Northern San Juan

Avalanche

Mark Allen · Feb 28, 2014 · Northern San Juan

Weather

The front moved in slow all day after the break in Feb 27th storm. Snow started again around 3:30pm. Some blue but mostly OVR-OBS. Wind near the ridges 10-15 but must evidnce of previose blow-snow and the 6hr wind event (20-30)G60 night of Feb 27th.

Snowpack

We only took time to look at the new storm and wind slabs at RMP. 12K and below there is a interstorm-weak-interface in storm snow. This interface is due to the high density DF that came in early, however the remainder of the storm ppt was rimed stellars and groppel. This is not bonding well VE-HSx6 all aspects. The DF/Melt freeze crust interface below the HN24 (total of 25-60cm BTL and 0-60cm >TL) reacts to CT but will not propagate when provoked. No ETC. The wind event was NW-SW 6hours; creating isolate alpine wind slabs (small and large) and more unifiform depositon N-TL and BTL Storm slab 11,800-11,500 and below.We noted the 10-25cm rimmed-stellar storm-snow began to crack proximal to the ski but never further. I would predict sluff slides to run further in steeper terrain.

Avalanche

We saw evidence of a large slide mild-slope on the a persistent interface in Millcreek from 550, unrelated to our day or obs location. R3D2.5. If this was not obsurved prior to the 28th then it occurred during the storm and might have release Nautural during the wind event. reported here