Bollettino valanghe

Purcells

Feb 25 – 26, 2022Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 5 years ago

Pericolo valanghe

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

In sintesi

The best riding and lowest hazard is in areas that haven't been wind affected.

Watch for pockets of wind slab on various aspects as you transition into exposed terrain around ridgelines.

Problemi valanghivi

  • Wind Slabs

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

    Watch for pockets of wind slab on all aspects in exposed terrain and around ridgelines due to recent variable winds. 

    Alpine features are the most likely culprits for wind slabs, but exercise caution in exposed treeline features with stiff snow as well.

    These slabs have formed on top of old crusts and hard wind-pressed snow and there is uncertainty about how quickly they will bond to old surfaces. 

Confidence

High -

Weather Forecast

THURSDAY NIGHT: Mostly clear with light northwest winds. Alpine highs of -10. 

FRIDAY: Sunny with a few clouds, light to moderate northwest winds (trending winder in the afternoon), and highs of -9.

SATURDAY: Sunny, moderate southwest wind, alpine highs of -7.

SUNDAY: Increasing cloud, moderate southwest wind, alpine high of -5.

Avalanche Summary

On Wednesday there was a report of several size 2 natural wind slabs caused by reverse loading in steep terrain. With clearing on Tuesday there was evidence of a natural avalanche cycle earlier in the week up to size 3 from deeper snowpack areas in the Purcells. On Tuesday there were also some small natural and skier-controlled wind slabs as well as a small remotely triggered wind slab reported.

On Sunday around Quartz Creek there were shooting cracks and several small avalanches triggered by snowmobiles in steep unsupported northeast creek features.

Snowpack Summary

Recent northeast winds have likely reverse loaded features forming wind slabs in unusual locations near ridgelines. In sheltered areas, 20-40 cm of recent snowfall sits over a mid-February drought layer consisting of melt-freeze crusts on solar aspects, and wind-pressed snow in other exposed terrain. A small layer of surface hoar may exist above the melt-freeze crust in sheltered areas in some locations.

Another layer of buried surface hoar sits 30-60 cm deep in the upper snowpack, most likely to be found and triggered on north aspects in sheltered areas. Though there haven't been reports of recent avalanches on this layer in this region, it is still on the radar of many operations and could potentially be triggered by large loads such as a cornice fall or a step-down avalanche. 

The lower snowpack is well consolidated, with a crust/facet layer found 100 to 150 cm deep. It is currently considered dormant but could become active later this season. Check out the forecaster blog for more information. 

Terrain and Travel

  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Be alert to conditions that change with elevation and wind exposure.

Regioni coperte