Avalanche forecast

Northwest Coastal

Apr 23 – 24, 2014Avalanche Canada
View on map
Archived · expired 12 years ago

Avalanche danger

Fri
Sat
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
Open full map

Highlights

Due to a lack of field observations, we are starting to transition to bulletins without Danger Ratings. Check out this Blog Post for more information on spring ratings.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3
    Recent wind slabs have become more stubborn to trigger, but may persist for a few more days.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–2
    Snow may become moist or wet at lower elevations due to day time warming or from exposure to the sun.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    3–7
    Deeply buried persistent weak layers continue to be  a concern for isolated hard to predict avalanches. Avalanches releasing on these deep layers may be more likely during periods of strong solar radiation, or when there is no overnight freeze.

Confidence

Fair - Timing or intensity of solar radiation is uncertain on Thursday

Weather Forecast

Overnight and Thursday: Overnight freezing levels dropping down to 1000 metres and then rising up to 1500 metres during the day. Periods of broken skies overnight, and then mostly cloudy with light precipitation during the day. Winds light to moderate from the Southeast.Friday: Cloudy with light precipitation and not much overnight freezing. Winds light from the Southeast. Saturday: Winds becoming strong Southerly. Mostly cloudy with moderate precipitation falling as snow above 1000 metres.

Avalanche Summary

We received a report of a very large natural deep-slab avalanche east of Terrace on Monday. This avalanche occurred on a NW aspect at 1800m. The crown appears to be 1-2m deep meaning it likely released on the early-Feb weak layer. We are no longer receiving professional daily reports for the region so public observations are really appreciated right now. If you are out in the mountains, send your observations to [email protected]

Snowpack Summary

Highly variable spring conditions are being reported in the region. At lower below-treeline elevations the snowpack is typically wet and isothermal. It has not been refreezing overnight and is melting quickly. Between roughly 1000 and 1500m, the snowpack has been undergoing daily melt-freeze cycles. The same conditions can be expected on sun-exposed slopes all the way to mountain-top. On higher elevation north-facing slopes, dry snow likely still exists. Recent strong S through W winds have scoured windward slopes and created wind slabs in leeward slopes. The early February crust/facet layer is typically down 1.5 to 2.5m. A smaller avalanche or a cornice fall may still have the potential to step down to this layer causing very large, destructive avalanches, especially during warm sunny periods.

Regions covered