Observation: Turnagain

Location: Tincan Trees

Route & General Observations

Field Obs 1/13/2013
Tincan Trees

No Recent Avalanches (very poor visibility)
No Collapsing
No Shooting Cracks

Test Pit @ 2400′
HS= 200cm
ECTP 12, 30 cm down on hardness change

Current Problems:
This quick pit revealed a relatively subtle upside down scenario in the top 30
cm of the snowpack. The weak layer grain type is partly settled new snow. The
weather over the past 48 hrs has shown a gradual, not rapid, change in temps.
Center Ridge snotel between 1/11-1/13 climbed from an average of 27.5 to 32.2.
While this doesn’t fall into the “rapid” change category, it is enough of a
swing to create a change in hardness. Expect this weakness to be short lived.
We will track it in the coming days as precip tapers off and temps cool. There
is some potential for this lighter density snow to begin faceting and create a
more persistent problem in the future.

Future Problems:
We’ve also been tracking the presence of a melt freeze layer in the region.
12/30 was the last warm precip event and laid down a thick layer of wet snow up
to ~2000 feet, with rain in the lower elevations. This layer was not present at
2400′ on Tincan today. This layer will complicate our problems, where it
exists, in that it will support a lot of weight. It is up to 5″ thick in many
places. A layer like this will help the deep slab problem remain dormant for
potentially a longer period of time, and increase the complexity of forecasting
this particular problem.
We did not dig to the ground today, but full depth pits in previous days have
shown the November and October faceted layers intact, especially above 2000′.
While these layers have thinned as a result of large slabs compacting them, the
grains themselves are still angular and up to 3mm in size in many places. We
will continue tracking these weak basal layers for a long time.