Issued: Mar 29th, 2023 4:00PM
The alpine rating is Deep Persistent Slabs and Loose Wet., the treeline rating is , and the below treeline rating is Known problems include
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.
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).
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 30-110 cm down, which remain a concern in steep terrain. The bottom of the snowpack consists of weak basal facets in many areas, with sudden test results still occurring.
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
- Uncertainty is best managed through conservative terrain choices at this time.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Cornices become weak with daytime heating or solar exposure.
Deep Persistent Slabs
The lower snowpack consists of several weak layers that remain a concern. A combination of basal facets, and crusts are still possible to trigger. We are still seeing regular avalanches releasing on the deeper layers and snowpack tests are still giving moderate to hard sudden collapse results.
Aspects: All aspects.
Elevations: All elevations.
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.
Valid until: Mar 30th, 2023 4:00PM