Avalanche Forecast
Issued: Mar 3rd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet and Wind Slabs.
astclair,
Avalanche Canada
Rising temperatures may initiate wet loose avalanches and weaken cornices. Check steep or confined lines for wind slab or wet surface snow before committing and give cornices a wide berth from above and below.
Summary
Confidence
Weather Forecast
Wednesday night: Mostly cloudy, moderate to strong south wind, freezing level rising to 1400 m.
Thursday: Mostly cloudy, 5-10 mm falling as rain at lower elevations starting in the afternoon, strong south wind, freezing level near 1300 m.
Friday: Overcast, 35-55mm of precipitation overnight and throughout the day falling as rain at lower elevations, strong southwest wind, freezing level and snow line dropping from 1500 m to 1000m.
Saturday: Increasing cloud, scattered flurries with up to 5 cm of snow above 700 m, moderate south winds, freezing level near 800 m.
Avalanche Summary
On Tuesday, operators reported a small (size 1) wet loose avalanche on a south aspect. This avalanche activity is representative of what is expected given the warming temperatures and forecast precipitation on Thursday.
This MIN from Sky Pilot on Sunday describes cornice debris around 1600 m.
There have been no reports of avalanche activity over the February 24th crust layer since last Thursday, when small to large (size 1-2) skier triggered avalanches in the storm snow were reported on all aspects.
Snowpack Summary
A rise in temperature and 5-10 mm of precipitation beginning in the afternoon on Thursday is expected to increase the potential for wet loose avalanche activity on slopes experiencing warming for the first time. Watch for pinwheels and roller balls, as they are a clear indication of this problem. You can avoid them by staying off steep slopes when the snow becomes wet or slushy.
Strong south winds may contribute to wind slab formation in exposed areas above 1300 m, where precipitation may fall as snow. The combination of wind, temperature, and precipitation has the potential to weaken cornices.
30-40 cm of snow from the past week sits on top of a hard rain crust that exists all the way to the tops of the North Shore mountains. Reports indicate that the snow is adhering well to the crust.
The snowpack below the rain crust is well settled and strong in most areas. Watch North Shore Rescue's snowpack update from Friday here.
Terrain and Travel
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Extra caution for areas experiencing rapidly warming temperatures for the first time.
- The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.
- Carefully evaluate steep lines for wind slabs.
Problems
Loose Wet
Loose wet avalanches are most likely on slopes experiencing above freezing temperatures for the first time. A wet snow surface, pinwheeling, or point releases from rocks are good indicators that it is time to back off.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Wind Slabs
A modest supply of new snow has fueled the continued formation of cornices and thin but potentially reactive wind slabs on a variety of aspects.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 4th, 2021 4:00PM
