Central Prealps
Stoos
Stable day. Low, with wet snow and gliding snow named together — one of them visible at the surface, the other buried.
Day Risk Profile
Avalanche Problems
Wet snow + Gliding snow
1
Field notes
Wet snow
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.
Gliding snow
Almost impossible to predict precisely, even when the warning signs are visible. A crack visible on the snowpack surface formed by snow-gliding on steep, and particularly grass-covered slopes. Areas below slopes with visible glide cracks should be avoided whenever possible due to threat of gliding sluffs or avalanches.EAWS glossary — gaps that open in the Snow deposited on the ground in a multiplicity of layers.EAWS glossary down to the ground — are often precursors to release, but they don't tell you when. A glide avalanche can release minutes after the cracks appear, or weeks later, or not at all. Some release without any visible warning. Avoid lingering anywhere near glide cracks: above them, alongside them, or below in the runout.
Snowpack & Weather
Snowpack
During the mostly clear night into Monday, the surface of the Snow deposited on the ground in a multiplicity of layers.EAWS glossary will freeze above approximately 2000 m once again to become capable of bearing loads. Sunshine will cause it to soften during the course of the day.
Moisture penetration into the Snow deposited on the ground in a multiplicity of layers.EAWS glossary is well advanced. The most precarious areas are slopes where 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 layers deposited from earlier precipitation, prior to fresh fallen snow. Old snow layers consist of metamorphosed snow crystals.EAWS glossary are becoming wet for the first time. At present, this mainly affects north-facing slopes between approximately 2200 and 2500 m, and east- and west-facing slopes between approximately 2500 and 2800 m. On south-facing slopes, moisture penetration into the snowpack extends as far as the Areas above approximately 3000 m (particularly glaciated areas).EAWS glossary. In Grisons, the weak layers in the old snowpack are the least deeply buried, which means that 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 can also occasionally be triggered by human activity.
In areas higher up, where the Snow deposited on the ground in a multiplicity of layers.EAWS glossary is still dry, 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 layers deposited from earlier precipitation, prior to fresh fallen snow. Old snow layers consist of metamorphosed snow crystals.EAWS glossary are still present, but are unlikely to be triggered anymore.
In general, no further avalanches triggered by human activity have been reported in the last seven days.
Weather review for Sunday
After a mostly clear night, it was mostly sunny and mild during the day.
Fresh snow
-
Temperature
At midday at 2000 m, between +10 °C in the west and south and +7 °C in the east
Wind
Light to moderate from northerly directions
Weather forecast to Monday
Sunday night into Monday will be mostly clear. During the day, it will be mostly sunny with some cumulus clouds in the afternoon.
Fresh snow
-
Temperature
At midday at 2000 m around +8 °C
Wind
Mostly light from westerly directions
Outlook to Wednesday
The nights into Tuesday and Wednesday will be mostly heavily overcast and for this reason outgoing longwave radiation will be low. In the south, it will be overcast during the day with precipitation, especially on Tuesday. The snowfall level will drop from 2800 m to 2400 m. On Wednesday, there will be only a small amount of precipitation. In the north, it will be heavily cloudy on Tuesday with showers and thunderstorms. On Wednesday, it will be partly sunny in the afternoon with showers. The snowfall level will be around 2200 to 2400 m. The wind will be mostly light to moderate from westerly directions. In total, 10 to 20 cm of snow will fall in the Areas above approximately 3000 m (particularly glaciated areas).EAWS glossary over both days. The danger of dry avalanches may increase slightly in the high alpine regions. Where there is reduced outgoing longwave radiation during the night and with rain, the danger of wet avalanches will increase even in the early morning.