Day Risk Profile

Low

Moderate

Later

Avalanche Problems

Dry avalanches, whole day

No distinct problem 1

N, NE, E, SE, SW, W, NW

above 2200m

As a consequence of new snow and a moderate northwesterly wind, small wind slabs will form in some localities. The number and size of Locations delineated by aspect or altitude where avalanches can trigger and people or objects are at risk.EAWS glossary will increase in the Areas above approximately 3000 m (particularly glaciated areas).EAWS glossary. Apart from the danger of being buried, restraint should be exercised in particular in view of the danger of avalanches sweeping people along and giving rise to falls.

Field notes

SLF uses this label when no single problem dominates the assessment, often on lower-danger days. It doesn't mean conditions are safe: any avalanche type is still possible, and normal caution applies. On stable days this is usually a signal to enjoy the mountains with general awareness; on less-stable days where the assessment is still inconclusive, it's a signal to be cautious specifically because there's no clear pattern to follow.

Source: SLF Avalanche Bulletin Interpretation Guide

Wet-snow avalanches, as the day progresses

Wet snow 2

N, E, S, W

below 2400m

Outgoing longwave radiation during the night will be reduced in some case. 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 steep north facing slopes below approximately 2400 m, as well as on steep east, south and west facing slopes between approximately 2500 and 3000 m. Wet avalanches can be released in the weakly bonded old snow by people. Isolated 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 penetration of the Snow layers deposited from earlier precipitation, prior to fresh fallen snow. Old snow layers consist of metamorphosed snow crystals.EAWS glossary can indicate the danger. 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

With the mild weather, moisture penetration into the Snow deposited on the ground in a multiplicity of layers.EAWS glossary is well advanced. At present, north-facing slopes at altitudes between 2200 and 2600 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 extends as far as the Areas above approximately 3000 m (particularly glaciated areas).EAWS glossary. It is especially 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 critical altitudes that isolated large or occasionally even very 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 in particular, 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 slab avalanches are likely also to be triggered by human activity. 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 continue to be a possible indication of a weak snowpack.

At higher altitudes, where the Snow deposited on the ground in a multiplicity of layers.EAWS glossary is still dry, 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 must continue to be assessed with caution. However, dry avalanches have been rare in recent days.

Weather review for Saturday

The night into Saturday was mostly clear. During the day it was mostly sunny with high cloud and some cumulus clouds developing in the afternoon.

Fresh snow

Temperature

At midday at 2000 m around +8 °C

Wind

Mostly light, sometimes moderate from westerly directions

Weather forecast to Sunday

The night into Sunday will be partly cloudy. During the day it will be mostly cloudy in the northeast and showers and thunderstorms are possible. The snowfall level will drop from around 2200 m to 1900 m. In the south and west it will be partly cloudy. Isolated showers are possible, but sunny spells are also to be expected.

Fresh snow

In the north, 5 to 10 cm is possible above 2500 m. Locally, there may also be heavier precipitation in the form of showers.

Temperature

At midday at 2000 m, between + 3 °C in the northeast and + 6 °C in the west and south

Wind

Light to moderate from the northwest, becoming stronger in the afternoon

Outlook to Tuesday

In the west and south it will be quite sunny after mostly clear nights. In the northeast there will be somewhat more cloud and it will only be partly sunny. As the day progresses, isolated showers are possible.

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

18 Apr 15:00 UTC

Valid until

19 Apr 15:00 UTC

Next update

19 Apr 15:00 UTC