NE Winds on the Sherwins

SNOWPACK OBSERVATION
Submission Info
Forecaster
Friday, January 27, 2017 - 10:00am
Red Flags: 
37° 36' 28.7208" N, 118° 59' 25.5516" W
Snowpit Observations
More detailed information about the snowpack: 

Quick trip up the Sherwins from the end of Old Mammoth Rd., up the shoulder behind Mammoth Rock, walked along the Sherwin Ridge, dropped down over shoulder behind Mammoth Rock onto the benches below Mammoth Bowl, back down to car.

-Light NNE winds on the skin up. Snow surface showed signs of recent scouring from up slope N winds. 2mm thick wind skin at snow surface. Lots of wind affected snow in open areas. Past SW winds created small cornices and thick pillows on N aspects.

-Settlement cones around almost all the trees in The Hose area and decreased ski penetration from a few days ago show that snow is settling and getting thicker in the upper pack. Top 25cm are still F hardness over a 4F+ layer. Hand shears pulled off on top of the 4F+ layer with hard force, sometimes planar, sometimes rough.

-Debris from several past (>24 hrs old) avalanches still visible on looker's right of Mammoth Bowl and under the ridge above The Hose. All aspects: NE. All slides R1D1 and shallow. The three I saw appeared to have been skier triggered (intentional?) with either cornice drops or ski tracks above or near the debris.

-At the top of the ridge lots of show transport from moderate N winds. Snow banners pointing S from the Sherwin Ridge and the Mammoth Crest seen in the vicinity of Duck Pass. Cornice kick tests on N aspect above The Hose broke around my skis with some hard stomping. Resulting blocks created small shallow sluffing and didn't run more than 20 feet. It seems that there are still some small instabilities at the Sherwin Ridge line and on other features loaded by previous SW winds, but that they are becoming less reactive. Current northerly winds are stripping slopes near ridge line and blowing the snow onto S facing aspects.

-Best skiing was on wind sheltered slopes. Areas exposed to either past SW or current NE winds were a variety of wind board, breakable wind crust, or just thick powder.
 

Snowpack photos: 
Small avalanche debris from last storm
Small debris several days old
Cornice test on Sherwin Ridge
NE winds scouring top of the Perch
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
25% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Precipitation: 
Air temperature trend: 
Warming
Wind Direction: 
Northeast
Accumulation rate: 
More detailed information about the weather: 

ESAC receives support from ...