Avalanche Forecast
Regions: Little Yoho.
A warm storm approaches from the west bringing new snow, rain, strong wind and rising freezing levels. The storm arrives Monday, and by Tuesday freezing levels will reach 2500 m and cause an avalanche cycle in the region.
Confidence
Low
Avalanche Summary
Very minimal observations over the past few days except around Mt Field but reports from guides working in the area indicate several large avalanches releasing in steep, wind loaded terrain (up to size 3).
Snowpack Summary
More new snow and even rain will add load to the snowpack and create new storm slabs for Monday and Tuesday. At treeline, 70-100 cm of snow overlies the Jan. 30 / Feb. 22 drought layers, which consist of 20-30 cm of weak faceted crystals. These layers have been reactive in tests and recent avalanches in adjacent areas. In this thicker, western, snowpack region, the facet/depth hoar basal layer is less prominent than it is east of the divide but likely exists in thin areas.
Weather Summary
Snow, warmth and rain are coming our way for most of this week. Expect treeline temperatures to reach 2000 m on Monday, 2400 m on Tuesday and even higher on Wednesday. Along with this comes a mix of snow and rain, with some weather models calling for about 15-30 cm of snow overnight into Monday and Tuesday with rain on Tuesday.
Terrain and Travel Advice
- Make conservative terrain choices and avoid overhead hazard.
- Be careful as you transition into wind-affected terrain.
Avalanche Problems
Persistent Slabs
A 60-100 cm slab overlies mid-pack facets and our limited snowpack tests (Mt. Field only) indicate a generally strong snowpack close to 200 cm deep at treeline. We no observations from the alpine and high uncertainty because our observations are limited in this area.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3.5
Storm Slabs
Small storm slabs may form on Monday with the incoming snow and these will become more reactive as the storm turns to rain overnight and into Tuesday. It its raining, avoid all avalanche terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2