Avalanche Forecast
Issued: Jan 13th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs and Wind Slabs.
AL,
Avalanche Canada
While freezing levels remain elevated and winds values continue to transport snow at upper elevations, the forecast team has little confidence in how the deeper instabilities will react to these changes. Although natural avalanche activity has subsided on the deep persistent problem, we still continue to see reports of human triggering.
Summary
Confidence
Moderate
Avalanche Summary
No new natural avalanches were observed or reported Friday. lake Louise snow safety produced slab avalanches to size 2 with the use of explosives. These avalanches were failing on reloaded bed surfaces.
Snowpack Summary
Moderate to strong SW winds have created windslab at upper elevations. In protected areas, 10-20 cm of loose snow sits over a denser mid-pack which has formed a slab over the weak facet layers below - this loose snow is getting blown into slabs. The December 17 weak layer is down 25-60 cm and becoming less reactive. The November 16 deep persistent layer of facets and depth hoar is near the base of the snowpack, continuing to show sudden failures.
Weather Summary
Warm temperatures will continue Saturday with freezing levels near 1600m. Light flurries are expected on the Western slopes of the region with trace accumulation throughout the day. Ridgetop winds will begin to weaken Friday evening. More unsettled weather is forecasted for Sunday and the start of the week.
Terrain and Travel Advice
- Use careful route-finding and stick to moderate slope angles with low consequences.
Problems
Deep Persistent Slabs
The lower snowpack is comprised of weak facets, with a slab formed over this weakness at treeline and in the alpine. This weak basal layer is uniform across most of the region and has the potential for human triggering and larger avalanches. With warm temperatures over the weekend, we may see some activity on deeper facets below the treeline, especially in the East where temperatures will be the warmest.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
On Friday, wind values ranged from Moderate to Strong at upper elevations with some areas gusting to extreme. With increased winds and up to 20cm of loose snow available for transport, we expect isolated windslab development in the alpine.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Jan 14th, 2023 4:00PM
