Avalanche Forecast
Issued: Mar 11th, 2017 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Cornices and Persistent Slabs.
stephen holeczi,
Avalanche Canada
Danger ratings over the next few days will be determined by how warm it gets in Little Yoho. Watch for exposure to cornices, and dig down to see how the storm snow/deeper weak layers are reacting.
Summary
Weather Forecast
Valley bottom temperatures will go above 0C Sunday, with alpine temperatures staying in -8 to -10C range with moderate W alpine winds and a few cm of snow each day through the early part of next week.
Snowpack Summary
60-70cm of storm snow this week has been reactive but is settling with the warmer temperatures. Winds at upper elevations have formed variable wind slabs and cornices, the latter being touchy Saturday. Persistent weak layers in the midpack have been gaining strength and are becoming less of a problem, especially in deeper areas close to the Wapta.
Avalanche Summary
We have had many large, deep avalanches this week, both natural and along highway control paths. Less activity was noted Saturday except for widespread cornice failures which were formed this past week.
Confidence
Problems
Wind Slabs
60-70cm of dry snow from the past week has been blown into cohesive wind slabs at higher elevations. These are losing sensitivity, but the snowpack will take a few days to fully adjust to the load.
- Be aware of the potential for wide propagations.
Aspects: North, North East, East, South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Many cornice failures observed Saturday from warming temperatures. Some of these were pulling out slabs below to cause larger avalanches. Expect the same for Sunday.
- Extra caution needed around cornices with current conditions.
Aspects: North, North East, East, South East, South.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
Several buried weak layers in the middle of the snowpack are gaining strength over time as they become bridged, especially in the deeper areas closer to the Wapta. Dig down to see if they are present on your line, and how they are reacting.
- Dig down to find and test weak layers before committing to a line.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 12th, 2017 5:00PM
