Avalanche Forecast
Regions: Little Yoho.
Time to refresh on the Spring Conditions hazard rating. For Wed - Thurs, expect a daily melt-freeze cycle. Hazard ratings reflect the highest danger for the day.
Powder exists on high north aspects. The persistent problem is a concern for terrain selection on north aspects & south aspects when crusts melt.
Start & finish early!
Confidence
Moderate
Avalanche Summary
No avalanches were observed or reported on Monday or Tuesday.
In the adjacent forecast zone, a skier crossing the slope triggered a size 1 slab that failed on the persistent basal facets just below Peyto Lake viewpoint. Sunshine patrol also a slab avalanche, likely triggered by a loose wet avalanche, that scrubbed to ground resulting in a size 2.5 avalanche on an alpine SSE aspect. Similar activity could be expected in thinner snowpack areas in Yoho.
Snowpack Summary
Light wind effect in the alpine. On alpine north aspects 15-30 cm of dry settled snow sits over the Mar 27 crust that exists to ~2500 m. On solar aspects sun crusts are present to ridgetop with moist snow later in the day. A supportive surface crust exists in most places below treeline.
70-130 cm of firm snow sits over the Jan facet layer which remains a concern in thin areas. In deeper areas the lower snowpack is well consolidated. Treeline snowpack depths range from 150 to 250 cm.
Weather Summary
Wednesday - A mix of sun and cloud with scattered flurries and moderate SW wind. There is some variation in the predicted cloud cover and temperatures between the weather models and across the region. Wednesday night, we may see a reasonable freeze with clearing skies and treeline temperatures dipping below -10°C
Thursday - mostly sunny
See the weather table for more details
Terrain and Travel Advice
- Avoid steep, sun-exposed slopes when the air temperature is warm or when solar radiation is strong.
- Start your day early and be out of avalanche terrain during the heat of the day.
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 crusts are weak or breaking down with daytime heat.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 2 - 3
Wind Slabs
5-10 cm from Tuesday night with WSW wind has formed thin windslabs on alpine lee features reactive to ski cuts by ski hill snow safety teams.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1 - 2
Loose Wet
The degree of cloud cover varies between weather models for Wednesday. This problem will emerge IF surface crusts break down with prolonged solar radiation.
Aspects: South East, South, South West, West.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 2