Avalanche forecast

Purcells

Jan 7 – 8, 2012Avalanche Canada
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Archived · expired 15 years ago

Avalanche danger

Mon
Tue
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    2–5
    Windslabs have developed in the alpine and at treeline due to very strong southwest winds and warm temperatures during recent storms.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    3–7
    This is the deeper slab problem that developed during the long dry spell in early December. While this weakness has become more stubborn, avalanches that release at this layer will be very large and destructive.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    2–5
    A slab has developed during recent stormy weather that is above a weak surface hoar layer that developed over a short period of clear weather at New Year's. This slab in itself may produce avalanches up to size 3.0

Avalanche Summary

A few natural avalanches in the alpine to size 1.5 were reported from the region Friday. A skier was purportedly killed in an avalanche in the Molar area of the Dogtooth range near Golden on Friday, no details have been confirmed as of the writing of this forecast.

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

A polar warm front stalling north & west of the region will bring moderate to heavy precipitation to the surrounding areas Sunday. However, the Purcells will largely be "protected" from the action by a lingering ridge of high pressure. I expect scattered flurries in the region Sunday with snow amounts in the 5 - 10 cm range. Freezing levels rise to 1500m or so Sunday as the warm front affects the area. The trailing cold front associated with the system moves in late Sunday/early Monday bringing lower freezing levels and delivering another 5 -15 cm of snow. Expect strong SW winds at & above treeline Sunday with a daytime high of 0 C @ 1500 m.

Snowpack Summary

The latest batch of storms has delivered around 50 cm of snow to the region. In some locations the new snow rests on top of a surface hoar layer buried January 3rd. Strong southwesterly winds have redistributed the new snow into windslabs that can be found on NW through SE facing slopes at and above treeline. Widespread crossloading is present throughout the region. A rain / melt/freeze crust formed by recent warm temperatures can be found as high as 1500m. The mid-December surface hoar layer continues to be a player, it's now buried 80 - 140 cm below the snow surface. Very weak snow near the ground is also a concern and while it has not been reactive recently, triggering a full depth avalanche near the ground is within the realm of possibilities right now.

Regions covered