Bollettino valanghe

Microwave-Sinclair

Jan 17 – 18, 2023Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 4 years ago

Pericolo valanghe

Thu
Fri
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Apri la mappa completa

In sintesi

Start on small features and gain confidence before moving into bigger terrain. The recent snow is mostly loose, but if a slab is present, it could easily avalanche on a layer of weak, feathery, surface hoar crystals.

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2.5

    It may seem strange to have a storm slab problem when there hasn't been much new snow, but based on some avalanches observed on Saturday, previous storm snow may be settling into a more cohesive slab over a layer of weak, feathery surface hoar crystals. Not much wind transport was observed over the weekend, and the wind did not seem to be a factor in these reported avalanches. If you notice whumpfs or shooting cracks, retreat to mellower terrain.

    It may be hard to predict the exact terrain where this problem exists. Approach steep terrain cautiously, or choose to remain in mellower terrain until this layer is tested with a larger load.

    This MIN Report does a great job of explaining how the avalanche problem might present itself.

Confidence

High

Avalanche Summary

No new avalanches were reported before 4pm on Monday.

On Saturday, several size 2 avalanches were reported at Hankin, Ashman, and in the Babines. These avalanches were easily triggered by the weight of a rider, and they propagated across whole terrain features. They were sliding on a layer of weak, feathery surface hoar crystals, 20cm below the snow surface.

Snowpack Summary

20-30 cm of generally soft snow sits above a layer of surface hoar crystals in sheltered areas. If wind or warmish temperatures have formed any of this snow into a slab, expect it to avalanche under the weight of a rider. See the avalanche summary for recent reports of avalanches on this layer.

A weak layer of facets that formed during the arctic outbreak in December is buried 30 to 60 cm deep. Observations suggest it is fairly widespread, but rounding and gaining strength, and is not reactive to triggering under the current conditions.

Weather Summary

Monday Night

Cloudy. Possible trace of snow expected. Light southwest wind. Alpine temperature around -7°C.

Tuesday

Cloudy. 2-5 cm of snow expected. Alpine wind increasing to moderate south through the day. Alpine temperature around -5°C. Snow possible to valley bottom.

Wednesday

Cloudy in the morning, sunny in the afternoon. No new snow expected. Strong southwest alpine wind. Alpine temperature falling to around -10ºC.

Thursday

Mostly cloudy. Possible trace of snow expected. Strong southwest alpine wind. Alpine temperature rising to around -5ºC.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
  • Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.

Regioni coperte