Soldier & Wood River Valley Mtns

Avalanche conditions are generally safe. Watch for very isolated pockets of wind-drifted snow at upper elevations. Colder temperatures and cloud cover today should end the wet snow problems caused by this week's rain and very warm weather. 

There is no clearly defined avalanche problem in this zone, and avalanche conditions are generally safe. Watch for very isolated pockets of wind-drifted snow at upper elevations. Colder temperatures and cloud cover today should put an end to the widespread wet snow problems caused by this week's rain and very warm weather. Continue to use normal backcountry precautions—carry avalanche rescue gear, make a plan for the day, and watch for unexpected signs of instability.

ADDITIONAL DISCUSSION:We all know that to have avalanches, you need both a slab and a weak layer. Weak layers usually form in the dry spells between storms; snowfall and wind during stormy periods build the slab. Our 2-month mid-winter drought has produced persistent weak layers near the surface of the snowpack—at least on slopes protected from the intense sunshine, warm temperatures, and wind that have been more common than snowfall. The intense weathering of the snowpack surface means that these weak layers are not as widespread as they could be—they're most common on shaded and wind-sheltered slopes. And—thanks to the dry weather—most of our area lacks a slab atop these weak layers. Here's how it breaks down across the forecast area:

Soldiers & Wood River Valley: The number of inches of snow that have fallen in this zone over the past 2 months can be counted on one hand, maybe two. Where snow still exists, it's often full-depth facets. TL;DR: plenty of weak snow, but little to no slab.

Galena Summit & Eastern Mtns: Weak facets can be found about 4-8" below the surface on shady/sheltered slopes. Slopes with a sufficient slab for unstable conditions have been limited to wind-loaded areas. After nearly every round of wind, folks have triggered small pockets of wind slab sitting on weaker snow.

Sawtooths & Western Smokys: While this zone has received a bit more snow than the Galena Summit & E Mtns zone, the avalanche conditions have been fairly similar. Wind-loaded slopes have been the primary place to find the necessary combination of a slab and weak layer.

Banner Summit: This zone has fared the best during the mid-winter drought. We've been slowly building a slab atop weak layers of facets and surface hoar. The wet storm earlier this week produced 6-10" of new snow at upper elevations. The scales finally tipped, and we observed a cycle of natural persistent slab avalanches breaking 12-16" thick. 

Catch up on what happened with this week's wet, wild, and windy storm in our latest Weekend Update!