Avalanche Forecast

Issued: Mar 16th, 2014 9:56AM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs and Deep Persistent Slabs.

Avalanche Canada bcorrigan, Avalanche Canada

Summary

Confidence

Fair - Due to the quality of field observations

Weather Forecast

Synopsis: A low pressure system in the Gulf of Alaska will feed moisture onto the coast and into the interior for the next 4 or 5 days.Tonight: Cloudy with flurries, 5 to 10 cm of precipitation, freezing level around 200 metres winds from the west  25 to 35 Km/hr.Monday: Cloudy, trace of precipitation in the forecast, freezing level around 500 metres, winds from the west, 25 Km/hr.Tuesday: Cloudy with flurries, possible 5 to 10 cm of precipitation,, freezing level around 1000 metres winds from the south west light occasionally gusting to moderate.Wednesday: Sunny with cloudy periods and isolated flurries, 5 to 10 cm of precipitation expected, freezing level rises to around 1300 metres, winds light from the west, gusting moderate to strong.

Avalanche Summary

No reports of avalanche activity on Sunday at time of publishing, but this is more likely a result of the lack of observations rather than lack of avalanche activity. Widespread activity  has been expected for Saturday night and Sunday as the storm passes through the area..

Snowpack Summary

The recent storm snow is sitting on a a variety of weak layers that includes well-developed sun crust on solar aspects, surface hoar in sheltered areas, and a widespread temperature/rain crust at lower elevations. Strong SW storm winds are forming new wind slabs on lee slopes.The warm weather has resulted in good settlement of the snowpack and most of the layers are now well bonded. There are still two weak layers that remain a concern but these problems are becoming more isolated. However, the weight of the new storm snow may reactivate these layers. With recent storm snow loading, the March layer should now be down close to 100cm and the early February layer should be roughly 1.8m. It seems like these persistent weak layers are more of a concern in the northern parts of the region but they may still pose a threat in the Coquihalla and south and east towards Manning Park.

Problems

Storm Slabs

An icon showing Storm Slabs
Heavy snowfall and strong winds continue to build storm slabs. Expect stiff wind slabs in lee features from strong S-SW wind.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Pay attention to overhead hazards like cornices.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 4

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
There are two deep persistent weak layers of concern within the snowpack. These have been quiet recently but may wake up with the weight of the new storm snow. Smaller avalanches have the potential to overload and trigger one of these deeper layers.
Be aware of the potential for full depth avalanches due to deeply buried weak layers.>Be aware of thin areas that may propogate to deeper instabilites.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 6

Valid until: Mar 17th, 2014 2:00PM