Avalanche forecast

Northwest Inland

Mar 16 – 17, 2012Avalanche Canada
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Avalanche danger

Sun
Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–4
    Recently formed windslabs may exist on lee slopes adding to a strengthening hard wind slab problem that developed last week.

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–5
    Large cornices exist in alpine terrain. A failure could be destructive by itself, and could also trigger an avalanche on the slope below.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    3–6
    The likelihood of triggering persistent layers buried in early February is greatest on steep, unsupported terrain . Although no recent avalanches have been reported, the chances of triggering may increase with solar radiation forecast for the weekend

Confidence

Fair - Due to limited field observations

Weather Forecast

Generally settled weather with flurries possible throughout the forecast period, Saturday, Sunday and Monday. Winds generally light, initially from the southeast, becoming southerly on Sunday and Monday. Freezing levels going up to around 800 m during the day and dropping down to valley bottom each night.

Avalanche Summary

Soft slabs were reported to have been developing at treeline on Thursday. Some activity was noted outside the region to the west in recent storm snow. Nothing has been noted from this region. However, observations have been very limited.

Snowpack Summary

Moderate amounts of low density snow sit over a variety of old surfaces that include widely distributed hard wind slabs, or melt freeze crusts that exist on most aspects below 1000m and on solar aspects as high as 1600m. In exposed areas the newer snow has been shifted into deeper pockets of soft wind slab. The mid February persistent weak layer interface, comprised of spotty surface hoar, facets and crusts, is buried 80-120 cm below the surface. No recent activity has been reported on this interface. However, recent snowpack tests have been giving hard but sudden "pop" results and indicate it is has the potential to react given the right trigger in the right place. For route selection, it should still be on your radar and is most likely triggerable on steeper, unsupported terrain. Cornices in the area are reported to be very large and primed for triggering.

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