Avalanche Forecast
Regions: Little Yoho.
Solar radiation will peak Sunday.
Start early, and finish early while the hazard is lower.
Confidence
Moderate
Avalanche Summary
Visitor safety staff observed evidence of a cornice failure which triggered a size 2 persistent slab in the alpine on the north side of The President which likely occurred Friday.
No other new activity was observed or reported in this subregion on Saturday.
Snowpack Summary
Surface crusts on all aspects to ~2800 m except north, where up to 30 cm of dry snow is found at higher elevations. On southerly aspects, this 30cm contains several crusts.
Below this, a prominent rain crust (Mar 27) is found everywhere up to at least 2300m and ridge top on solar slopes.
This sits on approx 80 cm of firm snow that overlies the Jan 30 facets. These are stronger in Little Yoho than further east but still show potential for propagation with sudden planar test results.
Weather Summary
Daytime solar radiation is the most important input to the snowpack right now.
Tonight: Clear. Alpine temps: Low -6 °C. Mostly light ridge wind occasionally gusting to 30 km/h. Freezing level at valley bottom. Weak temperature inversion.
Sunday: Sunny. Alpine temperature: High 6 °C. Mostly light ridge wind occasionally gusting to 25 km/h. Freezing level up to 3000 metres on soar aspects
Terrain and Travel Advice
- Start your day early and be out of avalanche terrain during the heat of the day.
- Be mindful that deep instabilities are still present and have produced recent large avalanches.
- Avalanche danger will increase as the surface crust breaks down.
- Avoid steep, sun-exposed slopes when the air temperature is warm or when solar radiation is strong.
Avalanche Problems
Persistent Slabs
Below the recent snow, a 90-150 cm slab sits on the weak Jan 30 facet layer. On all but high north aspects, recent sun crusts and the March 27 rain crust cap this slab, providing some security. Continue to use caution in thinner, high areas or when these superficial crusts are weak or are breaking down.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3
Loose Wet
Crusts almost everywhere on solar aspects, solar inputs will still affect rocky areas. As heating develops, higher and shaded slopes will become affected. Sluffing off of steep rocky faces should be expected and cornice failures are more likely. Isolated wind slab may found in wind prone areas.
Aspects: North East, East, South East, South, South West, West, North West.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 2