Southerly winds continue to blow with consistent speeds in the 15-25 mph range. This has drifted the new snow onto many leeward (downwind terrain) aspects and elevations just off the ridge lines. As the winds swirl in the mountain drainages and valleys it's also drifting snow and cross loading sub-ridges and mid slope break overs (see pic). On the shadier aspects the wind will drift snow onto weak sugary crystals of faceted snow and or surface hoar making the issue more complicated. Wind loading is a common denominator in most avalanche accidents.

It will be possible to trigger these new drifts from a distance or from below slopes. Human triggered avalanches are likely. For today, avoid steep (greater than 30°) terrain. Especially in terrain that has pillowy, rounded, or hollow sounding snow at all the mid and upper elevations.

Over the past week we've seen clear skies and cold temperatures. This has created what we call near surface facets (NSF) and surface hoar (SH). Both of these crystals become a weak layer once we bury it. Yesterday, during my field day I dug four different snowpits at different elevations. In each of my snowpits I was finding this faceted snow just under the 4-8" of new snow. Other observers found surface hoar. In the Guardsman's area a snowmobiler triggered an avalanche that failed on surface hoar.

We need to be very cautious on the steep mid and upper elevation shady aspects and assume that this weak snow is there. As the storm adds more and more weight to this layer it could become a serious problem. For now, it's best to avoid any steep shady terrain until we get a better idea of what this weak layer is up to. In shallow snowpack areas where the snowpack is less that about 5' feet deep it's possible to release a much larger avalanche that breaks deeper in the snowpack.

Photo: Snowpit from Mineral Fork showing the weak faceted snow that I found yesterday.

With the rain/snow line around 6,500’ for much of the night, the wet soggy snow will need time to cool. It will be possible to trigger wet, loose sluffs today on all low elevation slopes. Avoid travel in steep gullies and couloirs, including ice climbs. Even a small wet sluff in a steep terrain trap such as a creek bed or road cut can pile up cement like debris burying you deep.