Avalanche forecast

Purcells

Nov 25 – 26, 2014Avalanche Canada
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Archived · expired 12 years ago

Avalanche danger

Thu
Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate

Highlights

Stormy weather will drive avalanche danger up this week. It's a good time for riding low angle slopes and avoiding overhead exposure.

Avalanche problems

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3
    Be cautious of loose sluffing from steep terrain as new snowfall continues. Rain on Thursday may result in loose wet avalanches at lower elevations.
  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    2–5
    The developing storm slab sits on a touchy weak layer and is expected to become very reactive with additional storm loading. Recent wind loading has created wind slabs in leeward features which are expected to be very touchy.

Confidence

Poor - Due to the number of field observations

Weather Forecast

A warm front will move over the southern part of the province midday Wednesday resulting in mild temperatures and moderate to heavy precipitation. This will persist through Thursday before an Arctic front pushes down from the north on Friday. There is some uncertainty regarding freezing level extents and as a result the Northern Purcells may not see the warmer temperatures.Tues. Night/Wednesday: Precipitation 8-12mm, freezing levels starting at valley bottom rising to around 1500m late-Wednesday, ridgetop wind light-moderate SW-WWeds. Night: Precipitation 8-12mm, ridgetop wind moderate SWThursday: Precipitation 10-20mm, freezing levels rising as high as 2000m, possibly lower in the north, ridgetop wind strong SWFriday: A mix of sun and cloud, snow flurries possible, freezing level valley bottom, ridgetop wind light variable

Avalanche Summary

Currently there are no recent avalanche reports. It's likely that there is enough snow at higher elevations for avalanches, particularly in wind loaded alpine features. Stay alert to changing conditions and signs of unstable snow like recent avalanches, significant loading by wind or snowfall, whumpfing or cracking, or rapid warming.

Snowpack Summary

This is an estimate of what the snowpack may look like based of a few observations and previous weather. If you plan on riding in avalanche terrain be sure to supplement this with your own observations and please pass along any data you collect ([email protected]).Around 30-40 cm of recent storm snow has fallen in the past few days. This new snow may be sitting on a layer of surface hoar and/or a sun crust (similar to the South Columbia). Below this you will likely find a 15-25cm thick layer of sugary facets, which is sitting on a solid rain crust from early November. Recent strong and variable winds may have created dense wind slabs in exposed terrain. The average treeline snowpack depth is around 60-100cm. The snow probably tapers off pretty quickly as you drop below treeline. Watch out for exposed (or lightly buried) obstacles like stumps, rocks, logs, and open creeks.

Regions covered