Avalanche Forecast
Issued: Mar 14th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Cornices and Deep Persistent Slabs.
swerner,
Avalanche Canada
Storm slabs may continue to be reactive on Wednesday, especially on leeward wind-loaded slopes. Use conservative decision-making if you notice signs of instability.The March sun packs a punch and can quickly destabilize the snowpack on solar slopes.
Summary
Confidence
Avalanche Summary
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.
On Saturday there were reports of two wind slab avalanches. One was triggered by a rider and the other one went naturally. These occurred in the alpine on north to northeast aspects and at a depth of 20 to 25 cm.
Natural avalanche activity may occur throughout the week with rising freezing levels and solar radiation. Wind slabs may continue to be reactive to rider triggering.
Snowpack Summary
30 to 50 cm of storm snow has blanketed the region since last Friday. Much of this has been redistributed into reactive wind slabs at treeline and above. It has also built upon the large cornices that have already formed. A sun crust may exist below this new snow on steep solar aspects. In sheltered areas, this new snow will rest on various amounts of low-density snow that fell earlier in the week.
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
Tuesday Night
Cloudy, 3 cm of new snow. Alpine temperatures near -11. Winds southwest 20 to 45 km/h, with the freezing level at valley bottom.
Wednesday
A mix of sun and cloud. Alpine temperatures near -9. Winds southwest 15 to 40 km/hr gusts. Freezing level at valley bottom.
Thursday
A mix of sun and cloud. Alpine temperatures near -5. Wind light from the southeast. Freezing level 1500 m.
Friday
A mix of sun and cloud. Winds 10-20 km/hr from the southeast. Alpine temperatures near -2 with freezing levels 1800 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
Problems
Storm Slabs
30 to 50 cm of new snow and strong south wind have formed reactive storm slabs. These slabs may have a poor bond to the underlying crust.
Moderate to strong southwest winds may have formed new wind slabs on lee slopes at treeline and above.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices are large and fragile. Solar radiation and wind will weaken them further and cornice failures act as heavy triggers on slopes below.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
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 15th, 2023 4:00PM
