Avalanche Forecast

Issued: Mar 5th, 2014 7:46AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Persistent Slabs and Wind Slabs.

Avalanche Canada Peter, Avalanche Canada

Stormy weather is on the horizon! Weather models aren't in total agreement on how much snow will fall on Friday, but somewhere in the ballpark of 20-40 cm is a good guess. Either way, avalanche danger is on the rise.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Thursday: Mainly cloudy with a chance of flurries – around 5 cm. The freezing level is at the surface. Ridge winds are light to moderate from the S-SW. Friday: Moderate to heavy snowfall – 20-40 cm (heaviest along the coast). The freezing level climbs to 1200 m in the south and 500 m in the north. Winds are strong from the SW. Saturday: Moderate precipitation. The freezing level is between 1000 and 1500 m. Winds are moderate to strong from the SW.

Avalanche Summary

A few natural slab avalanches up to size 2.5 from solar aspects were reported in the northern part of the region on Tuesday. There's finally a weather change on the horizon! Expect conditions to start changing quickly on Friday and through the weekend.

Snowpack Summary

Persistent strong outflow winds (from the northeast-southeast) have scoured windward slopes and created hard or dense wind slabs in exposed lee and cross-loaded terrain. Cold clear weather has also promoted surface hoar growth and surface faceting on shady slopes and a sun crust on steep solar aspects. The mid February weak layer of surface hoar or a crust/facet combo is buried 30-90 cm deep. There has been no reported activity on this layer recently, but watch for it to wake up when the weather pattern shifts to moist and mild heading into the weekend. Basal facets and/or depth hoar remain a concern in shallow snowpack areas in the northern part of the region.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Triggering the mid February persistent weakness is unlikely until the weather changes (Friday!). Caution is still recommended on higher north aspects. 
Whumpfing is direct evidence of a buried instability.>Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Wind Slabs

An icon showing Wind Slabs
Strong easterly outflow winds continue to scour windward slopes and create hard wind slabs in areas that still have snow available for transport.
Avoid travelling in areas that have been reverse loaded by winds.>Watch for areas of hard wind slab in steep alpine features.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Mar 6th, 2014 2:00PM