Yost Lake, Four Seasons Trees

AVALANCHE OBSERVATION
Yost Lake, Four Seasons Trees
Submission Info
d lewis
Forecaster
Friday, March 16, 2018 - 2:45pm
Red Flags: 
Recent avalanche activity
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Avalanche Type: 
Dry
Slab
Slope: 
37degrees
Trigger type: 
Skier
Crown Height: 
1 ft
Aspect: 
North
Weak Layer: 
Storm Snow
Avalanche Width: 
10ft.
Terrain: 
Below Treeline
Elevation: 
8 500ft.
Bed Surface: 
Storm Snow
Avalanche Length: 
100ft.
Number of full burials: 
0
More detailed information about the avalanche: 

_Observer: d lewis
Date: Mar 16, 2018, 9:46 PM
Loc: Yost Lake, Four Seasons Trees
Lat/Lon:37.7521, -119.1071
Elevation: 8127 f
Aspect: N Angle: 37°
Signs of Instability: Shooting Cracks, Wind Loading
Sky Cover: OVC
Precipitation: Snow, Moderate snowfall - 2 cm/hour
Wind Speed: Light, subjective
Wind Direction: SW
Current Temp:-5 to -10°C Trend:➘
Blowing Snow: Light
New Snow 24-Hours:50cm Storm:60cm 
Boot Penetration: 40cm
Snow Stability: Fair
Stability on similar slopes: Fair
Avalanche Danger: Considerable 

Comments: 2 Stability Tests: CT4 Q2 21cm CT1 Q2 21cm 4 Snow Pit Layers, Measured bottom up Top Location: 135. Test produced mixed results. Upper 20 cm shows hints of a slab over loose Fist-. Ski cuts on 35 + degree test slopes resulted in small 10' slab releases that continued down slope eroding into the new snow. D1

Blowing Snow: 
Yes
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Light
Precipitation: 
Snow
Air temperature trend: 
Cooling
Wind Direction: 
Southwest
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 
Number of People Caught: 
0
Yost Lake, Four Seasons Trees 37° 45' 7.56" N, 119° 6' 25.56" W
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