West Slopes South

The recent quiet weather allowed most avalanche issues to gain strength and should result in generally safe conditions Saturday. However, you could still find an isolated pocket of unstable snow in wind-affected alpine terrain or on steep rocky slopes during periods of sunshine.

Saturday should be our last day before the mountains experience a substantial change in the weather. During this transition day, you should find generally stable snow and possibly challenging travel conditions. You may encounter breakable crusts, icy slopes, hard rough surfaces, frozen avalanche debris, open creeks, and lingering pockets of powder. Later in the afternoon, an incoming storm will begin to affect the West South zone. This could result in a few sprinkles and flurries for the Volcanoes, increasing clouds, and higher wind speeds. Make sure you anticipate these deteriorating conditions and build them into your plan for the day. 

While you should find a generally stable snowpack Saturday, that doesn’t mean you couldn’t encounter an isolated avalanche issue. There are two possibilities where you may see unstable snow. 

-Wind Affected Alpine Terrain: If your plans call for traveling into more alpine-like terrain you could run into isolated wind drifts from earlier this week. These firmer slabs were more prevalent on the Volcanoes, but could also be found closer to the Cascade crest. Look for hard smooth pillow-like drifts as you travel. Consider going around them, especially in high consequence terrain. 

-Loose Wet: There’s a good chance the sun will make an appearance on Saturday. That combined with relatively mild temperatures could cause the shallow soft surface snow to become wet and sticky. This should only result in piles of rollerballs, but you could see a few small loose wet avalanches. These natural slides would most likely originate from steep rocky slopes sitting in the sunshine. However, you may trigger them on any steep slope when you find a few inches of wet heavy snow. 

As we head into a more active weather pattern Saturday night, our eyes are on the upper snowpack and what the new snow will bury. Most notably, a layer of weak facets (3/8) has been observed in some locations. These small (1-2mm) weak grains are typically found just above the very prominent Early March Crust (formed by the atmospheric river) on NW-NE aspects at mid and upper elevations. Right now, we haven’t received any reports of these facets on more sunny slopes or at lower elevations. However, the West South is a big zone and we could use your help. Send us an observation of what you find in the upper few inches of snow. If you see sugary facets, you’ve found our potential weak layer.