Variable Surfaces on The Sisters

Location Name: 
The Sisters
Region: 
Carson Pass Area
Observation Date & Time: 
Wednesday, February 8, 2023 - 12:30
Location: 
38.663443, -120.012535
Is this an Avalanche Observation?: 
No



Terrain Alerts: 
Slopes Steeper than 30 degrees
Obvious Slide Path
Terrain Matches the Advisory

Observation made by: Public

Tabs

Observation
Description of Snow, Weather, and Avalanche Conditions: 

Skied both a solar (W Couloir) and shady (N Face) line on the Sisters today. Temps were warm and sunshine was abundant, although there was a stiff N/NW wind blowing at the ridges. The West Couloir was smooth, firm and supportable at 12:30, and does not appear to have undergone a full melt-freeze cycle yet. It skied more like windboard, although on the apron, the snow was starting to soften under the sun. On the bootpack and skintrack up the S face of the Sisters, a wide variety of surfaces was encountered, including small panels of wind deposit, a supportable melt-freeze crust, and a more stout water ice surface in numerous locations. In most locations, boot penetration was less than 5 cm, requiring both ski and then boot crampons. A fair amount of wind scouring was evident, with large sections of bare rock. The N Face was wind blasted as well, although on the steep pitch right off the summit, surface faceting was abundant, and made the skiing very enjoyable. Where the slope angle mellowed, there was pretty large wind texture and sastrugi. Neither the N Face or W couloir had any large, continuous sections of wind loading.

On the approach and exit, near and below treeline, the snow was mostly soft in sheltered locations, with no signs of slab development. I jumped on many steep, shady rollovers on the way in and out, and observed no signs of instability- no collapsing or cracking. I pole probed in numerous locations, and found no obvious hardness changes in the top meter. In the morning, a thin melt freeze crust existed in sun exposed areas, and by the afternoon, the snow in these locations was fully wet, with numerous tree drippings as well, making the exit slow, filled with lots of glopping. 

I didn't observe any signs of old avalanches on any of the slopes around the area.

BESbswy