Avalanche Forecast
Issued: Apr 3rd, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Deep Persistent Slabs.
bchristie,
Avalanche Canada
The danger ratings below represent areas that see cloudy skies, and little to no new snow on Tuesday. Dynamic spring weather could bring you intense sun or snowfall, either of which would increase the avalanche danger.
Observe your local conditions and let that inform your terrain choices.
Summary
Confidence
Avalanche Summary
No notable avalanches were reported before 4pm on Monday.
On Sunday, around the forecast area, the new snow was reported to be reactive to rider traffic. Numerous small to large (size 1-2), rider triggered avalanches were reported, all in the alpine, and mostly on northeast aspects.
Several reports mentioned that the storm snow was touchy, propagated easily, and had the potential for remote and sympathetic avalanches.
This Mountain Information Network (MIN) post describes a skier triggered avalanche near the far south end of the forecast area.
Snowpack Summary
Recent convective weather has resulted in variable snowfall amounts across the forecast area.
15-40 cm of mostly soft snow is settling over a widespread, thin crust except north facing slopes at treeline and above, where it sits on old, faceted surfaces, and surface hoar in some areas.
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. This layer remains a concern in rocky, shallow, or thin to thick snowpack areas at treeline and above.
Weather Summary
A generally convective weather pattern will mean that on Tuesday we'll see spotty areas of cloud and light snowfall, or quick bursts of intense snowfall, but it also might be sunny, and everything could change at the drop of a hat. Most notably, the eastern edge of the South Selkirks (East of Nakusp and Slocan), have the highest potential for sustained convective snowfall Monday night/Tuesday, and could see up to 20 cm of new snow.
Monday Night
Mix of clear and cloud. Possible trace of snow expected. Light variable ridgetop wind. Freezing level falling to valley bottom. Treeline low around -8°C.
Tuesday
Mostly cloudy. Possible trace of snow expected. Up to 20cm in isolated areas, see note above. Light variable ridgetop wind. Freezing level rising to around 1400m. Treeline high around -5°C.
Wednesday
Mix of sun and cloud. No new snow expected. Light west or southwest ridgetop wind, trending to moderate at higher elevations. Freezing level at valley bottom overnight, rising to around 1500m.
Thursday
Mostly cloudy. 0-2 cm of snow expected. Light to moderate southeast ridgetop wind, trending to strong southwest at higher elevations. Freezing level at valley bottom overnight, rising to around 1600m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Even a small avalanche can be harmful if it pushes you into an obstacle or a terrain trap.
- Pay attention to isolated alpine features as well as cross-loaded features at treeline.
- Make observations and assess conditions continually as you travel.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Problems
Storm Slabs
The weekend's storm brought 15-20 cm of new snow to most of the region, with isolated areas getting 30-40cm. Spotty spring squalls mean these storm slabs may remain reactive in some areas, while in other places, the recent snow has already settled and bonded.
Most notably, the eastern edge of the South Selkirks (East of Nakusp and Slocan), have the highest potential for sustained convective snowfall Monday night/Tuesday, and could see up to 20 cm of new snow and higher avalanche danger.
Moderate southwest wind may have formed deeper, more reactive deposits of snow on leeward slopes.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
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. 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: Apr 4th, 2023 4:00PM
