Wet snow avalanches on Incline Lake Peak

Location Name: 
Incline Lake Peak
Region: 
Mount Rose Area
Date and time of avalanche (best estimate if unknown): 
Sat, 04/24/2010 - 12:30
Location Map: 
United States
39° 17' 34.656" N, 119° 56' 18.3516" W
US


Red Flags: 
Recent avalanche activity
Whumphing noises, shooting cracks, or collapsing
Rapid warming
Obvious avalanche path

Observation made by: Forecaster
Avalanche Observations
Avalanche Type: 
wet,slab,loose,
Slope: 
37degrees
Trigger type: 
Natural
Crown Height: 
1 ft
Aspect: 
Southeast
Weak Layer: 
Old Snow
Avalanche Width: 
30ft.
Terrain: 
Above Treeline
Elevation: 
9 000ft.
Bed Surface: 
Old Snow
Avalanche Length: 
500ft.
Number of similar avalanches: 
3
More detailed information about the avalanche: 

Several point release avalanches occurred on 35-40 degree SE-S facing aspects yesterday and today. Some of these occurred naturally and some were skier triggered. On 35-37 degree test slopes today, ski width wide sluffs occurred in response to ski cuts on SE facing slopes between 8600 and 9200'. The failure layer for these slides was the interface between the older melt-freeze crust and the recent new snow. Skier triggered whumphing and collapsing occurred this same failure layer on near by 30-32 degree, SE facing slopes. The snow on the sun exposed aspects melted and softened quickly today as the sun hit the slopes. Several inches of saturated wet snow existed on the sun exposed SE-S-SW aspects by midday. On the northerly aspects, any areas that received any amount of sunshine had wet, sticky snow on the surface which quickly refroze into a thin crust once the sun left the slopes.

Photo 1: Overview of the SE side of Incline Lake Peak. 2 natural slides are visible in the photo. The point release on climber's left seems to have occurred yesterday, while the point release the triggered a wet slab on climber's right occurred between 11:00 am and 12:30 PM today.

Photo 2: Closer view of today's wet slab that was triggered by the point release. Photo has been filtered to highlight the contrast and make the avalanche more visible.

Photos 3 and 4: Skier triggered wet snow sluffs on 35-37 degree, SE facing slopes that occurred around midday today.

Avalanche Photos: 
Weather Observations
Cloud Cover: 
Clear
Air temperature: 
Above Freezing
Wind Speed: 
Moderate
Precipitation: 
Air temperature trend: 
Warming
Wind Direction: 
Southwest
Accumulation rate: 
More detailed information about the weather: