Bollettino valanghe

North Columbia

Feb 2 – 3, 2021Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 6 years ago

Pericolo valanghe

Thu
Fri
Alta quota
4 · Forte
Limite del bosco
4 · Forte
Sotto il limite
3 · Marcato
Apri la mappa completa

In sintesi

Touchy storm slabs are sitting on a very weak layer of surface hoar which is very likely to be reactive to human triggers, even in low angle terrain. Avalanches may be larger than expected due to the presence of this weak layer.

Problemi valanghivi

  • Persistent Slabs

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

    New snow loads have potential to awaken deeply buried weak layers.

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Very Likely
    Dimensione
    1.5–3

    Touchy storm slabs are sitting on a very weak layer of surface hoar which is very likely to be reactive to human triggers, even in low angle terrain. Avalanches may be larger than expected due to the presence of this weak layer.

Confidence

Moderate - Uncertainty is due to the timing, track, & intensity of the incoming weather system. Forecast snowfall amounts are uncertain.

Weather Forecast

  

MONDAY NIGHT: Snow; 15-20 cm. / Strong, south ridgetop wind / alpine low temperature -7 / Freezing level 600 m.

TUESDAY: Cloudy with flurries; 0-3 cm. / Moderate, southwest ridgetop wind / alpine high temperature -4 / Freezing level 700 m.

WEDNESDAY: Mostly cloudy with sunny periods / Light, northwest ridgetop wind / alpine high temperature -8 / Freezing level valley bottom.

THURSDAY: Cloudy with flurries; 3-5 cm. / Moderate, west ridgetop wind / alpine high temperature -9 / Freezing level valley bottom.

Avalanche Summary

A widespread natural cycle and numerous skier triggered storm slab avalanches up size 2 were reported on all aspects in the Gorge area west of Revelstoke on Sunday. These storm slab avalanches were running on a weak layer of surface hoar that was buried by the recent storm. See one of numerous MIN reports Here.

Touchy storm slabs are sitting on a very weak layer of surface hoar which is very likely to be reactive to human triggers, even in low angle terrain. Avalanches may be larger than expected due to the presence of this weak layer.

Snowpack Summary

25-30 cm of new snow as of Monday afternoon brings recent snow totals up to 45 cm. Rising freezing levels throughout the storm has caused rapid slab formation. These touchy storm slabs are sitting on multiple weak layers of surface hoar. The first being below the most recent snow, and the second down 50-60 cm.

Observers continue to find a third layer of surface hoar from earlier in January down 70-100 cm. in sheltered, open areas near treeline. 

The mid and lower snowpack is generally well settled and strong. 

Terrain and Travel

  • Keep in mind that human triggering potential persists as natural avalanching tapers off.
  • Be aware of the potential for large avalanches due to the presence of buried surface hoar.
  • Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.
  • Avoid exposure to overhead avalanche terrain, avalanches may run surprisingly far.
  • Be aware of the potential for human triggerable storm slabs at lower elevations, even on small features.

Regioni coperte