Avalanche Forecast

Issued: Nov 25th, 2015 8:15AM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Wind Slabs and Loose Wet.

Avalanche Canada swerner, Avalanche Canada

The snowpack is extremely variable depending on aspect and elevation and does not adjust well to rapid change. Watch for rising alpine temperatures to well above zero. Check out the Mountain Information Network. Give info, get info!

Summary

Weather Forecast

The high pressure ridge continues to dominate the coastal regions. Strong alpine temperature inversions will be prominent and freezing levels will be rising to 2400 m. Moderate to strong outflow winds will prevail in coastal valleys especially in the overnight and early morning. Valley cloud may accompany the strengthening temperature inversion. By Sunday the weather pattern may see a change, however; timing and intensity of the next Pacific system is hard to pin point due to disagreement between the Canadian model and the GFS.

Avalanche Summary

No new avalanches have been reported. This may speak to a lack of observations rather than actual conditions. Newly formed wind slabs may remain sensitive to human triggering and surface snow may start to deteriorate especially on solar aspects with the warming. Watch for obvious clues of instability like natural avalanches, snow balling and moist/ wet snow.

Snowpack Summary

Mondays 10-20 cm of new snow has seen some serious effects from the recent winds and cold temps. Northerly winds have likely built stiff wind slabs on southerly slopes and stripped snow from exposed aspects. These wind slabs may have a poor bond to the old surfaces that comprise of surface hoar, crusts (potentially up to 2100 m) and some dry facetted snow above that. Strengthening temperature inversions at upper elevations may start to deteriorate the upper snowpack, especially on southerly aspects. Watch for obvious signs of instability like moist and/or wet snow surfaces and snow balling. Where the buried crust is thick, avalanches failing on deeper layers beneath have become much less likely. My uncertainty lies at higher elevations where the buried crust doesn't exist and deeper persistent weak layers may. Reports indicate that these shears are resistant and in the moderate to hard range, however; I'd remain extra cautious and have an investigative approach while traveling, as they may continue to be sensitive to rider triggering.

Problems

Wind Slabs

An icon showing Wind Slabs
Stiff wind slabs, especially on southerly aspects will likely have a poor bond to the old snow surfaces and may remain sensitive to rider triggers.
Be cautious as you transition into wind affected terrain.>Start on mellow slopes and use a cautious approach to terrain while gathering information along the way.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Loose Wet

An icon showing Loose Wet
Strengthening warm air aloft (above 1000 m) may deteriorate snow surfaces initiating loose wet avalanches. Smaller avalanches could dig down to deeper layers, especially at higher elevations, initiating larger slab avalanches.
With these very warm temperature inversions, use extra caution, on or near sunny slopes above treeline.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Nov 26th, 2015 2:00PM