Avalanche forecast

Purcells

Dec 6 – 7, 2014Avalanche Canada
View on map
Archived · expired 12 years ago

Avalanche danger

Mon
Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Open full map

Highlights

New wind slabs may be a concern in exposed terrain. Persistent slabs remain a concern anywhere that did not avalanche last week.  If you observe any new activity, please send us an email at [email protected]

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3
    New snow and moderate winds have likely created wind slabs in leeward features in wind exposed terrain.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–5
    The chances of triggering a persistent slab have decreased, but the consequences are still high. Any slopes that did not avalanche during the last storm cycle should still be considered hazardous.

Confidence

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

Weather Forecast

A weak ridge of high pressure will bring dry conditions and some sun for Sunday. On Monday, the pattern changes to a strong SW flow which will persist for several days. Freezing levels will rise to around 1500m on Monday and as high as 2500m on Tuesday. Scattered precipitation is expected for Monday and Tuesday and alpine winds are expected to be moderate-strong from the SW.

Avalanche Summary

Avalanche activity has diminished, but it would still be possible for the weight of a person or sled to trigger a persistent slab, with big consequences.

Snowpack Summary

Surface layers consist of variable wind slabs and dry snow. Below this you may find a hard rain crust. In the Golden area this crust exists up to around 1600m, whereas in the south it is up to 2000m or higher. In total, last week's storm produced slabs up to 1m thick in the north of the region and around 60cm thick in the south. This slab sits on the mid-November weak layer (surface hoar, facets, and/or a crust). Below this you will likely find a 15-20cm thick layer of sugary facets, which is sitting on a solid rain crust from early November. The reactivity of these layers may be slowly diminishing, but they still warrant cautious consideration. Snowpack tests are getting hard pops and drops results, indicating the potential for large propagation and large avalanches.

Regions covered