Bollettino valanghe

Northwest Coastal

Mar 22 – 23, 2017Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 10 years ago

Pericolo valanghe

Fri
Sat
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato

In sintesi

Wind slabs are growing while a deeper weakness continues to produce large avalanches. Evaluate the terrain and snowpack carefully and stay aware of overhead hazards.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2
    A steady pulse of unsettled weather will build fresh wind slabs in the lee of exposed terrain. Recent winds have also built touchy cornices.
  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    2–3
    A weak facet/crust layer from late February has produced several large human triggered avalanches the past few days. Triggering this layer is most likely in shallower areas, but a small wind slab or cornice fall could act as a natural trigger.

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

THURSDAY: Unsettled weather with flurries bringing 5-15 cm of snow, moderate and gusty south wind, alpine temperature around -6 C.FRIDAY: More flurries with 5-15 cm, moderate south wind, alpine temperature around -4 C.SATURDAY: Still more flurries with 5-15 cm, moderate southwest wind, alpine temperature around -6 C.

Avalanche Summary

Reports from Tuesday indicate the persistent slab problem is alive and well throughout the region. A few natural size 2-2.5 avalanches were triggered in the Bear Pass / Stewart area by solar input or cornices. A skier also remotely triggered a size 2 avalanche on the February facet/crust interface on a moraine feature around 1150 m (40 cm deep). Similar activity was reported on Monday, including a size 3 avalanche that was remotely triggered from flat terrain by a snowmobiler north of Stewart. Smaller natural avalanches were also reported on Tuesday, including size 1-2 wind slabs from recent wind loading and size 1.5-2 loose moist avalanches in steep solar-facing terrain.In addition to the ongoing persistent slab problem, the incoming weather pattern is looking to continually build fresh wind slabs.

Snowpack Summary

Fresh wind slabs are forming in the lee of exposed terrain as unsettled weather brings small amounts of new snow and moderate southwest winds. Storm snow from last week is continuing to settle and get redistributed by predominately southerly winds. Old wind slabs may be reactive above a 40 cm deep rain crust. At treeline and above, recent loading has stressed a 50-100 cm deep weak interface composed of facets, crust, and surface hoar from late February. Recent reports suggest this layer is still reactive throughout the region, especially in the north.

Regioni coperte