Observation: Turnagain

Location: Turnagain Pass

Route & General Observations

Observed several new large piles of wet debris at the base of Seattle Ridge, as
well as some smaller crowns of wet slabs (D1-2s) that pulled out around 1200′
(see photos).

Very little field observations from above treeline in the past 24 hrs. We know
that the winds were high all day and that snow was falling above 1500′.

Rain on snow is a glaring red flag. Any time liquid water is introduced to a
relatively dry snowpack the existing structure of the snowpack is shocked.
After melting has occurred and freezing begins, the snowpack begins to
strengthen. Drainage channels have begun to form on the surface below treeline
(see photo). While this can be a good indicator for water draining out of the
bottom of the snowpack, this process just begun. This process can take weeks.
If H20 is able to effectively drain out of the bottom, the snowpack as a whole
can gain strength as the once saturated snowpack can now freeze as a more
homogenous mass. This might be good in terms of “healing” our weak base. There
are problems that make this hard to gauge. Knowing at what elevation the
snowpack has been fully saturated for one. Until we can see with our own eyes
the faceted grains fully melted and then frozen, we cannot trust this snowpack.
While this can be an encouraging sign we are still dealing with a deep slab
problem. Deep slabs do not play by the normal rules. Above treeline (rain/snow
line) this process has not occurred.

A quick pit @ 1100′ with temp profile revealed an isothermal snowpack. No
surprise here, given the sustained above freezing temps and rain hitting the
surface. Faceted grains at the base were wet but still recognizable as facets.

Photos & Video
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