Avalanche Forecast

Moderate - Uncertainty is due to how the snowpack will react to the forecast weather.

TUESDAY NIGHT: Clearing skies, light wind from the northwest, treeline temperatures drop to -8 C.

WEDNESDAY: Clear skies except for a possibility of valley cloud, light wind from the west, a weak inversion forms with freezing level reaching 2000 m.

THURSDAY: Clear skies except for a possibility of valley cloud, moderate wind from the southwest, freezing level around 1500 m.

FRIDAY: Storm arrives with cloudy skies and 5-15 cm of snow, strong wind from the south, freezing level around 500 m with treeline temperatures around -3 C.

Over the weekend, there were a few human-triggered slab avalanches in the southern part of the region around Terrace. A few of these include size 1-1.5 persistent slab avalanches that occurred on a 30-50 cm deep surface hoar layer at treeline elevations. The photos of the avalanche in this MIN report at Clague are good examples of the type of terrain this problem was found. We are uncertain whether the persistent slab above the surface hoar layer will remain reactive after the recent melt-freeze cycle.

Warm sunny weather on Monday resulted in some small loose wet avalanches, and we expect to see similar activity on Wednesday.

The snow surface is undergoing a spring-like melt-refreeze pattern. Warm sunny weather on Wednesday will likely melt the surface in most places except high north-facing terrain. The snowpack is likely capped by a hard crust in most areas, which has helped create a strong settled snowpack. The exception is a 30-50 cm deep surface hoar layer that could still be reactive. This layer has been reported at treeline elevations in the Terrace area.

• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
• Back off slopes as the surface becomes moist or wet with rising temperatures.
• When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.