Avalanche Forecast
Issued: Mar 15th, 2023 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.
swerner,
Avalanche Canada
Rising freezing levels and the strong March sun can pack a punch and quickly destabilize the snowpack. Natural and human-triggered avalanches are likely.
Summary
Confidence
Moderate
Avalanche Summary
On Tuesday, natural and skier-triggered dry loose avalanches up to size 1 were reported from the North Shore mountains.
On Monday, natural dry loose avalanches were reported from steep terrain features and explosive control initiated several storm slabs up to size 1. The storm slabs were 5 to 20 cm thick with very limited propagation and entrainment.
On Sunday, a skier-triggered size 2 wind slab was reported as a MIN (check it out here) the skier was knocked off their feet but able to ski out with no injuries. A natural size one wind slab avalanche was reported in the Sky Pilot. This was in the alpine on an east aspect.
Natural and human-triggered avalanche activity will likely occur throughout the week with rising freezing levels and solar radiation.
Snowpack Summary
Surface snow will likely become moist during the day with warming and solar radiation. The recent 40 cm of storm snow is generally settling but may not have a good bond to the underlying sun crust on solar aspects and melt-freeze crust at lower elevations. Southerly winds have also created wind slabs in exposed terrain at higher elevations.
In general, the mid and lower snowpack is well-settled and bonded.
Weather Summary
Wednesday Night
Clear with some cloudy periods. Treeline temperatures near -1. Wind light 15 km/hr and freezing level valley bottom. 3-5 cm of new snow.
Thursday
A mix of sun. Treeline temperatures near +3. Winds southeast 10-20 km/hr. Freezing level 1400 m. l
Friday
A mix of sun and cloud. Treeline temperatures near +3. Wind southeast 10-20 km/hr. Freezing level 1500 m.
Saturday
A mix of sun and cloud. Winds 10-20 km/hr from the southeast. Treeline temperatures near +4 with freezing levels 1700 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
- Avoid exposure to steep, sun exposed slopes, especially when the solar radiation is strong.
- As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Storm Slabs
Storm slabs may continue to be reactive to human triggering, especially where they sit above a hard crust. Strong southwest wind may build pockets of wind slab on lee slopes at upper elevations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Wet
Strong solar radiation and rising freezing levels may weaken the surface snow creating wet loose avalanches on all aspects below 1300 m and steep solar slopes above.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Large looming cornices exist along ridgelines. Cornices become weak with daytime warming and sun exposure. Give cornices a wide berth while traveling ridgelines and avoid slopes below them.
Aspects: North, North East, East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 16th, 2023 4:00PM
