Avalanche Forecast
Regions: Little Yoho.
Strong solar input will continue Thursday, although if clouds come over it may stay cooler. Avoid exposure to sun-exposed slopes, especially late in the day. Now is the time to make the habit of starting the day early, and finishing early.
Confidence
Moderate
Avalanche Summary
Ski hills and road patrols today were reporting some loose wet avalanches on solar aspects to size 1. Yesterday, one of the local ski hill snow safety teams triggered a size 2.5 with explosives in terrain that had seen extensive previous skiier compaction. This illustrates the unpredictability of the current snowpack and how even with previous traffic, the deep layers can still be triggered with relatively small loads (single hand charge).
Snowpack Summary
Surface crusts exist to ridgetop on solar aspects. On polar aspect, 10-25cm of storm snow sits over a facetted interface from March 25th and buried temperature crusts below 1500 m. The midpack in this area has several crust and facet layers that have been unreactive recently. The base of the snowpack still consists of weaker facets. These facets are mostly a concern in thinner snowpack areas (<2 m).
Weather Summary
Thursday looks to be another mainly sunny day. Air temperatures will start cool but the solar radiation will make solar aspects feel warm unless clouds come over.
Friday and Saturday will see a change in the weather as a low moves in from the coast. Expect increasing cloud on Friday and light snow by the afternoon as alpine winds pick up to strong from the SW.
Expect a few cm's overnight Friday and 5-10 cm on Saturday.
Terrain and Travel Advice
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Avoid exposure to steep, sun exposed slopes, especially when the solar radiation is strong.
- Cornices become weak with daytime heating or solar exposure.
Avalanche Problems
Deep Persistent Slabs
Continue to pay attention to the weaker basal facet layer in areas where the snowpack is shallower (<2 m) such as moraines or wind scoured areas, or in places where a large trigger like a cornice fall could impact the slope. In deeper snowpack areas of this region the basal facets are less of a concern.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3
Loose Wet
Strong solar inputs could produce avalanches in steep rocky solar terrain. Pinwheeling and melting snow near rock are good indicators that the snowpack is being affected by solar radiation.
Aspects: South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1.5