Sea To Sky

Heavy loading from snow and wind is driving avalanche danger up.

Moderate - Timing, track, or intensity of incoming weather system is uncertain

THURSDAY: Flurries, accumulations 10-15cm, strong becoming moderate southwest winds, freezing level around 1300m.FRIDAY: Mainly cloudy with scattered flurries bringing up to 5 cm, light westerly wind and freezing level around 1200m.SATURDAY: Mainly cloudy with scattered flurries bringing up to 5 cm, light westerly wind and freezing level around 1200m.More details can be found on the Mountain Weather Forecast.

Observations are still limited by the inclement weather, but reports of widespread storm slab avalanche activity are trickling in. In the southern part of the region, reports from Tuesday include stubborn soft storm slabs triggered with explosives and ski-cutting at alpine elevations, with just snowballing at treeline and below. However, reports from the northern part of the region on Tuesday include widespread natural and explosive-triggered storm slab avalanches up to Size 2.5 well below treeline.

Rapid snow, wind and rain loading continues with fluctuating freezing levels. By Wednesday morning freezing levels had dropped, and another 30 cm or more of new snow fell as low as treeline elevations, with extreme southerly winds in the alpine. On Monday into Tuesday we had rain up to 2200m near Whistler, while in other zones like the upper Callaghan it was 35 cm or more of fresh snow. The rain (or snow high in the alpine) started to saturate and load a wide variety of previous surface conditions. Simply put, the upper snowpack is extremely variable: Last week we had very touchy wind slabs (5-40 cm thick) forming on southerly slopes near ridge crests and roll-overs. These slabs were the primary weakness of concern in the snowpack, giving easy sudden planar results in snowpack tests. Deeper in the snowpack, older snow is bonding fairly well to a variable surface consisting of a mix of soft wind slabs, hard wind slabs, sastrugi, faceted snow, and even some surface hoar. Snowpack layers below this interface are generally well bonded, and the lower snowpack is solid.