Avalanche Forecast

Issued: Mar 7th, 2016 8:02AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Cornices.

Avalanche Canada pmarshall, Avalanche Canada

Stormy conditions continue this week. Expect fresh soft slabs to build, especially in wind exposed terrain.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Tuesday

Weather Forecast

TUESDAY: Periods of snow – around 15 cm. The freezing level is around 800-1100 m. Ridge winds are moderate from the south. WEDNESDAY: Possible sunny breaks to start with snow developing late in the day. The freezing level could rise to 1200-1400 m. Ridge winds are light but increase to strong from the SW-SE with the arrival of the storm. THURSDAY: Cloudy with sunny breaks and a chance of flurries. The freezing level is near 1400 m and winds are light.

Avalanche Summary

Backcountry observations have been limited, likely because of inclement weather, but there were reports of a few natural and skier controlled or accidentally-triggered slab avalanches up to size 2 on Sunday. Of note, an isolated yet destructive size 3 natural persistent slab avalanche was reported late last week in the South Chilcotin area north of Goldbridge. The avalanche failed on surface hoar buried in early February. Cornices are large and fragile, and may also fail under the weight of a person.

Snowpack Summary

Storm totals from the past week were between 50-70cm with more currently falling and much more on the way this week. Previous strong southwesterly winds have shifted the new snow into deeper storm slabs on lee and cross-loaded alpine and treeline features. On all but higher elevation shaded slopes the new snow from Sunday likely overlies a melt-freeze crust from high freezing levels and sun on Saturday afternoon. Below the recent storm snow, the snowpack is generally strong and well-settled. That said, a layer of surface hoar buried at the beginning of February is a concern in the South Chilcotin area and can be found about 70cm below the surface. Although this layer is isolated, it has been responsible for destructive natural avalanche activity and is worth keeping on your radar if you're headed to the north of the region.

Problems

Storm Slabs

An icon showing Storm Slabs
Touchy storm slabs may exist, particulary in wind-loaded (NW-E aspects) terrain at treeline and in the alpine. Triggering remains likely in steep unsupported features. 
Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Be aware of the potential for wide propagations due to the presence of hard windslabs.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Cornices

An icon showing Cornices
Cornices are reported to be very large and weak. Stay well back from ridgecrests, and watch your overhead hazard.
Cornices become weak with daytime heating. >Extra caution needed around cornices with current conditions.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Mar 8th, 2016 2:00PM