Avalanche Forecast

Low - Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack. Uncertainty is due to rapidly fluctuating freezing levels.

A major warming event is forecast for Thursday with freezing levels climbing to at least 2500 m. A storm system is expected to arrive Thursday night which will replace the warm air and linger into Friday morning. 

Wednesday Night: Mainly cloudy, light to moderate SW wind, freezing level climbing to around 1800 m. 

Thursday: Mainly cloudy in the morning, a mix of sun and cloud in the afternoon, moderate to strong SW wind, freezing level high near 2700 m.

Thursday night: Precipitation 20-50 mm, strong SW wind, freezing level 2000 m dropping to around 1200 m.

Friday: Snowfall 5-10 cm in the morning, sunny breaks in the afternoon, moderate SW wind, freezing level high around 1500 m.

Saturday: Mainly cloudy with sunny breaks, light to moderate W wind, freezing level high around 800 m.

On Tuesday, skiers triggered a few avalanches including a size 1.5 storm slab on a steep west aspect at 2000 m, a size 1 avalanche in a steep north aspect couloir at 2150 m, and a remotely triggered size 2 storm slab from 2 m away. A ski cut triggered a size 1.5 cornice release on a northwest aspect at 1900 m. Explosives triggered numerous size 1-2.5 storm slabs and cornices up to size 2.5. The storm slabs were typically up to around 60 cm thick and many were sliding on the underlying melt-freeze crust. Several of the cornice releases triggered slabs on the slopes below. 

A variety of older avalanches were also reported on Tuesday which had occurred during the storm including evidence of a natural size 2 storm slab cycle. A natural cornice release was observed which triggered a size 3 storm slab and a few other natural cornice releases which triggered size 2 storm slabs.

The recent storm produced 60-80 cm of new snow in the Whistler area. This storm snow has buried a firm crust which extends to mountain top on solar aspects and to around 2200 m on northerly aspects. This crust has been the sliding surface for many of the recent storm slab avalanches. Strong to extreme southwest wind has redistributed the new storm snow in exposed, high elevation terrain forming wind slabs up to 150 cm thick and developing large cornices. Windward slopes have been scoured down to the crust and the alpine snow surface is expected to be highly variable. A new sun crust was reported to be forming on the snow surface on Tuesday. 

The middle and lower snowpack are generally strong and well bonded. 

• Watch for changing conditions today, storm slabs may become increasingly reactive.
• The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.
• Remember that in the spring strong solar radiation and warm temperatures can weaken the snow in a matter of minutes.
• Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.