Blowing Snow near Twin Peaks

Driving into the canyon we saw trees blowing in the wind and clouds moving across the sky. Once we got out of the truck and started up the track, we could see pine needles and other debris strewn across the snow surface and the winds continued to knock snow and dead limbs out of the trees. We decided we should keep moving and not linger under any tree covered areas. On the way up we dug several hand pits looking for any signs of buried weak layers and did not find evidence of instability in non-wind-affected areas. We did notice soft unconsolidated snow made up the top 4 to 5 inches of the snowpack. It felt granular and slippery under our skis (see pit - some near surface facets). Once we gained the ridgeline, the winds increased and were moving snow onto the leeward slopes. Looking north along the ridge it appeared that the wind-loading was only happening in areas where trees came up to the ridge on the windward side. We speculated that the trees sheltered the snow and allowed it to stay soft enough for the winds to transport it. On the ridgeline, we did find some small pockets of wind drifted pillows that would crack when we kicked them, but the wind slabs were small, shallow and did not extend very far downslope. Regardless we chose to retreat into less windy terrain for the descent where the snow remained soft.

Photo 1: Lenticular clouds and some wind transport along the Sierra Crest near Twin Peaks.

Photo 2: Extended Column Test with no fractures from a near treeline line test slope (ECTN).

Photo 3: Small wind pillow with some cracking. The wind slab only extended a few feet downslope.