Red Cone Bowl - East Ridge

SNOWPACK OBSERVATION
Red Cone Bowl - East Ridge
Submission Info
Forecaster
Wednesday, December 20, 2017 - 3:15pm
Red Flags: 
Recent loading by new snow, wind, or rain
Red Cone Bowl - East Ridge 37° 35' 51.576" N, 119° 1' 16.2696" W
Snowpit Observations
More detailed information about the snowpack: 

Toured up toward Red Cone up to ~ 10,000' via the standard route that closely follows the summer trail to assess the new snow, wind transport, initial bonding, and potential Wind Slabs. Slider storm system moved through Mammoth throughout the AM with light snow over the Crest and flurries in Mammoth until ~10:00 AM when snowfall increased to S to S+1. Winds initially, moderate to strong SW flow during pre-frontal passage but quickly swung to the North – Northeast near and above treeline with frontal passage. The system quickly cleared out by mid-afternoon, becoming partly to mostly cloudy, with light snow showers, and light to moderate Northerly ridegetop winds. Snowfall had little evidence of wind effect until nearing treesline along the eastern ridge of Red Cone Bowl with evidence of light to moderate drifting along the Crest producing soft to moderately hard Wind Slabs on E-S-W aspects. New snow in the trees to near treeline 5 to 10cm low density snow (Fist -) over 10 to 15 cm loose facets (Fist) resting on a decomposing wind crust layer (1Finger-). Snowpack tests on a sheltered NE aspect at ~9900' produced no conclusive results. Upon weighting much of the new snow and facets would loosely fall off the column. However, I had mixed results with the decomposing wind crust from 12/3, down ~ 25cm which is breaking down and resting on loose facets (4 Finger+): CTH (23,25, 21) down 25cm in Fist+ hard facets under a 1F- hard crust. Mid-pack: Multiple older P- melt-freeze crusts with thin layers of facets from November. Basal snowpack no significant faceting, 1F- trending to 1F. The primary layer of concern, the facets buried 25cm down with additional slab loading. Snow depth varies greatly near ~9000’ and is pactchy with an icier base, above ~ 9300’ coverage improves on sheltered northerly aspects increases to ~ 65 to 110cm but with plenty of objective hazards the ower you go. Caution on steep sheltered slopes where the new snow and loose facets can produce possible Loose releases. Plenty of open water on the lower lakes, complete with waterfowl. This new coating has covered many of the previously visible obstacles; early season conditions exist for all elevations.

 

Snow profile: Dec 20, 2017, 3:17 PM

Red Cone East

Lat/Lon:37.5977, -119.0212

Elevation: 9900

Aspect: NNE,  Angle: 35

Signs of Instability: Wind Loading

Sky Cover: BKN

Precipitation: Snow, Light snowfall - 1 cm/hour

Wind Speed: Light subjective Wind Direction: N

Blowing Snow: Light,  N

Snow Depth: 110cm, New Snow Storm:10cm

Boot Penetration: 25cm

Comments: 5-10cm new. Light to moderate windloading along the crest. No clear problem layers but anticipate wind slabs along ridge lines on East to South to West aspects with previous loading on NW to NE aspects with frontal approach, although thinner due to less snow available for transport . Upper 1/3 of the snowpack extensive faceting. Mid-pack decomposing  multiple melt/freeze crusts and facets, non-reactive. Bottom ~10cm rounding facets. 

Snowpit or crown profile photo or graph: 
Weather Observations
Blowing Snow: 
Yes
Cloud Cover: 
50% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Light
Precipitation: 
Snow
Air temperature trend: 
Cooling
Wind Direction: 
North
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Quick moving slider moved through the region with snowfall begining in the early AM (~700). Flurries mainly in town, light snow over the Crest. Snow fall picked up around 1000AM with light snowfall in town and moderate over the Crest. This lasted until mid-afternoon when snowfall decreased to scattered showers and winds decreased dramaticly. 

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