Avalanche Forecast

Moderate - Freezing levels are uncertain

One last blast of Pacific moisture is set to clash with the Arctic air mass over the province as a low pressure system moves towards the Lower Mainland late Friday. As was the case with Thursday's storm, alpine precipitation will fall as snow with only the North Shore Mountains at risk of seeing some liquid precipitation creeping up the slopes as warm air associated with the low just clips the Lower Mainland.FRIDAY NIGHT: Freezing level likely holding near 1000 m, lowering to about 400 m by Saturday morning. 25 to 35 mm of moisture expected which should fall as rather wet snow for most of the North Shore Mountains. Strong south wind. SATURDAY: Overcast, skies clearing late in the day, freezing level around 400 m, moderate NW wind, trace of snow possible.SUNDAY: Clear skies, freezing level at sea level, light variable wind, no snow expected.MONDAY: Clear skies, freezing level at sea level, light variable wind, no snow expected.

On Thursday skiers intentionally triggered avalanches on northwest trough southeast facing slopes to size 1.5. Crowns averaged 20 to 30 cm in depth and up to 90 m in width. Ski tourers noted shooting cracks on unsupported slopes while touring near the Lions. They also reported natural avalanches from the steep slopes below the Lions. Heavy snow and potentially rain Friday night accompanied by strong southerly winds will likely initiate a natural avalanche cycle that is expected to taper off by Saturday morning.

Thursday's storm produced 30 to 55 cm of storm snow. The new snow is reportedly upside down, meaning that wet heavy snow sits over light fluffy (lower density) snow. The storm snow covers a medley of old surfaces which include stubborn old wind slabs and wind scoured crusts in the alpine, and soft unconsolidated snow in sheltered areas at treeline and below.30 to 90 cm below the surface you'll likely find a couple of melt-freeze crusts which were buried mid-December. These layers may come to life as continued snowfall adds to the load. This would be most likely to occur in areas where loose facets exist above the crust.Below this, the snowpack is thought to be strong and well settled. The snowpack depth is about 160 cm at 1000 m, with many early season hazards present at lower elevations.