Archived

Avalanche Forecast

Mar 10th, 2016–Mar 11th, 2016

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: South Coast.

Extreme winds on Thursday and ongoing wind-loading on Friday will keep danger high in the alpine. Give all this new snow a couple days to settle before pushing out to bigger more committing terrain.

Confidence

Moderate

Weather Forecast

FRIDAY: Cloudy with a chance of sunny breaks followed by light snow 5-10 cm. The freezing level is around 1200-1400 m and winds are moderate from the south. SATURDAY: Periods of snow 20-30 cm. The freezing level is around 1200 m and winds are moderate gusting strong from the SE-SW. SUNDAY: Mainly cloudy with flurries. The freezing level hovers around 1200 m and winds ease to light.

Avalanche Summary

Expect a widespread natural avalanche cycle throughout the day on Thursday in response to rapid loading from snow and wind. We could see numerous size 2-3 storm and wind slabs, with the potential for even large slides stepping down the the early February surface hoar layer. It will be a day to wait out the storm from a safe place.

Snowpack Summary

The current snow surface consists of soft wind slabs in exposed lee terrain, dry lower density snow in sheltered terrain, and some places have mentioned small surface hoar forming overnight on Tuesday. Forecast heavy snowfall, warming, and very strong winds will rapidly create fresh storm slabs everywhere, and deep wind slabs in exposed lee terrain for Thursday. Some areas could see 50-80 cm in a 24 hour period! This intense loading could overload a weak layer of surface hoar buried at the beginning of February, and currently about 70-80 cm below the surface. This layer is primarily a concern in the South Chilcotin Mountains. Expect a widespread and large natural avalanche cycle during the storm. Ongoing stormy weather has also encouraged extensive cornice growth.

Avalanche Problems

Storm Slabs

Triggering deep fresh storm slabs remains a concern on Friday. Winds are also forecast to remain fairly strong resulting in further wind loading on northerly aspects, and the potential for natural releases.

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 2 - 5

Cornices

Cornices are reported to be massive and weak. These could pop off at any time, but are more likely to fail with continued growth or during brief sunny breaks.

Extra caution needed around cornices with current conditions.>Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 5