Avalanche Forecast
Issued: Mar 16th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Cornices and Deep Persistent Slabs.
swerner,
Avalanche Canada
Hazard will rise to considerable in the alpine during peak daytime heating.Reactive wind slabs may be found on leeward wind-loaded slopes.
Summary
Confidence
Avalanche Summary
On Wednesday, dry loose natural avalanches were seen from steep terrain up to size 1.5. A skier-controlled size 1 wind slab and several natural cornice failures up to size 2 were also reported.
On Tuesday, several skier-controlled slab avalanches (size 1.5) were reported on wind-loaded features at treeline and above. Dry loose sluffing was noted from steep northeast terrain up to size 1.5.
On Monday, several natural cornice falls were reported in the northern part of the region up to size 2.5.
On Sunday, a natural large size three, wind slab avalanche was observed. It started in a cross-loaded feature in the alpine and it may have stepped down to weaker buried layers.
Natural and human-triggered avalanche activity may be seen throughout the weekend with rising freezing levels and solar radiation.
Snowpack Summary
Surface snow will likely become moist to ridgetop on solar aspects by the afternoon. Cornices loom over ridgelines and may become weak during periods of solar radiation and warming.
30 to 50 cm of recent storm snow sits above a sun crust on steep solar aspects, dryer low-density snow, and older faceted snow in sheltered areas. Much of this has been redistributed into reactive wind slabs at treeline and above.
The mid-snowpack is well consolidated.
There is a widespread weak layer of large sugary facets at the bottom of the snowpack. Recent avalanche activity on this layer has been confined to northern parts of the region in the Chilcotins. This layer remains a concern in shallow snowpack areas.
Weather Summary
Thursday Night
Clear. Alpine temperatures near -6. Wind southeast 10 km/hr and freezing level valley bottom.
Friday
A mix of sun. Alpine temperatures near -1. Winds southwest 10-30 km/hr. Freezing level 1800 m.
Saturday
A mix of sun and cloud. Alpine temperatures near 0 degrees. Wind southeast 10-30 km/hr. Freezing level 1900 m.
Sunday
Cloudy with isolated flurries. Winds 10-20 km/hr from the southeast. Alpine temperatures near +1 with freezing levels 2000 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Problems
Wind Slabs
Moderate to strong southwest winds have formed reactive wind slabs on lee slopes at treeline and above.
Strong solar radiation may weaken the surface snow creating wet loose avalanches from steep solar slopes during the heat of the day.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Cornices are large and fragile. Solar radiation will weaken them further and cornice failures act as heavy triggers on slopes below.
Aspects: North, North East, East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A layer of weak facets sits near the base of the snowpack. This layer is most likely to be problematic in steep, wind-loaded terrain where the snowpack depth varies from thick to thin. Especially in the northern part of the region around the Chilcotins, Birkenhead, and Hurley.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 17th, 2023 4:00PM
