Skied north into Lost Lake and east off Mt. Mastiff. Didn't approach anything with a cliff band, shallow trigger points, or overhead hazard. We traveled largely on low-angle slopes aside from a 38-40-degree northerly shot at 5950'.
March 4, 2018, 10:30 a.m. PST
Weather: Skies broken to cloudy, snowing on and off all day; temp hovering below -4C above 5000'. Light east wind in AM becoming moderate west mid-day. Snow building by early evening.
Snowpack: Observation at 5900' North facing. HS > 325 cm. SS 18cm. Boot pen 60-70 cm. The recent persistent weak layers are getting deeper and the slab on the 2/13 facets is gaining strength. Aside from 10-20cm of F/4f snow, 1F snow ran to the 2/13 facets with subtle density change on the shallower 2/23 facets and wind slabs. 33-degree slope. ECTX; CT21 @30cm deep density change (wind). Planar shear on this layer when weighted heavily by skier above pit. Quick observation east facing 6250' 25-degree slope: wind and sun affected snow above 1F to shallow burial of 2/13 facets 50cm down. Not reactive when skiing low-angle slopes. Bottomline: above tree line you can still trigger several different weak layers in steep terrain, including two deep, persistent layers with a firm overlying slab. Manage trigger points and terrain like rollovers, cliff bands, etc. that connect to lower-angle slopes where these layers are present. Stevens Pass and the east slope of the Cascades are in the middle of a low-probability, high consequence situation (aka spooky moderate) that is slowly healing, but is not fully resolved. Sleeping dragons may sleep an awful lot, but they breathe fire when you poke them hard. Don't mess with the biggest lines and open bowls just yet.
Area Description: Lost Lake/Mt Mastiff areas
Avalanches: Evidence of recent solar wet slides on sun-exposed E/SE. Steep, north-facing appeared to have slid naturally during/after the 2/25 storm in 40-50 degree terrain. One natural crown was visible in a rock band above a 50-degree slope. Started as dry loose on overhead rocks.
Observation by Nate Hough-Snee
Did you see any avalanches? Yes
Did you trigger any avalanches? No
Was anyone caught in an Avalanche? No