Fresh snow and strong winds blowing from the west-northwest are creating sensitive, soft slabs at mid and upper-elevations. Slopes facing NE-E-S will be the most likely places to trigger fresh drifts, but look for and avoid any cross-loaded terrain features. Yesterday, strong winds blowing from the south created stiff drifts that are now buried and hidden beneath today's fresh snow. These booby-trap slabs are most likely to exist on upper elevation slopes facing NW-N-E and may be triggered further down slope and break above you.

Backcountry observers noted surface hoar and near-surface facets formed above a crust on north-facing aspects. This may lead to sensitive conditions, with avalanches that break wider-than-expected, and the potential to be triggered from a distance.

Any avalanche triggered on mid and upper elevation terrain has the potential to step down to a persistent weak layer, resulting in a very large, deadly, hard-slab avalanche.

Strong ridgetop winds yesterday in the upper White Pine drainage. Photo: Kelly

The DJL (Dry January Layer) of facets is buried 2–4 feet deep beneath a hard slab of settled snow and crusts. Avalanche activity on this layer has gone quiet since February 26th. In my last few days of fieldwork, the layer remained soft and weak but began showing signs of strengthening. Snowpack tests continue to show that the layer is very difficult to initiate; however, once a failure occurs, it still propagates across the column.

This is a low-probability, high-consequence scenario. While it may be difficult to trigger this avalanche, the resulting slide would be very large and likely unsurvivable. Uncertainty regarding this problem is growing as strong winds and snow begin to add stress to this layer.

For now, I recommend avoiding steep, rocky, upper-elevation slopes facing W-N-E where this problem is most likely to be triggered.

Avalanche occurrence on the PWL chart below -