Avalanche Forecast
Issued: Apr 6th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Loose Wet and Cornices.
rbuhler,
Avalanche Canada
Major warming with periods of strong spring sun are expected to create dangerous avalanche conditions on Thursday and a natural avalanche cycle is possible in the afternoon.
Check out this new blog post for examples of avalanche activity we may see Thursday.
Summary
Confidence
Low - Uncertainty is due to the limited number of field observations. Uncertainty is due to rapidly fluctuating freezing levels. Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.
Weather Forecast
A major warming event is forecast for Thursday with freezing levels climbing to around 2800 m. A storm system is expected to arrive Thursday night which will replace the warm air and linger into Friday morning.Â
Wednesday Night: Mainly cloudy, moderate SW wind, freezing level climbing to around 2000 m.Â
Thursday: Mainly cloudy in the morning, a mix of sun and cloud in the afternoon, moderate to strong SW wind, freezing level high around 2800 m.
Thursday night: Precipitation 30-50 mm, strong to extreme SW wind, freezing level 2500 m dropping to around 1200 m.
Friday: Snowfall 10-15 cm in the morning, sunny breaks in the afternoon, moderate SW wind, freezing level high around 1300 m.
Saturday: A mix of sun and cloud, moderate W wind, freezing level high around 800 m.
Avalanche Summary
On Tuesday, widespread size 1 wet loose avalanches were observed in the afternoon. This MIN report describes a size 2.5 storm slab which had occurred during the storm and is visible from the highway.Â
Observations are very limited this time of year. If you are getting out in the backcountry, please consider sharing your observations to the Mountain Information Network.Â
Snowpack Summary
The recent storm appears to have produced around 40-50 cm of new snow for the North Shore mountains and 70-90 cm closer to Squamish. This storm snow has buried a widespread, supportive melt-freeze crust. In the North Shore mountains, a breakable crust formed during the middle of the storm which now sits in the middle of the recent storm snow. Strong southwest wind has likely redistributed this new snow in exposed, high-elevation terrain forming touchy wind slabs and likely developing large cornices. Â
Terrain and Travel
- 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.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Storm Slabs
The recent storm snow is expected to settle rapidly with major warming and periods of sun on Thursday. This may result in the formation of a more cohesive and reactive storm slab, and natural storm slab avalanches are possible in the afternoon.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Wet
Loose wet avalanches are likely on steep slopes during Thursday's warming, especially with extended periods of sun exposure.
Aspects: South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices have grown large during the recent storm and are expected to become weak during Thursday's warming, especially with extended exposure to the sun. Falling cornices are a likely trigger for slab avalanches on the slopes below.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 7th, 2022 4:00PM
