New snow and sustained ridgetop winds will continue into Tuesday. You can trigger avalanches in wind drifted terrain, especially in the alpine. Observations from this zone are limited - check the forecasts from West North and Stevens Pass for more information.
As more snow arrives you may encounter softer, shallower storm slabs near and below treeline. You are most likely to trigger one of these avalanches on convex rollovers and/or on steep unsupported slopes. Cracking in the new snow and recent avalanches are great indicators of storm slab avalanche potential.
Example of a storm slab in steep terrain below treeline.
Photo: Mt Hood Meadows Patrol
New snow and moderate to strong winds have created a patchwork of instability on the new / old snow interface. Although we have limited observations in this zone, many natural and human triggered avalanches occurred Sunday night and Monday in surrounding areas.
Watch your slope angles, stay off slopes steeper than 30 degrees and well away from large, steep features. Pay attention to signs of instability such as recent avalanches, shooting cracks, and whumphing.
A very large avalanche was observed on Mt Mastiff around December 26th and several very large avalanches occurred in the West North zone (since Christmas) on a deeply buried layer of surface hoar. There is a lot of uncertainty around the presence of deeper instabilities in the West Central zone, but if the layer is there this storm could begin to tip the scales.
Shooting cracks and whumpfing collapses are red flag signs of instability and should drive you to lower angled terrain.
Photo: Robin Pendery
