Day Risk Profile

Moderate · lower end of the band

Moderate

Later

Avalanche Problems

Dry avalanches, whole day

Persistent weak layers 2-

N, NE, NW

above 2600m

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 bottom section of the Snow deposited on the ground in a multiplicity of layers.EAWS glossary in particular on very steep shady slopes. In 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, even to the trained eye. Caution is to be exercised on steep, rather lightly snow-covered shady slopes in little used backcountry terrain.

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 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 isolated cases be released in the weakly bonded old snow by people. Avalanches can reach large size in isolated cases. Backcountry tours and ascents to alpine cabins should be 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

With the mild temperatures of the last two weeks, moisture penetration into the Snow deposited on the ground in a multiplicity of layers.EAWS glossary is already well advanced. At present, it is only increasing slowly. North-facing slopes at altitudes between 2200 and 2500 m are most susceptible to moisture penetration. On east- and west-facing slopes, the critical altitudes are somewhat higher, at approximately between 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. It is on these Direction in which a slope faces as indicated by compass direction of the fall line; i.e. a north slope faces in a northerly direction.EAWS glossary and at these altitudes that isolated large 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 may be triggered naturally.

In Grisons, the 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 the least deeply buried, and it is here 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 are likely also to be triggered by human activity.

At higher altitudes, the Snow deposited on the ground in a multiplicity of layers.EAWS glossary is still dry. 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, but no more dry avalanches have been reported in recent days.

Weather review for Tuesday

It was mostly sunny, and cloudy at times on the central and eastern parts of the northern flank of the Alps.

Fresh snow

Temperature

At midday at 2000 m, between +4 °C in the southwest and 0 °C in the northeast

Wind

Light to moderate from westerly directions

Weather forecast to Wednesday

In the far south, the night into Wednesday will be cloudy with some rain; it will become increasingly sunny during the day. In the north, it will be mostly sunny after a mostly clear night.

Fresh snow

Temperature

At midday at 2000 m, between +4 °C in the southwest and +1 °C in the northeast

Wind

Light.

Outlook to Friday

After clear nights, it will be sunny during the day with light winds. The zero-degree level will be just below 3000 m on Thursday and will rise to around 3300 m on Friday.

The danger of dry avalanches will not change significantly. The danger of wet avalanches will increase during each day. Off-piste skiing and hut ascents should be completed in good time.

Source

SLF

Issued

21 Apr 15:00 UTC

Valid until

22 Apr 15:00 UTC

Next update

22 Apr 15:00 UTC