West Slopes South

Increasing clouds and relatively cool temperatures should create generally safe avalanche conditions Saturday. If you’re going to find a hazard, it will likely be a small lingering pocket of wind drifted snow. Use caution around firm pillow-like drifts especially if you’re traveling in high consequence terrain.

The mountains will experience a bit of a transition on Saturday ahead of our next storm system and a generally active weather pattern. Clouds should increase throughout the day and limit the ability for any wet avalanche issues. As a result, the snowpack should be generally safe. If you’re going to find unstable snow it will likely be a lingering slab on a wind-loaded slope. Evidence of recent wind events from this week is everywhere. Textured surfaces, scoured slopes, and sharp drifts abound near and above treeline. Some wind slabs formed in unusual locations due to the easterly winds. While these slabs are a few days, don’t write them off entirely. A fresh wind slab avalanche was found Friday afternoon on the side of the Nisqually Glacier moraine at Mt Rainier (W, 6000ft). This small slide exemplifies the irregular nature of the wind slab problem this week. Be leery of frim pillow-like drifts especially if you plans include higher consequences or unsupported slopes. 

Outside of the wind-affected areas, the surface became much more aspect dependent this week. 

Southerly: Several sunny days formed a breakable crust on many slopes and even resulted in a few small natural loose wet avalanches on Friday. Any wet snow should easily freeze Friday night with clear skies and cool temperatures. Below this surface crust, the recent storm snow has stayed cold and dry. Last weekend’s snow settled significantly this week and bonded well to a very strong spring-like snowpack beneath. Many of the upper snowpack crusts and weaklayers present on other aspects are typically absent on slopes that receive direct sunshine. 

Northerly: On more shaded slopes, a more layered and complex snowpack remains. Between 10-20 “ of light, dry, and unconsolidated storm snow sits over the 2/19 crust. Generally, the bond between these layers improved this week. While the 2/19 crust can sometimes be hard to find, look 1-2” above the more prominent Valentine’s Day layer. Weak faceted grains were observed around and between these two crusts, but snowpack tests have been mostly unimpressive. While we don’t expect any avalanches on these layers Saturday, that could change going forward. 

Very cold temperatures and clear skies this week likely allowed the snow surface to weaken (facet) and surface hoar to grow. As we head into a more active stormy pattern, we want to know where these possible weaklayers exist. Please share your photos and observations of the snow surface with us on Saturday. Thanks for your support.