Avalanche Forecast

Issued: Mar 2nd, 2017 4:26PM

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

cam_c, Avalanche Canada

South Coast Inland.

Snowfall amounts may vary throughout the region. In the Cascasdes, heavy snow is expected to result in HIGH danger, while further north, much drier conditions are expected to result in slightly lower danger.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

FRIDAY: Another 20 cm possible (Coquihalla) but dry further north (Duffy). Strong SW winds. Temperatures starting to cool a few degrees.SATURDAY: A mix of sun and cloud with scattered flurries bring as much as 5-10 cm to some areas. Freezing levels around 700 m and light southwesterly winds.SUNDAY: A mix of sun and cloud with scattered flurries bring as much as 5-10 cm to some areas. Freezing levels around 00 m and light southerly winds.

Avalanche Summary

Reports from Wednesday include several natural avalanched in steep leeward alpine terrain up to Size 2. Avalanche activity will increase with forecast snow, wind, and warming temperatures.

Snowpack Summary

Much of the region received 30-50cm of fresh snow since the weekend, which has been blown into deep drifts by southerly winds and is bonding poorly to facets and buried surface hoar, as well as crust on previously sun-exposed slopes. The widespread mid-February crust is below all this. In the northern part of the region, a facet/surface hoar weakness buried early February, is now down around a metre and remains reactive in snowpack tests. It is also suspected as the failure plane in at least one of two recent large persistent slab avalanches in the Hurley Pass area. In the Cascades (e.g. Coquihalla), the mid and lower snowpack are well settled and strong. Forecast new snow is likely to arrive with strong SW winds and warming temperatures.

Problems

Storm Slabs

Watch for wind slabs in the lee of exposed, higher elevation terrain features. Areas with higher amounts of storm snow (e.g. Coquihalla), are likely to develop more widespread storm slabs on steeper terrain features (even where wind protected).

Be cautious as you transition into wind affected terrain.Be aware of increased wind slab danger in the south of the region.Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

A pattern of persistent slab avalanche activity recently emerged in the northern part of the region. Recreating in the mountains north of Pemberton suggests using more conservative terrain with additional caution on northerly aspects.

Be aware of the potential for large avalanches due to the presence of deep weak layers.Be cautious in shallow snowpack areas where triggering is more likely.Avoid steep convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 4

Valid until: Mar 3rd, 2017 2:00PM