wet snow
2
Field notes
Rolling snowballs, deep penetration when you step or ski, and small natural slides are clear signals that the Snow deposited on the ground in a multiplicity of layers.EAWS glossary is losing strength. After a clear, cold night the surface often freezes into a strong supporting Layer of hard-compacted snow resulting from a melt-freeze process or wind.EAWS glossary, and conditions are favourable in the early morning. After a warm, overcast night, the problem may be present from the start of the day. Plan early returns and watch the runout zones below you.
Snowpack & Weather
Snowpack
North of a line from the Rhone to the Rhine and in the extreme west of Lower Valais, Snowpack layer in which the crystals are poorly bonded and the layer has the potential to fail. Typical crystals in dry weak layers causing avalanches are : precipitation particles; surface hoar; faceted crystals; hollow crystals; graupel. Generally >1mm in size, loose grains with few bonds Wet weak layers can be formed by all snow crystal/grain types.EAWS glossary in the Snow deposited on the ground in a multiplicity of layers.EAWS glossary are mostly thickly covered and are now hardly triggerable by human activity.
South of a line from the Rhône to the Rhine, the persistent Snowpack layer in which the crystals are poorly bonded and the layer has the potential to fail. Typical crystals in dry weak layers causing avalanches are : precipitation particles; surface hoar; faceted crystals; hollow crystals; graupel. Generally >1mm in size, loose grains with few bonds Wet weak layers can be formed by all snow crystal/grain types.EAWS glossary that have been a feature since the beginning of January are still present. However, the number of avalanche-prone locations has decreased significantly. Reports of avalanches and alarm signs indicate that the situation in Grisons remains the most precarious.
Snowpack layer in which the crystals are poorly bonded and the layer has the potential to fail. Typical crystals in dry weak layers causing avalanches are : precipitation particles; surface hoar; faceted crystals; hollow crystals; graupel. Generally >1mm in size, loose grains with few bonds Wet weak layers can be formed by all snow crystal/grain types.EAWS glossary in the lower part of the Snow deposited on the ground in a multiplicity of layers.EAWS glossary are being weakened as they become moistened for the first time. Wet The abrupt release of a slab of snow on a mountain slope. After crack initiation and crack propagation in a weak layer the released slab comprises 3 elements: The weak layer, the gliding horizon and the slab. If the slope angle is steep enough, the slab will glide down. If the slope is not steep enough, the slab will settle down on the failed weak layer. Possibly a whumpf sound will follow due to air pressed out of the weak layer. The fracture line will be sharp edged.EAWS glossary are possible as the day progresses. These can occur naturally but can also be triggered by winter sport participants, at present mainly on sunny slopes below approximately 2600 m.
Weather review for Tuesday
In the south, there was broken cloud during the night with a little snow still falling above 1600 m early on. Skies were otherwise clear overnight. Conditions were sunny and mild during the day.
Fresh snow
From Sunday afternoon until precipitation stopped on Monday evening:
- Bernina region: 10 to 20 cm
- rest of the main Alpine ridge from the Simplon Pass to the Ofen Pass and south of there: up to 10 cm
Temperature
At midday at 2000 m, around +2 °C in the north and -1 °C in the south
Wind
Mainly light
Weather forecast to Wednesday
After a clear night, conditions will be sunny and mild.
Fresh snow
-
Temperature
At midday at 2000 m, around +2 °C in the north and 0 °C in the south
Wind
Light
Outlook to Friday
After a clear night, conditions will be sunny and mild on Thursday. The zero-degree level will be 2600 m in the north and 2000 m in the south. There will be a light to moderate southwesterly wind. Overnight to Friday and during the day, high cloud will pass through in the west, elsewhere the night will be clear and the day sunny. Temperatures will remain mild and winds will be light.
The danger of dry avalanches will continue to decrease, but only slowly in Grisons due to the weak Snow deposited on the ground in a multiplicity of layers.EAWS glossary structure. Each day, the danger of wet avalanches will increase somewhat as the day progresses.