Avalanche forecast

Northwest Coastal

Jan 20 – 21, 2015Avalanche Canada
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Avalanche danger

Thu
Fri
Alpine
4 · High
Treeline
4 · High
Below
3 · Considerable
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Highlights

Stormy weather will maintain elevated avalanche danger this week.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    2–5
    It looks like a very wet and windy week. Expect deep wind slabs and fresh cornices to build in expose lee terrain. These may release naturally during periods of heavy loading.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–4
    Periods of heavy snowfall could create fresh touchy storm slabs in sheltered terrain. Warming and rain could trigger wet slabs or loose wet sluffs at lower elevations.

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Synopsis: It looks like we’re in for a wet and stormy week! Precipitation amounts: Tonight and Weds = 20-40 mm, Thursday = 20-30 mm, Friday = possible even heavier amounts. Freezing levels should rise to 1500 m on Wednesday and gradually climb closer to 2000 m by Friday. Winds should be generally strong from the SW throughout the week.

Avalanche Summary

Recent observations include several one natural size 2.5 wind slab from a large cross-loaded alpine slope, and several size 1-1.5 intentionally skier triggered slabs on steep wind loaded rolls. Avalanche activity will be on the rise over the next few days with incoming snow/rain, wind, and warming.

Snowpack Summary

Around 30-50 cm of recent storm snow has fallen in the past couple days, with much more expected this week. The new snow was relatively light initially but we may see heavier moist snow fall as temperatures start to rise, leaving us with an 'upside down' slab situation. Recent moderate or strong SW winds have created dense wind slabs in lee and cross-loaded terrain. A buried rain crust and/or surface hoar layer is down about 50-60 cm. Observations of the strength at this interface have been limited. The November crust near the bottom of the snowpack is generally well bonded, but may still be reactive in areas with a shallow snowpack, or with a very heavy load.

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