Avalanche Forecast
Issued: Mar 7th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
MBender,
Avalanche Canada
Wind slabs at upper elevations are the main concern. Spotty flurries may develop overnight Sunday where parts of the region may receive 10 cm+ and other parts just trace amounts.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain.
Weather Forecast
SUNDAY Night: Cloudy with scattered flurries, accumulation 3-8 cm. Light to moderate west wind. Alpine high temperatures around -9 C. Freezing level at valley bottom.
MONDAY: Mix of sun and cloud. Light west and southwest wind. Alpine high temperature -6. Freezing level 1400 m.
TUESDAY: A mix of sun and cloud. Light variable wind. Alpine high temperature -5. Freezing level 1500 m.
WEDNESDAY: Cloudy with isolated flurries. Light to moderate northwest wind. Alpine high temperature -6. Freezing level 1300 m.
Avalanche Summary
On Saturday there were a few reports of storm and wind slab avalanche activity to size 1.5 and 2. These were primarily on north and northeast aspects above 2200 m.
Reports from Friday were a mix of small (size 1.5) new skier triggered wind slabs (northeast aspect) and additional observations of natural activity from the warming event the day prior. A size 3 natural wind slab release in the Monashees south of Revelstoke stands out in these reports.
On Thursday there was a fatal avalanche between New Denver and Kaslo where a snowmobiler triggered a size 3 persistent slab avalanche on a west aspect at 2400 m. The avalanche likely failed on the late January weak layer (see the Incident Report here). This avalanche problem has become less reactive as cooling temperatures have helped stabilize the snowpack.
Snowpack Summary
15-20 cm of new snow from Friday night accumulated above moist and crusty interfaces that formed during the recent warm up. Some deeper accumulations can be expected in lee terrain features. High, shaded terrain will have a mix of soft snow and some old buried wind slabs.Â
The lower snowpack has strengthened over the past week as previous persistent weak layers have become mostly unreactive. The main layers that we had been tracking are a layer of facets that was buried in mid-February (50-100 cm deep) and a layer of surface hoar and/or crusts that was buried in late January (80-120 cm deep).
Terrain and Travel
- Be careful as you transition into wind affected terrain.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
Problems
Wind Slabs
Recent new snow and wind has formed new wind slabs at upper elevations.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 8th, 2021 4:00PM
