| Recent Avalanches? | Yes |
| Collapsing (Whumphing)? | No |
| Cracking (Shooting cracks)? | Yes |
Observation: Turnagain
Location: Silvertip
Ascended N ridge of Silvertip to about 3000′ via Silvertip Creek drainage. No obvious signs were observed within this drainage. There was recent wind slab avalanches one ridge over on a NE aspect (observed yesterday from Johnson Pass trail head.) Old debris was observed in many steep and/or channeled terrain features, all from past storm cycles.
Obvious signs of instability
Observer Comments
Small localized cracking under foot, no shooting cracks in 4" wind slabs between 2500-3000' along the N Silvertip Ridge.
Weather
Sunny with thin cloud cover
5F - 0F
Winds were calm until and ~3pm and could feel light East breeze
No recent precip
Snow surface
8" of loose settled snow is sitting on a firm melt/freeze crust to about 1600'
Light wind skin until ~2000' transitioning into stiffer 2-4" thick hard slab/sastrugi above.
Snowpack
Dug a pit at 2500' on 25 degree slope on a NNE aspect along Silver tip ridge in a wind loaded area that was supportable and hallow sounding. The height of snow 275cm and average depth in this area was 180cm. Our pit was only 90cm deep, we did not dig to the ground. We found a 4" hard wind slab that failed on isolation in Compression Test and propagated with only 4 taps in Extended Column Test. The snow was 4F hard just below this layer. We found the Feb.9 buried surface hoar layer 65cm below the surface which failed in Compression test with strong force (CT25) and did not fail in ECT. The buried surface hoar was between 3-5mm in size and was not standing up in pit. It was sandwiched between two pencil hard layers.
Sastrugi and hard wind slabs were the norm above 2000' along Silvertip's N ridge
Light wind skin on SW aspect starting around 1600'
A few soft turns to be found on NE aspect below 2000'
A view looking back at the SW facing slope adjacent to N ridge of Silvertip, no recent avalanche activity was seen on this aspect
This is the opposite side of ridge in the opposite photo, taken from Johnson Pass trail head. Several large wind slabs were observed yesterday
NE facing slope of Twin Peaks, no recent avalanche activity noted, just a pile of old debris in channeled terrain from a previous storm cycle
Wind slab that failed on isolation of a compression test at 2500'. The snow below this hard slab was very loose and soft
Feb.9 buried surface hoar layer was found 65cm below the surface at 2500'
Buried surface hoar was 3-5mm in size
Looking at the N face of Silvertip peak in the back of Silvertip creek drainage