East Slopes South

Wind-affected snow may be widespread near and above treeline. Wind slabs may be reactive on specific terrain features such as steep rollovers that extend well below typical start zones. Navigate away from slopes warming rapidly under strong sunshine.

An observation from east of White Pass on Saturday reported that wind loading led to large natural slab avalanches.

The slabs formed during the recent snow and wind event, which brought around 10" snow along with sustained winds up to 71 mph and gusts to 110 mph early Saturday in the White Pass area. Weather stations in the East South zone suggests snow amounts were less than 5".  Wind slabs will remain reactive in the East South zone, particularly on colder, shaded aspects that have been loaded by W winds during the last storm. An avalanche caught and fully buried a rider in the Snoqualmie Zone on Saturday. The avalanche failed on a weak snow interface (near-surface facets) at the 4/9 interface. If similar weak snow grains remain on shaded N and NE aspects in the East South zone, wind slabs may propagate more widely and may remain reactive longer than you expect. Use small test slopes and quick hand pits to evaluate this interface before exposing yourself to large terrain features. Give wind-loaded slopes below fresh cornices or opposite wind-scoured ridgelines a wide berth. Use clues such as textured snow and firm/punchy snow layers to identify and navigate around wind slabs 6" or deeper. These slabs may extend down to mid-slope terrain features and you are most likely to trigger them on a steep, convex rollover.

Areas with 6" or more of dry snow, anticipate a transition to sticky, wet snow and wet avalanche activity as the sun moves around the dial. If you find the surface snow transitioning or observe rollerballs starting to roll downslope, adjust to cooler, shaded aspects and reduce your exposure to steep slopes overhead.

 The sun has exposed rocks near ridgelines and bare ground on some south and west-facing slopes. At low elevations, creeks may contain significant flow and snow bridges are beginning to become suspect.

Dry weather combined with gradually warming temperatures should recommence the transition from a colder layered snowpack to a wet spring snowpack. Meltwater played a role in glide and wet slab avalanches in the Washington Cascades last week. It will become an increasing player as the coming week progresses. If you dig down in the snow, pay attention to how deeply meltwater has percolated, and please consider sharing your finding on the public observations page. This will improve our ability to forecast wet avalanche problems.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.