Avalanche Forecast

Unsettled weather continues with light snowfall. Heavier snowfall is forecasted for the immediate coast and further up some inlets, but it is looking unlikely that it will push very far inland.

FRIDAY NIGHT: Mostly cloudy. 3-8 cm of snow expected. Moderate southwest ridgetop wind. Freezing level falls to around 500 m. Alpine low around -6 °C.

SATURDAY: Partly cloudy. 0-5 cm of snow expected. Light to moderate southwest ridgetop wind. Freezing level down to 500 m overnight, and rising to 750 m through the day. Alpine high around -4 °C.

SUNDAY: Partly cloudy. 2-10 cm of snow expected. Moderate south ridgetop winds, trending to strong in the afternoon. Freezing level at valley bottom overnight, rising to 600 m through the day. 

MONDAY: Mostly cloudy. 5-10 cm of snow expected, with another trace through the day. Strong southwest ridgetop winds. Freezing level rising to 1400 m. 

On Thursday and Friday, northwest of Terrace, large to very large avalanches were being triggered by riders and vehicles. These avalanches:

• were failing on a layer of fairly large (10 mm), weak, feathery, surface hoar crystals that were buried early in March.
• were occuring mostly on Northeast facing slopes around treeline.
• were easily triggered, and propagating long distances.
• were failing 60-100 cm deep.

On Thursday, west of Terrace, where heavier snow and rainfall has continued, small, naturally triggered dry loose avalanches were reported in the high alpine, as well as a large glide slab avalanche at treeline. 

35-80cm of recent snow has fallen, with strong southwest winds creating deeper deposits on east facing aspects. Low elevations may hold 10-30 cm of wet/moist snow sitting over a widespread crust on all aspects below 1200 m.

50-100 cm below the snow surface, a weak layer of feathery surface hoar crystals could be preserved in sheltered terrain at and above treeline. This weak layer has started producing large avalanches, mostly north and west of Terrace, where moderate to heavy snowfall and wind have continued through the week. In areas further inland, where the storm tapered off earlier, this layer may not be at its tipping point, but I'd still be suspicious of it through the weekend. 

A thick rain crust from mid-February is buried 100-150 cm. The snowpack below is well consolidated.

• Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
• Start with conservative lines and watch for clues of instability.
• Be careful as you transition into wind affected terrain.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
• Surface hoar distribution is highly variable. Avoid generalizing your observations.