Route: Traveled from 900ft to 3800ft on Sunburst Ridge in order to take a closer look at a natural avalanche that occurred on Saturday 2/22 on the SW face of Sunburst. Written up here:
Clear skies and sun
Warm temperatures in the low to mid 20s (F)
Moderate winds with gusts and some blowing snow at ridges
Signs of Instability:
Recent Avalanches – None Observed
Collapsing – None Observed
Cracking – 1 to 3’ cracks surrounding skis in wind loaded areas
Surface Conditions: (see photo)
With the exception of sheltered areas at low elevations, all surfaces were VERY wind affected from Sunday’s “wind event”. Surface conditions ranged from scoured to very hard wind crust, creating challenging skiing conditions in most areas.
We dug a few pits near the crown of a natural avalanche from 2/22 at 3750ft on a WSW aspect. These avalanches released on small facets above the late January rain crust. The crust was thin (2-3mm) and translucent for the top 100′ of the slide and became much thicker (20-30cm) by 3,500′.
The overall snowpack structure is poor. At 3,700′ there was around 30-40cm of K hard wind slab capping the 20-40cm’s of February snow. The February snow sits on a thin facet layer (weak layer in the avalanche) and on top of one or two thin melt-freeze crusts from late January. The snowpack underneath this consists of approximately 1m of harder faceted snow of from 4F – P hardness. In the deeper pack (30-40cm above the ground) we observed large (4mm) facets mixed with cupped grains – approaching depth hoar. (see photo) The ‘thick’ January crust commonly seen does not exist at this high of an elevation.
ECTP22 SC and ECTP20 SC 40cm down on facets above thin January rain crust.