Crusts, Surface Hoar, Winds on Grouse Rocks

Location Name: 
Grouse Rocks
Region: 
Blackwood Canyon or Ward Canyon Area
Date and time of observation: 
Tue, 12/15/2015 - 12:30
Location Map: 
United States
39° 8' 9.024" N, 120° 14' 25.44" W
See map: Google Maps
US


Red Flags: 
Recent loading by new snow, wind, or rain
Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

Hand pits, observations, and tests showed a collapsed surface hoar layer below the recent snow. Tests and observations also indicated that the snow around the crust at the base of the recent snow has started to weaken. The unstable snowpit test results represented the only signs of instability concerning these layers. Ski cuts on test slopes where these layers existed did not cause cracking or collapsing. 25 to 35 cm of recent snow existed above this crust in most places in this area today despite the strong NE winds. 

In the near and above treeline areas, NE winds had scoured some of the snow away from the previously wind loaded slopes and some snow transport was still occurring. Wind slabs that formed on the W aspects remained small and did not extend very far away from the ridgelines. Some skier triggered cracking did occur on N-NE aspects where some of the wind slabs that formed during the storm remained. This cracking only occurred on test slopes that had been previously undercut.

Photo: An example of the largest cracking that occurred on one of those undercut NE facing test slopes.

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
50% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Moderate
Precipitation: 
None
Air temperature trend: 
Static
Wind Direction: 
Northeast
Accumulation rate: 
More detailed information about the weather: 

NE winds transporting snow in above treeline areas.