Professional Observation

Observation Details

Signs of Unstable Snow

Key Points

We tromped around San Joaquin Ridge from Minaret Vista looking for any fresh, soft wind slabs. Everything we found was hard and stubborn.

• Winds raked this ridge from the west and the northeast. Sastrugi and drifts pointed every which way. The rime in the trees pointed toward west winds being strongest and blowing the longest. We kicked a lot of cornices and test slopes and got limited results. We jumped on a steep test slope in the trees – actually soft snow! – and got no sluffing.
• Almost every surface was wind stiffened. In the trees, skis sank an average of 15 cm into the snow surface and our boots penetrated to a depth of 35 cm. On the exposed ridge ski pen. was 0 to 5 cm. We found sun crusts with small faceting snow crystals between them on solar slopes near a rocky area. We found temperature gradients in the upper snowpack that would drive faceting, though we didn’t find well-developed near-surface facets widespread. The only patches of surface hoar we found had been knocked over by the wind.
• North winds were stripping snow off the top of Mammoth Mountain all day. We saw occasional plumes off Mt. Ritter.