Avalanche Forecast
Issued: Jan 17th, 2015 4:24PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
conrad janzen,
Avalanche Canada
20-30cm of new snow is forecast to fall in the Little Yoho region by early Monday morning accompanied by strong W winds. We will see the hazard rise throughout Sunday and expect to see the peak avalanche activity late Sunday night and into Monday.
Summary
Weather Forecast
A storm is forecast to arrive by mid day on Sunday bringing 20-30cm of new snow and very strong West winds at ridge top. The winds ease off a little on Monday and switch to the NW with a few more cm`s of snow forecast for Monday and Tuesday. Treeline temperatures remain between -4 and -10`C.
Snowpack Summary
The main concern in the snowpack is the Dec 18 surface hoar layer down 40-50 cm. This layer is very prominent and is producing moderate test results and lots of whumphing. 10cm of new snow in the last 48hrs combined with the 20 - 30 expected on Sunday will likely reactivate this layer.
Avalanche Summary
No new avalanches observed or reported in last 72 hours.
Confidence
Problems
Storm Slabs
With the arrival of new snow and strong winds on Sunday we can expect to see avalanche activity start to increase as a storm slab develops over the Jan 16th surface hoar. This will be of most concern in wind loaded areas.
- Avoid freshly wind loaded features.
- Minimize exposure during periods of heavy loading from new snow, wind.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A persistent weak layer from Dec 18th of surface hoar/crust/facets lurks 40-50 cm's below the surface. This layer is most reactive at the tree line elevation where it is a surface hoar/crust combination.
- Choose conservative lines and watch for clues of instability.
- Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 18th, 2015 4:24PM
