Northern San Juan

Avalanche

Jason Bushey · Feb 14, 2021 · Northern San Juan

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Weather

Saturday 2/13 am had around 3" of new snow at the lot in 24hrs and around 6" of new snow at 11.6K. Damp, warm and generally snowing with a few inches of accumulation over the day. Sunday morning had around 4" of new snow at the lot to start the day in 16hr, and similar amounts at 11.6k, giving a 48hr total around 10-12". Some tracks from 5 days ago were still somewhat visible. The storm seemed to underproduce from what we had expected throughout the day. Warm temps in mid 20s and strong sun throughout the day with solar aspects BTL creating sticky snow. Northerly aspects stayed cold and dry. Wind was light with most trees holding snow throughout the day, and NW aspects near treeline that were rock on Saturday had a fresh coat of snow on Sunday showing not much wind transport on E aspects (see picture) There was a brief period of snow and high winds around 1:30-2:30 Sunday but did not amount to much precip and seemed to go away quick. No new snow was on the car at 4pm.

Snowpack

On Friday 2/13 did and ECT on ESE BTL aspect that two weeks ago had produced an ECTP6 now had an ECTX80cm from the surface. HS was 140. On north facing aspects found HS of 195, and CT tests produced easy but broken results on the new 20-25cm of settled snow, and no results on lower layers. The new snow seemed to come in right side up and bond well to the old surface. There was some variability in snow depths on North btl, with adjacent ridge <1mile away showing 140cm snowpack (55cm less). This snowpack was more suspect as the upper slab was slightly shallower and boot pen easier to hit the ground but no format tests were done. Ski cuts produced no results on slopes up to 40 degrees in timber and no storm slab reaction was found btl. No cracking or collapsing btl all weekend.

Avalanche

Noticed a D2 avalanche on SE facing lookers right of Sound of Music. Potentially an avalanche again on Destroyer, although hard to know when. If so, this would be a repeater. Put picture on for your evaluation. Saw a small D1 roller balls in the alpine originating in S aspects.