Soldier & Wood River Valley Mtns

You may be able to trigger small avalanches where the wind has drifted snow and built stiff slabs, and loose snow avalanches are possible on very steep slopes. While small, either of these could be enough to knock you off your skis or sled and send you downslope. Generally stable avalanche conditions exist, and large avalanches are unlikely. 

While large avalanches are unlikely in this zone, there are still a few things to keep in mind as you are traveling in the mountains today. Encountering these small, isolated hazards in the wrong sort of terrain can have high consequences:

WIND SLABS: Over the past few days, skiers and riders have found unstable drifts of snow on middle and upper elevation slopes across our region. On Saturday, a skier triggered a wind slab avalanche (crown photo, debris photo) in the Sawtooths. It broke about a foot deep and 50' wide.  On Sunday, in the Trail Creek drainage near Ketchum, I found similar slabs along upper elevation ridgelines (video here). An observer yesterday reported seeing a small avalanche that had been triggered by an elk in the foothills around the Wood River Valley. Look for these slabs in any terrain that is exposed to the wind. Strong winds over the past 24 hours may have helped to build another round of these thin slabs.

How do you look for them? Surface textures such as ripples on the surface are good signs that the wind has been at work. Be alert to changes in how the snow feels as well. If it quickly gets denser and stiffer you've likely found one of the isolated slabs. Even though they are small, these slabs may be reactive to your weight thanks to the very weak snow they are resting on.

LOOSE SNOW AVALANCHES: Loose snow slides start out at a point and fan out as they travel down the slope. Today's may come in two flavors:

• DRY - If you are finding cold snow to ski and ride through on steep slopes you may be able to trigger a dry sluff. At lower elevations, much of the snowpack has faceted, creating "great" conditions for these "facet-lanches". 
• WET - Today will be a bit cooler than yesterday, but if you are playing in sunny, steep, rocky terrain during the heat of the day you may be able to trigger one of these small slides

Both of these types of loose snow avalanches are relatively easy to manage, as long as you're paying attention. However, they can also both produce slides large enough to knock you off your feet and send you down the slope at speed, thanks to the stiff snow surfaces underneath.

PERSISTENT SLABS: Weak, faceted snow exists near the base of the snowpack on upper elevation shaded slopes in this zone. This layer is more common in the slightly deeper snowpacks found near Dollarhide and west to the Soldiers. Triggering an avalanche on this layer is unlikely, but it's not entirely out of the question on slopes with the following characteristics:

• Very steep: slopes steeper than about 35 degrees.
• Rocky: slopes with variable snow cover due to the roughness of the terrain.
• Wind-affected: slopes where winds produce variable snow depths.

Want to catch up on what happened last week? Be sure to check out the latest weekend update from Chris.