Day Risk Profile

Low

Moderate

Later

Avalanche Problems

Dry avalanches, whole day

Persistent weak layers 1

N, NE, E, SE, W, NW

above 2200m

Faceted 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 exist in the Snow deposited on the ground in a multiplicity of layers.EAWS glossary in particular on steep shady slopes. In very isolated cases dry avalanches can be released in the Snow layers deposited from earlier precipitation, prior to fresh fallen snow. Old snow layers consist of metamorphosed snow crystals.EAWS glossary and reach medium size. The Locations delineated by aspect or altitude where avalanches can trigger and people or objects are at risk.EAWS glossary are barely recognisable. Caution is to be exercised on steep, rather lightly snow-covered shady slopes in little used backcountry terrain. The Avalanche Warning Service currently has only a small amount of information that has been collected in the field, so that the avalanche danger should be investigated especially thoroughly in the relevant locality.

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.

Source: SLF Avalanche Bulletin Interpretation Guide

Wet-snow avalanches, as the day progresses

Wet snow 2

N, E, S, W

below 2500m

As the day progresses as a consequence of warming during the day and solar radiation there will be an appreciable increase in the danger of wet avalanches. This applies in particular on very steep north facing slopes below approximately 2500 m, as well as on very steep east, south and west facing slopes between approximately 2500 and 3000 m. Wet avalanches can additionally in some places be released in the weakly bonded old snow by people. Wet avalanches can reach large size in isolated cases. Backcountry tours and ascents to alpine cabins should be started early and concluded timely.

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.

Source: SLF Avalanche Bulletin Interpretation Guide

Snowpack & Weather

Snowpack

Despite the warm temperatures, the dry air means that the surface of the Snow deposited on the ground in a multiplicity of layers.EAWS glossary will freeze during the clear night into Friday to become capable of bearing loads. Sunshine will cause it to soften quickly.

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 be triggered by human activity in some places.

Higher up, the Snow deposited on the ground in a multiplicity of layers.EAWS glossary is still dry. While there are still 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, no dry avalanches have been reported for days.

Weather review for Thursday

After a clear night, conditions were sunny.

Fresh snow

Temperature

At midday at 2000 m, between +7 °C in the southwest and +4 °C in the northeast

Wind

Light to moderate northeasterly

Weather forecast to Friday

After a clear night, it will be sunny. With a zero-degree level of around 3300 m, it will be mild.

Fresh snow

Temperature

At midday at 2000 m, between +7 °C in the north and +9 °C in the south

Wind

Mainly light

Outlook to Sunday

The nights will be clear, the days sunny. The zero-degree level will be around 3000 m. The winds will be mostly light.

In the early morning, touring conditions will be favourable over a wide area. Each day, the danger of wet avalanches will increase appreciably as the day progresses. Tours and hut ascents should be started early and finished in good time.

Source

SLF

Issued

23 Apr 15:00 UTC

Valid until

24 Apr 15:00 UTC

Next update

24 Apr 15:00 UTC