Archived forecast for Sunday, March 3, 2024 This is archived in relation to a fatality on 3/3 on or near Sale Mountain. The avalanche.ca archives are a bit awkward with flexible regions and the result from clicking on the map can differ from that obtained by the location search. We have tried to get the best result by first using the map and then the location search in that area. We believe the advisory here was in effect at Sale Mountain on 3/3. They also date advisories by the ending date so this was listed as 3/4 but expired at 0400 that day. Date Issued: Sunday, March 3, 2024 at 04:00 Valid Until: Monday, March 4, 2024 at 04:00 Prepared by: trettie SPAW In Effect Continue to choose conservative, low consequence terrain and beware of overhead and adjacent slopes. Remote triggering is a concern. Solar input could weaken this already scary snowpack. Danger Ratings Sunday Alpine: 4 - High Treeline: 3 - Considerable Below Treeline: 3 - Considerable Terrain and Travel Advice Conservative terrain selection is critical, choose only well supported, low consequence lines. Remote triggering is a concern, watch out for adjacent and overhead slopes. Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers. Storm slabs in motion may step down to deeper layers resulting in large avalanches. Avoid exposure to steep sun exposed slopes. Problems Avalanche Problem 1: Persistent slab What Elevation? - All Which Slopes? - All Chances of Avalanches? - Likely Expected Size? - Large - Very large A weak layer of faceted grains above a crust buried 60 to 120 cm deep is a recipe for large, high-consequence avalanches. Smaller slabs can easily step down and trigger larger, more destructive avalanches. Avalanche Problem 2: Storm slab What Elevation? - All Which Slopes? - All Chances of Avalanches? - Possible - Likely Expected Size? - Large - Large Storm slabs remain reactive to human traffic. Slabs are particularly touchy where they sit on weak layers of facets or surface hoar. Expect deeper and touchier slabs in lee terrain features near ridges. Avalanche Summary Numerous large to very large natural and human triggered persistent slab avalanches continue to be reported throughout the region. Some have run full path to valley bottoms. Many of the human triggered avalanches have been reported as remotely triggered (from a distance). This speaks to the sensitivity of the persistent slab. As natural avalanche activity tapers, the snowpack will remain primed for rider-triggered avalanches. Snowpack Summary A variety of surfaces can be found including a new crust on sun exposed terrain and wind effect in the alpine. 50 to 120 cm overlies a layer of surface hoar in wind-sheltered terrain, weak facets, or a hard melt-freeze crust on south and west-facing slopes. A thick and hard widespread crust that formed in early February is buried about 70 to 150 cm deep and extends up to 2400 m. This crust may have a layer of facets above it. The snowpack below this crust is generally not concerning except in shallow alpine terrain. Weather Summary Saturday Night Mostly cloudy with 5 to 10 cm of new snow. 15 to 30 km/h southeast alpine wind switching to southwest. Treeline temperature -11°C. Sunday A mix of sun and cloud with 5 cm of new snow. 5 to 25 km/h south alpine wind. Treeline temperature -9°C. Confidence: Moderate, Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.