Galena Summit & Eastern 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. Either of these could be enough to knock you off your skis or sled and send you downslope. There's a lingering chance of triggering a large slide in very steep, rocky, wind-affected terrain.

While large avalanches are unlikely in this zone, there are still a few things that are worth keeping in mind as you are traveling in the mountains today. In addition to the hazards near the surface, the weak snow buried near the base of the snowpack is at its worst in this zone.

WIND SLABS: Over the past few days, skiers and riders have found small, unstable drifts of snow 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). Local professionals found similar slabs near Galena Summit (photo here) the same day. Look for these slabs in terrain that is exposed to the wind. 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 a few days old now, these slabs may remain sensitive thanks to the very weak snow they were deposited 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. 
• 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 mid and upper elevation shady slopes. The presence of this snow continues to influence the way that I am traveling in the mountains here. 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.