Conditions are tricky now, given recent extreme winds, persistent weak layers, warm temperatures and sun. See the Special Avalanche Warning (SPAW) above for more details.
The Mt. Whymper intermittent closure zone will be closed on Saturday, March 1 for avalanche control. No backcountry activities in this area for the day.
Recent storm snow and extreme winds have added to older slabs. Now up to 60cm thick, these slabs sit over numerous weak layers of facets, surface hoar, or sun crust. Human triggering will remain likely over the short term.
Clear skies and warm temperatures have and will be a driver for some natural activity out of steep terrain, especially in the sun. These smaller slides could trigger the persistent layers, resulting in bigger slides.
Numerous natural avalanches were reported in the adjacent Banff area on the persistent layers. For descriptions, check out the avalanche summary in that bulletin.
On Thursday, helicopter avalanche control on Mt. Field, Stephen, and Dennis produced slab avalanches up to size 3. Any spot that looked like it could avalanche, did. Many avalanches triggered slabs from the side walls of the path.
Winds in alpine and treeline areas have blown 10 - 30cm of snow from last weekend. This snow sits over previous slabs and is now up to 60cm thick. The slabs sit on weak layers of facets, surface hoar or sun crust formed in late Jan and Feb.
The mid and lower snowpack is mostly well-settled, though it is heavily facetted in thin snowpack areas. Tree-line snow depths range from 120 cm to 180 cm.
Saturday - Freezing levels to 2500m, light winds and no snow
Sunday - Much the same
