Observation Date: 02/18/2017
Route/Location:
Jocko Lake Rd was driveable with 2WD in the AM, St. Mary’s Road clear to dirt on the way out. Left from Twin Lakes TH.
Weather:
Mostly cloudy with some brief sunny moments and light wind mainly on the approach ridge. Pretty warm.
Wind:
New Snow: 0-3″
Avalanche Activity:
Forecast was pretty spot on. Below 7,000 ft snow was completely unsupportable, with skis on going down to at least shin deep which made for a tough exit. Above 7,000 feet 0-3+” new snow was sitting on a supportable melt/freeze crust, was super saturated and fairly reactive to hard turns on rollovers etc. Lots of loose wet observed on steep slopes E/W/S. One “whump” observed on flat terrain with shallow snowpack near a dead tree @ ~7,200 ft. Dug a pit in the apron at about 7500 ft on a slope that was <27 according to Caltopo, ~300 cm total snow. 3 very obvious and hard crust layers (other than melt/freeze layer near surface) at approximately 20cm, 45cm and 80cm. All failed on CT between 12-25 hits. Mellow slope so not a lot of energy, but all were clean, planar Q1 sheers. Very dense, iceblock-like slab on the deepest layer. None propagated on ECT but we later realize column was poorly isolated because the bottom most crust layers was so solid our chord wasn’t going all the way through. We’d seen enough and it was an easy call to make not to ski. NOAA forecast calls for 2-3.5′ between Sat night- Mon night. If this materializes it will be sitting on the melt/freeze crust, which has a few cms of graupel on it and 3″ of saturated new snow on top of the graupel.
Other Comments:
Observer: Joe Larson