West Slopes South

Due to continued snowfall, a weak snowpack structure, and strong winds, dangerous avalanche conditions will exist throughout the zone on Saturday. Don't try to thread the needle or outthink Mother Nature; this isn't your typical Cascadian snowpack. You must dial your travel plans way back and contemplate avoiding avalanche terrain altogether.

After a month-long mid-winter break, we finally returned to the snow department in the West South zone on Friday. Although the storm started strong, water numbers ended up roughly half of what was forecast, resulting in a busted weather and avalanche product. Sometimes, that's how it goes, so we'll realign and look forward to Saturday. 

January's snow drought left us with plenty of weak snow on and near the surface. Variable has been the name of the game, with no discernable pattern in the distribution of surfaces. Near-surface facets, surface hoar, melt-freeze crusts, and wind-affected snow were intermingled throughout the landscape, often within feet of each other. The weak grains haven't been a problem to date, but now the time has come. This storm is building the required slab over them, and eventually, some slopes will reach their tipping point. Crusts will make an excellent sliding surface for any potential avalanche, and weak grains could result in more persistent-style slabs. We aren't jumping right into a persistent slab avalanche problem due to the spotty distribution of weak snow, but we may get there. You could see more surprising avalanches on shaded slopes and more failures on a crust on sun-exposed slopes, but don't fully take that to the bank.

NWAC forecasters were along the crest on Friday, gathering information at White Pass and Crystal Mountain. Reports were somewhat contradictory, helping to highlight the variability we've been discussing. One piece of alignment was that the weak snowpack structure still did not have the required slab to pose a problem. Snowpack tests like propagation saw, tilt, and extended column highlighted the weak structure and its tendency to fail but did not result in propagation. As mentioned above, that is changing, and we could get there Saturday or maybe already have in areas like the volcanoes where more snow fell Friday. At lower elevations, heavy wet snow existed due to mixed precipitation and rain. As temperatures lower Friday night, we should be in the snowfall game for the rest of the weekend. Strong to very strong winds will impact the zone, drifting snow into thicker drifts in exposed areas. Take extra care around those classic wind-loaded areas such as convex rollovers, leeward ridgelines, or rocky terrain such as the base of cliffs or sides of gullies/chutes. Natural avalanches could occur during or shortly after periods of strong winds or heavy precipitation.

To sum it all up, we have a unique snowpack setup for our region and are in the midst of a standard Cascadian storm. Multiple long-time avalanche professionals have mentioned that the last time we had a similar snowpack was in 2017-2018, which resulted in 7 deaths throughout the Cascades in roughly a week. You can read the accident reports here to re-familiarize yourself. Needless to say, many professionals are on edge about how the next few weeks will play out. And that starts with Saturday.

So dial your terrain choices way back, and let the storm play out. We know that everyone has pent-up desires after a lackluster January in the snow department. Take a moment to think and get your head back into the avalanche game after your mid-winter break. You may want to consider avoiding avalanche terrain altogether. And please let us know what you see out there, avalanches or not, by submitting an observation. Now is the time for information sharing within the community.