Avalanche Forecast
Issued: Dec 16th, 2019 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
aaron beardmore,
Parks Canada
Increased wind and small amounts of new snow are creating new reactive wind-slabs at ridge top.
Summary
Weather Forecast
Seasonal temps (-5 in the valley, -10 at the ridge) for the next few days. Light snow is expected totalling 10cm by Thursday midday. Ridgetop wind is expected to be in the strong to extreme range from the W-SW on Tuesday afternoon. Some more significant snow is expected on the weekend, but the outlook is still uncertain.
Snowpack Summary
Reactive, thin (~10cm) new windslabs are being created by increased west wind. Beneath the recent 40-60 cm of storm snow, the snowpack structure is generally weak, consisting of facets and depth hoar. The Nov crust is present up to 2500m and ~30 cm up from ground. Snowpack depths at treeline range from 80-160 cm.
Avalanche Summary
Small windslabs (size 1) were reported near Mt Ogden today. They likely occurred within the last 24 hours. Additionally, a small wind slab was triggered by 2 ice climbers on the half way ledge on Bourgeau Left today.
Confidence
Wind effect is extremely variable on Tuesday
Problems
Wind Slabs
Overnight wind transport has created thin wind slabs predominantly on East aspects directly below ridge top. Pay attention to wind values and new snow amounts that contribute to this problem over the next 24 hours.
- Use caution in lee areas. Recent wind loading has created slabs over weaker snow.
- Caution on open steep slopes at treeline that have been exposed to wind loading.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Deep Persistent Slabs
The recent snow sits over weak facet and crust layers. As time goes on the chance of triggering is becoming less likely, but there is lots of uncertainty as to where you could trigger an avalanche and what it will take to get it moving.
- Be aware of thin areas that may propogate to deeper instabilites.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 17th, 2019 4:00PM
