Bollettino valanghe

Northwest Coastal

Feb 18 – 19, 2020Avalanche Canada
Vedi sulla mappa
Archiviato · scaduto 7 years ago

Pericolo valanghe

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

In sintesi

Be ready to step back from sun exposed slopes in the afternoon. Storm slabs may remain reactive in deep wind loaded pockets in the alpine and where it overlies a weak layer of surface hoar crystals at treeline and below.

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible - Likely
    Dimensione
    1–2.5

    40-60 cm of new snow has accumulated over the past week. In many areas the recent snow will be on a positive stabilizing trend, but human triggered avalanches remain a serious concern. Particularly on steep slopes where the new snow is settling over crust or surface hoar layers, as well as in exposed areas where much of this snow has been transported into thick wind slabs.

Confidence

Moderate - Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.

Weather Forecast

Monday night: Scattered cloud. Light northwest wind. Freezing level valley bottom.

Tuesday: Mix of sun and cloud. Light southwest wind. Freezing level 700 m.

Wednesday: Sunny. Moderate to strong south wind. Freezing level 500 m.

Thursday: Mostly cloudy. Moderate southwest wind. Freezing level 500 m.

Avalanche Summary

Over the weekend, natural storm and wind slab avalanches size 2-2.5 were the story in the alpine. One size 3 was observed over the highway corridor and at least one size 2 storm slab was solar triggered. At treeline, human triggered storm slabs size 1-1.5 have been running on surface hoar 40 cm deep.

Snowpack Summary

40-60 cm of snow from the past week has seen some redistribution in exposed alpine areas, with soft wind slabs forming in immediate lees of ridge crests. At treeline and below, it may sit over patches of surface hoar in wind sheltered areas or crusts on solar aspects.

A thin layer of facets that formed during the January cold snap is now about 120-170 cm below the surface while an early season crust lingers at the base of the snowpack. These layers produced a few large natural avalanches in early February but have recently been unreactive.

Terrain and Travel

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Be alert to conditions that change with elevation and wind exposure.
  • Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.
  • Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet

Regioni coperte