Avalanche Forecast
Issued: Mar 23rd, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs.
trettie,
Avalanche Canada
Continue to practice good group management, High mark or ski steep terrain one at a time and minimize time below cornices.
Summary
Confidence
Avalanche Summary
Several naturally triggered wet loose avalanches up to size 2 were reported on sunny aspects in the alpine.
Two naturally triggered large (size 2-2.5) deep persistent slabs were reported on northerly aspects in the alpine on Monday. One was triggered by a cornice fall in the Renshaw zone and the other occurred in the Premier range.
Large natural cornice falls continue to be reported in this region.
Snowpack Summary
Expect the snow surface to change throughout the day. A crust will likely be found at treeline and below and on sun exposed slopes in the morning. Moist snow may be found on these same slopes by mid day. Light flurries may bring fresh dry snow to upper elevations.
Check out this MIN from our field team's visit to Renshaw.
20-30 cm down there is a sun crust on sunny aspects and surface hoar (3-10 mm) on isolated shady and sheltered slopes.
The mid-snowpack is generally strong but the lower snowpack is a different story..The November facets are still prominent at the base of the snowpack. They are showing signs of improving but this layer remains a significant concern in rocky, shallow, or thin to thick snowpack areas at treeline and above.
Weather Summary
Thursday Night
Cloudy with up to 5 cm of new snow expected. Light southerly winds and a Low of -8°C at 1800 m.
Friday
A mix of sun and cloud with the possibility of light flurries bringing around 5 cm of new snow. Light variable winds and a High of -1°C at 1800 m. Freezing level rising to 1600 m.
Saturday
Mostly cloudy with the possibility of convective flurries bringing up to 10 cm of new snow. Light westerly winds and a high of -2°C at 1800 m.
Sunday
A mix of sun and cloud with the possibility of flurries bringing up to 5 cm of new snow. Light variable winds and a high of -5°C at 1800 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- Cornice failure may trigger large avalanches.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Problems
Deep Persistent Slabs
A weak layer of facets exists near the base of the snowpack. The likelihood of human triggering is low given the layer's depth, but large triggers such as cornice failures or smaller avalanches in motion have the potential to produce very large avalanches with surprisingly wide propagation. Suspect terrain for human triggering includes steep, shallow, and rocky terrain where the snowpack transitions from thin to thick.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 24th, 2023 4:00PM
