Cornice failure and wind transport on Incline Lake Peak

Location Name: 
Incline Lake Peak
Region: 
Mount Rose Area
Date and time of observation: 
Thu, 12/30/2010 - 14:30
Location Map: 
United States
39° 17' 32.622" N, 119° 56' 29.0112" 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: 

North-Northeast winds scoured the NW-N-NE-E aspects near ridgelines during the day today. New 6-8 inch wind slabs formed on the SE-S-SW aspects above treeline. Ski cuts and cornice drops did not cause these slabs to fail on slopes less steep than 37 degrees. On slopes steeper than 37 degrees some skier triggered and cornice triggered cracking did occur on test slopes. ON the NW-N-NE aspects hand pits and general observations showed significant settlement in the new snow and good bonding within the new snow. Ski cuts and cornice drops on slopes wind-loaded during the storm did not produce any results. Some skier triggered cracks did occur if I undercut the test slope before ski cutting it.

Photo 1: Mini van sized cornice dropped onto a 34 degree, SE facing, newly wind-loaded slope did not trigger any slabs failure.

Photo 2: Oven sized cornice dropped onto a 39-40, SE facing, newly wind-loaded slope triggered some small shooting cracks the ended as soon as the slope angle dropped below 36 degrees.

Video: Northerly winds transporting snow

 

Snowpit or crown profile photo or graph: 
Snowpit videos (tests, etc): 

20101230INclineLakePeak 005

Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
25% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Moderate
Precipitation: 
None
Air temperature trend: 
Static
Wind Direction: 
North
Accumulation rate: 
More detailed information about the weather: