Bollettino valanghe

Lizard-Flathead

Apr 10 – 11, 2021Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 5 years ago

Pericolo valanghe

Mon
Tue
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole

In sintesi

New snow and strong winds continue to form fresh wind slabs at treeline and above. Watch for newly formed and reactive wind slabs as you transition into wind affected terrain. 

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1.5–2.5

    10-25 cm of convective new snow and strong southwesterly winds are forming fresh wind slabs on lee features at treeline and above. 

  • Cornices

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Unlikely - Possible
    Dimensione
    1.5–2.5

    Cornices are large and looming along many ridgelines and have likely grown with the recent wind. 

    Strong solar radiation and warming are common triggers for cornice failures which could trigger large avalanches.

Confidence

High -

Weather Forecast

  

SATURDAY NIGHT: Partly cloudy / Light, northwest ridgetop wind / alpine low temperature -10 / Freezing level valley bottom.

SUNDAY: Mostly cloudy with isolated flurries; 0-5 cm. / Light, southwest ridgetop wind / alpine high temperature -2 / Freezing level 1500 m.

MONDAY: Mix of sun and cloud / Moderate, northeast ridgetop wind / alpine high temperature -3 / Freezing level 1400 m.

TUESDAY: Mix of sun and cloud / Moderate, northeast ridgetop wind / alpine high temperature -2 / Freezing level 1400 m.

Avalanche Summary

Small wet loose avalanches were reported in this region on Friday.

Snowpack Summary

10-25 cm of convective new snow and strong southwesterly winds are forming fresh wind slabs on lee features at treeline and above. This brings recent snow totals to 30-40 cm. The recent snow is sitting on hard crusts on solar aspects and a mix of wind affected or soft surfaces on shady aspects.

 Cornices are large, looming, and capable of triggering large avalanches when they fail.

The mid-pack is firm and well settled. Some faceted snow and a decomposing melt-freeze crust can be found near the base of the snowpack that may become a concern when the next big warm-up arrives.

Snow line is slowly creeping up the mountains to roughly 1400 m in elevation. Check out this MIN report for more details on the access from common staging areas.

Glide cracks releasing as full depth glide slab avalanches become more common in the spring and are extremely difficult to predict. Best practice is to avoid slopes with glide cracks.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid freshly wind loaded terrain features.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Regioni coperte