Bollettino valanghe

Yukon

Mar 11 – 12, 2023Avalanche Canada
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Archiviato · scaduto 4 years ago

Pericolo valanghe

Mon
Tue
Alta quota
2 · Moderato
Limite del bosco
1 · Debole
Sotto il limite
Senza grado
Apri la mappa completa

In sintesi

Head to lower elevation, sheltered terrain to find the best conditions and avoid avalanche problems. The alpine holds hard wind slabs and persistent layers of concern.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Wind slabs may remain reactive on west to south aspects in the alpine as winds continue to redistribute available snow. Hard wind slabs can feel supportive and be stubborn to triggers. Be aware of the potential for them to surprise you once you hit the weak spot.

    Terrain around Powder Valley and Paddy Peak holds more snow available for transport than other areas. Fresh and reactive wind slabs are more likely to develop here.

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–3

    A weak layer of surface hoar and/or a crust buried about 100 cm deep have produced large, widely propagating avalanches in the alpine as recently as Tuesday. These avalanches have been observed on north and south aspects and some have been remotely triggered by riders.

Avalanche Summary

On Friday several recent size 2 wind slabs were observed in the Paddy Peak area. Observers noted active wind transport still occurring with snow available for transport.

On Tuesday, a size 2.5 persistent slab avalanche was remotely triggered by skiers on a ridgetop in the alpine. The slab propagated widely on a thin, rocky southeast aspect and it stepped down to basal facets lower on the slope.

Confidence

Moderate

Snowpack Summary

Outflow winds from the north continue to scour exposed terrain, creating waves of sastrugi in more sheltered terrain, and forming wind slabs on southerly aspects. Areas north of White Pass have more loose snow available for transport. Sheltered terrain in side valleys to the east and west of White Pass still may hold softer snow for riding.

The middle of the snowpack is very firm and settled. There is a surface hoar layer buried 60 cm (Powder Valley, Tuthsi, Paddy Peak) to 120 cm (White Pass) deep in sheltered, mostly north facing terrain features. On other aspects this layer exists as a crust and facets. Natural and human triggered avalanches have occurred on these layers recently and it remains a concern in alpine terrain.

At the base of the snowpack large sugary crystals persist.

Weather Summary

Friday Night

Flurries overnight with trace accumulations. Moderate to strong northeasterly winds continue.

Saturday

Skies clear in the afternoon with possible scattered flurries. Moderate to strong northeasterly wind. Alpine high -20 ˚C.

Sunday

Sunny. Light to moderate northeasterly wind. Alpine high -18 ˚C.

Monday

A mix of sun and cloud with light easterly wind. Alpine high of -15 ˚C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for areas of hard wind slab on alpine features.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Seek out sheltered terrain where new snow hasn't been wind-affected.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Regioni coperte