Wind Effect Lee Vining Canyon

Submission Info
Volunteer Observer
Friday, February 5, 2021 - 10:00am
Red Flags: 
Recent loading by new snow, wind, or rain
Obvious avalanche path
Snowpit Observations
More detailed information about the snowpack: 

The wind and sun have taken their toll on N and E facing slopes respectively between 7400' and approx. 9600' in the lower portion of Lee Vining Canyon. By 10 a.m. snow surfaces on E aspects were moist. N aspects in sheltered treed terrain held dry, soft surface snow below 9000'. More wind exposed areas near tree line were a patchwork of soft snow, breakable wind skin, and firm, supportable windboard. On the descent, we counted more good turns than bad, but the various surface conditions kept us guessing.

Probing along our route revealed up to 90 cm of snow which was mostly rightside up with the exception of loose faceted snow near the ground. At approx. 9400' I dug a quick pit on a NNE aspect where we found 70cm of snow. A 4F to 1F hard slab sat on top of a melt freeze crust which capped about 20cm of loose faceted snow. Shovel shear test was moderate failing on top of the MFcr and we also got an ECTN result. We noted no cracking, collapsing or other signs of instability throughout our tour. The snow surface was littered with twigs, needles and cones from the recent strong winds. See photo of settlement cone :). Settlement cones noted on trees, brush and boulders also.

We stuck to lower angle terrain, mostly in the trees and avoided the wind ravaged alpine. There was some evidence of previous avalanches during last week's storm, but this has mostly been obscured by blown in snow and settlement. Winds were calm to light out of the NW at this elevation range, but stronger NW winds were evident at the higher elevations along the crest where light to moderate snow transport was evident. This increased by 1:00 p.m. Southerly aspects will not last long in this region at the middle elevations.

Snowpack photos: 
Weather Observations
Blowing Snow: 
Cloud Cover: 
Air temperature: 
Above Freezing
Wind Speed: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: 

Pogonip in the Mono Basin was starting to fully break around 1 p.m.

-- placeholder --

ESAC receives significant financial support from ...