Quick report
- Cracking
- isolated
There is about 1.5-2' of new snow at Bunny Flat, and skinning from the parking lot is again easy and mostly obstacle-free. Light/moderate snow showers at Bunny Flat shifted to intermittent sunshine around 130pm. Measured 165 cm total snow depth with 55 cm of new snow in a sheltered clearing at Horse Camp. New snow below treeline was fairly dense and moist with ~6" of ski penetration. Snow surface progressively moistened with intermittent sun exposure. Snow near treeline in Giddy Giddy Gulch was moderately wind affected with only a couple inches of ski penetration. Below 7500' in Giddy Giddy Gulch (around 2pm) the snow was quite moist and sticky. Snow shower dropped another ~1" of snow between 2-4pm. Near/above treeline in lower AG snow was also moderately wind affected with a bit of a wind crust producing ~1-2" of ski pen. Snow surfaces up to my high point of 8900' were moistened from the sun, with drier snow below the 1-2" wind/sun crust. I was able to carve turns through this crust on my descent so ski quality was still good, but if the crust was just a bit more stout (like it could be after a refreeze tonight) it would have been poor ski quality breakable crust. More westerly aspects held slightly softer less wind affected snow near/above treeline in lower AG. Wet/rimey clouds were starting to move back up AG on my descent. Temperatures were near- to slightly above freezing most of the day, and felt hot in the sun. No-to-light winds. Isolated cracking on unsupported wind drifted features near treewells near treeline. Failure layer was within the new snow, not on the old/new snow interface.
Snowpack
Performed an ECT at 8200' on a leeward W aspect (41.37285,-122.22154), 30 deg slope, at 4pm. 195 cm total snow depth, 70 cm new snow depth. Below 125 cm old snow not observed, appears to be consolidated and at least P hard. Hardness profile of new snow: 125-135 cm F, 135-145 cm 4F, 145-195 cm F. ECTN2 at 180 cm, no propagation on subsequent taps. Shovel shear on the tested column produced a propagating failure at 145cm.
Avalanche
- Size
- D3 R3
- Type
- SS
- Aspect
- SW
- Trigger
- N
- Elevation
- 11400 ft
Forecasters have evaluated the avalanche off Green Butte Ridge that was initially reported on April 12th. This very large natural storm slab avalanche likely ran during peak storm intensity on April 11th or in the early morning hours of April 12th. A crown line can be seen handrailing upper Green Butte Ridge and wrapping westward into Avalanche Gulch beneath the AK chutes. The avalanche produced a substantial debris pile and lengthy track. The avalanche failed on a layer of buried graupel above a crust.