Avalanche: Turnagain

Location: Bertha Creek

Route & General Observations

AAI/AAS Pro 2 class toured Bertha Creek drainage up to 2200′ to make field observations. Here is a quick synopsis of our snowpack observations.

Avalanche Details
If this is an avalanche observation, click yes below and fill in the form as best as you can. If people were involved, please provide details.
Trigger NaturalRemote Trigger Unknown
Avalanche Type Soft SlabAspect Unknown
ElevationunknownSlope Angleunknown
Crown DepthunknownWidthunknown
Vertical Rununknown  
Avalanche Details

We observed day old avalanche activity (soft slabs and dry loose) from the past day with spotty visibility/light, no new releases of today.
Our groups were able to get some small results on the new snow on moving short distances or on test slopes

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?No
Collapsing (Whumphing)?Yes
Cracking (Shooting cracks)?Yes
Observer Comments

Groups observed whumphing in the alders below treeline.
There were up to 3 meter shooting cracks (soft slab)

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

0930 at trail head - Broken skies, temps -8C, wind calm, no precip.
1300 @2200' - Winds picked up and visibility started to deteriorate. Some wind transport on terrain features at ridgelines and mid elevations.
1430 at trailhead - Overcast, temps, ~ -5C, wind calm, no precip.

Snow surface

Tiny surface hoar and near surface faceting on the surface of the snowpack to 1800'.
The storm snow had settled overnight and it was starting to show more cohesiveness.
Wind impacts on surface on some features.


We dug on the SW shoulder 1400-1700' at the entry to Bertha Creek in the end of the tour.
HS varied between 140 - 160 cm.
Buried surface hoar was at 30-40cm but was at 70-80cm depth on wind loaded features. Mixed results ranging from ECTN20 to ECTP11&12
Christmas Crust was at about 70cm. No ECT results nor problematic facets (one result PST 72/105 Arr on top of the crust).
Thanksgiving Crust Facet combo was about 105-115cm below the surface so out of reach to get good results with ECT or CT tests, but we did several PST's on this layer. Example results PST 16/115 End, 26/105 End, 39/115 End. These results show that the problematic structure still has plenty of propagation propensity if you happen to tickle it at a shallow spot.
The bottom of the snowpack is moist.

Photos & Video
Please upload photos below. Maximum of 5 megabytes per image. Click here for help on resizing images. If you are having trouble uploading please email images separately to staff.