East Slopes South

If you are not standing on a firm crust on Wednesday, then you are in snow capable of producing dangerous avalanches.  Wet slabs linger long after heavy rainfall, producing widely propagating avalanches on slopes as shallow as 30 degrees while wet loose avalanches may be triggered early in the day in wet surface snow on slopes steeper than 35 degrees. With plenty of uncertainty surrounding the wet avalanche problems and refreezing upper snowpack, dial back your activity and reduce your exposure to large avalanche slopes.

Bumping Ridge at 4600 ft added 5 inches to it's snowpack Monday and Monday evening before losing 3 inches to consolidation when the snow changed to heavy rain on late Monday night through Tuesday. At higher elevations, Green Lake at 5900 ft added 8-14" of snow height before losing 6" to consolidation after the changeover to rain. With temperatures now at or exceeding 40 degrees up to 5900 ft, we expect that all elevations received rain and we're dealing with a wet upper (or perhaps entire) snowpack.

Given our uncertainty regarding how the snowpack is handling the water and how quickly it will refreeze you'll be well served to adopt an assessment mind-set on Wednesday as dangerous conditions may linger into the day. Look for signs of very recent avalanche activity to provide clues. Cracks opening on slopes may indicate that glide avalanches may fail on smooth rock faces. Avoid traveling on or beneath smooth rock faces or steep convex rollovers where the slope may have a history of glide avalanches.

In spite of significantly colder (below freezing temperatures on Wednesday) the surface may be slow to refreeze and you might find yourself sinking into deep, wet snow. In this case, Wet Loose avalanches may be large, destructive and deeply entraining.

If you are traveling on southerly slopes, melt-freeze crusts formed prior to this storm cycle could form a bed surface for water percolating through the snowpack to pool and create a large and potentially widely breaking wet slab avalanche. You can dig down approximately 1 ft in the snowpack and check for free water in the snowpack which may help identify whether conditions exist for wet slab instability.

When in doubt, travel on smaller terrain features, ridgelines, or forested areas to maintain a suitable margin of safety given the lower probability, higher consequence wet snow problems.

Shallow wind slabs may form due to up to several inches of fresh dry snow and moderate to strong W winds transporting these onto lee slopes. Steer around wind-loaded slopes and lens-shaped pillows where you might have 6" or more of dry snow over the gradually refreezing upper snowpack.

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.