Avalanche Forecast
Regions: Little Yoho.
With temperatures climbing and the potential for sunny periods on Tuesday, expect both Wind Slabs and the deep Persistent Slabs to become more sensitive to natural and human triggering.
Weather Forecast
Warming temperatures are likely to be the dominant input over the next few days. Expect freezing levels to approach Treeline on Tuesday with diminishing cloud cover however West winds should also be increasing and may moderate the temperatures . Watch local conditions carefully and consider heating both at your level and on the slopes above you.
Snowpack Summary
40-60 cm of new snow over the past 11 days followed by extreme SW winds has created new snow slabs over various layers of weaker facets, surface hoar, and buried wind layers. In below treeline areas, this new snow load is sitting on a snowpack entirely made up of facets and depth hoar.
Avalanche Summary
Numerous natural and explosive triggered avalanches were observed and reported throughout the forecast region up to size 3 in the last 72hrs. Avalanche control Saturday found thin, sensitive hard slabs and touchy cornices in the alpine. Soft slabs over the persistent weak layers failed easily at treeline and easily entrained loose snow BTL.
Confidence
Freezing levels are uncertain on Wednesday
Avalanche Problems
Wind Slabs
Strong to extreme winds from the SW have created wind slabs and fragile cornices that are ripe for triggering. Give avalanche terrain a wide berth and remember that fracture lines may extend further that you expect with hard slabs in alpine areas.
- If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.
- Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.
Aspects: North, North East, East, South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 3
Persistent Slabs
The recent snow has created a touchy slab over the weak facets at all elevations. Avalanches that have run full path have been observed in many areas.
- Use conservative route selection, choose moderate angled and supported terrain with low consequence.
- Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 2 - 3
Loose Wet
With temperatures climbing, all it will take is a brief period of clear skies and calm winds to have a major impact on steep slopes. Small solar or temperature triggered events are likely as the snow becomes moist.
- Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.
- If triggered the loose wet sluffs may step down to deeper layers resulting in large avalanches.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood: Likely - Very Likely
Expected Size: 1 - 2