Red Cone > Crystal Lake > TJ Bowl

Observer: d lewis
Date: Apr 13, 2018, 3:05 PM
Loc: Red Cone > Crystal Lake > TJ Lake
Lat/Lon:37.5859, -119.0148
Elevation: 10000 f
Aspect: NE Angle: 30°
Signs of Instability: Recent Avalanches, Wind Loading
Sky Cover: CLR
Wind Speed: Moderate, Beaufort
Wind Direction: NE
Current Temp:0 to 5°C Trend:➚
Blowing Snow: Light

Comments: Toured up from Twin Lakes trailhead toward Red Cone to assess the new snow and Wind Slab distribution near the Crest. On ascent, air temps were somewhat cool, ranging from +3 to +5, and snow temps at the surface was hovering near 0, 20 cm down -.1 to -.4. New snow from 4/12 was settled out to 5 to 10 cm, where protected. Winds have formed shallow Wind Slabs (~10 -30 cm ) in gullies, depressions, lee side of ridgelines, and under corniced terrain from roughly treeline (~9000’,ish and above). Surface snow was dry on shaded, steep N-NE aspects above~. Slopes with any direct sunshine, the top 2 to 5 cm surface snow was becoming moist, over 2 to 10cm of dry new snow and graupel resting on a very supportive melt freeze crust (pencil+ to knife) 10 – 20 cm thick, overlying 4 Finger to 1Finger, moist poly grains to 30 to 60 cm deep over a dense mid pack that is impenetrable with ski pole probing in most places. Temps remained cool with moderate NE winds and light windloading on NW-SW-SE aspects above treeline (~10,400’ and above). Plenty of crossloading of terrain features but shallow in nature and not overly reactive except in steep terrain and convexities. Hand shears on one of the thicker Wind Slabs (25cm) moderate+, planar, failed on a thin layer of Graupel and rimed stellars (~3-4 cm) resting on top of the near universal Melt Freeze crust from the AR assisted storm on 4/6-7. Moderate winds from treeline and above kept ambient temps cool and help keep the surface snow from becoming overly heated. Shaded, protected, and steep N-NE aspects remained cold’ish and dry from 8500’ and above in the AM, climbing to ~9300’ by the late afternoon, while the remaining aspects the upper 4 to 10 cm softened and became moist but remained supportive. No Loose Wet activity noted. A previously reported (4/7) D2 Cornice failure North of Jaws, on closer inspection looks to be closer to a D3, ran ~1000’ and exposed some rock in the top third of the slide path, debris stopped in the lower third of the path but failed to reach the lake. While what appeared to be a more recent cornice failure slightly further south didn’t run far (~ 400’ vertical) but some of the debris chucks where the size of a good size SUV (think Expedition or Suburban), D3.  Neither slide was capable of propagating a slide beyond the initial boundaries. Creeks are opening up on the north end of TJ Lake, with snow bridges becoming suspect.