Wet snow and surface instability on Proletariat

Location Name: 
Tamarack Peak
Region: 
Mount Rose Area
Date and time of observation: 
Thu, 04/19/2012 - 12:05
Location Map: 
United States
39° 18' 57.4992" N, 119° 55' 5.1204" W
See map: Google Maps
US


Red Flags: 
Rapid warming
Obvious avalanche path
Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

Evidence of a decent snow surface refreeze from radiational cooling in this area last night. The top 20 to 30cm of the snowpack had refrozen overnight and remained supportable below 15 cm of wet snow at 11:30am. The snow surface became unsupportable on all aspects between 11:30am and 12:30pm. Northerly aspects did not last much longer than easterly and southerly aspects. Below the surface melt layer, colder moist rounded but not wet or melt freeze snow existed within the top 70cm of the snowpack studied.

Photos: An easily skier triggered wet small wet loose snow avalanche on a 37 degree section of the slope just below the snowpit location at 12:30pm. Only the top 15 cm of wet snow was entrained.

Video: Looking at wet snow vs. moist snow below surface melt layer.

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

20120419 Tamarack Peak 001.MOV

Weather Observations
Blowing Snow: 
No
Cloud Cover: 
25% of the sky covered by clouds
Air temperature: 
Above Freezing
Wind Speed: 
Calm
Precipitation: 
Air temperature trend: 
Warming
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: 

Building cumulus clouds with no vertical development.