Avalanche Forecast

Issued: Mar 6th, 2015 8:19AM

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

rbuhler, Avalanche Canada

South Rockies.

Warm air temperatures with strong afternoon sun may destabilize the upper snowpack on south-facing slopes. Use extra caution on sun exposed slopes during the afternoon.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

The ridge of high pressure continues to keep things dry and clear for the next 3 days. On Saturday, a mix of sun and cloud is expected with light-to-moderate NW winds in the alpine. Freezing levels are expected to be around 2000m. On Sunday and Monday, mainly sunny conditions are expected with light winds from the SW-NW and freezing levels around 2000m or higher.

Avalanche Summary

No new avalanches have been reported recently. Natural avalanches are generally not expected on Saturday except possibly sun-triggered sluffing on steep south-facing slopes.Â Human-triggered avalanches remain possible in isolated areas, specifically wind-loaded areas of the alpine or steep sun-exposed slopes.

Snowpack Summary

In sheltered areas, up to 10 cm of new snow from earlier in the week sits over a previously variable snow surface which was a mix of surface hoar, crusts, wind affected surfaces, and/or dry powder. Ongoing winds have redistributed the new snow in wind-exposed terrain resulting in a highly variable snow surface and the formation of thin wind slabs in leeward features. The most prominent snowpack feature is a thick supportive crust around 10-30 cm below the surface. It extends up to around 2200m elevation. Below this elevation the crust is effectively capping the snowpack, preventing riders from stressing deeper persistent weak layers. In alpine areas where the crust is not present or is less thick, it could still be possible to trigger a deep avalanche from rocky sun-exposed slopes, thin snowpack areas, or with a heavy load (i.e. cornice fall).

Problems

Persistent Slabs

Deeper weaknesses still exist and remain a concern in shallow rocky areas or anywhere the thick near-surface crust is weakening or non-existent, specially north aspects above 2200m.

Be aware of thin areas and rock outcroppings where it may be possible to initiate an avalanche that fails on one of the deeply buried weak layers.>

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

3 - 6

Wind Slabs

Recent light snowfall and moderate winds from variable directions have created pockets of thin wind slab in exposed leeward terrain features.

Be cautious as you transition into wind affected terrain.>Use ridges or ribs to avoid pockets of wind loaded snow.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Loose Wet

Warming temperatures and solar radiation may cause sluffing on steep sun exposed slopes in the afternoon.

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 7th, 2015 2:00PM