Avalanche Forecast

Issued: Mar 8th, 2016 7:33AM

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

Avalanche Canada pmarshall, Avalanche Canada

Danger could rise sooner than indicated if we see more than 10 cm of new snow (with wind) before the end of the day on Wednesday.

Summary

Confidence

Moderate

Weather Forecast

WEDNESDAY: Mainly cloudy with snow developing late in the day. The freezing level should be around 1500 but will rise to 1800 m overnight. Ridge winds increase to strong or extreme from the S-SW with the arrival of the storm. THURSDAY: Periods of snow – 20-50 cm Wednesday night through Thursday. The freezing level drops to around 1400 m and winds are moderate to strong from the south. FRIDAY: Cloudy with sunny breaks. The freezing level could rise to 1800 m during the day and winds ease to light.

Avalanche Summary

Explosives control on Monday in the Northwest corner of the region produced a few size 3 slabs that released on the Feb. 11 crust. On Monday, there were also reports of widespread evidence of a large natural avalanche cycle (up to size 3) that probably occurred on Saturday or Sunday. Cornices have also been popping off with some regularity.

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. This problem will increase heading into Thursday with the arrival of the next strong weather system.
Be cautious as you transition into wind affected terrain.>Choose conservative lines and watch for clues of instability.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Cornices

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

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Mar 9th, 2016 2:00PM