Extreme cold has helped conditions. However, a warming trend and incoming snow starting Thursday will elevate the hazard rating.
The polar vortex persists, but there is light at the end of the tunnel. A slight warming trend is starting tomorrow and valley temperatures are expected to crest at about -5 on Thursday. The incoming warming trend will bring approx 15cm by Friday morning. Throughout this period wind will be strong from the SW and then drop to light.
30-50 cm of snow since Dec 31 sits over a variety of surfaces including facets, surface hoar and sun crust. Windslabs may still exist in leeward alpine areas. In most areas there is a settled mid-pack over top of weaker basal layers.
Sunshine Patrol heard to large audible avalanches in the Delerium Dive area which were cornice triggered this afternoon. No other avalanches observed or reported.
Wind slabs still exist in the alpine and at treeline elevations from incremental snow fall and wind. Pay attention at the local level for new wind slab development.
- Use caution in lee areas. Recent wind loading has created reactive slabs.
Aspects:North, North East, East, South East, South, North West.
This layer may present as surface hoar / facets / or sun crust. It is buried 30-60 cm throughout the region and is producing 'sudden planar' results in stability tests.
- If triggered the persistent slab may step down to deeper layers resulting in large avalanches.
Elevations:Treeline, Below Treeline.
Deep Persistent Slabs
The potential for deeper releases on the basal layers still exist. Several large avalanches have occurred on this layer in past few days. See forecast details.
- Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.
- Avoid shallow snowpack areas where triggering is more likely.
Valid until: Jan 15th, 2020 4:00PM