Avalanche: Summit

Location: Raven's Ridge

Route & General Observations

We toured up to Raven’s Ridge to see how the wind was affecting the snow and how the January facets are behaving in Summit Lake. It was windy and there was a variety of wind affected surface conditions even in the treeline elevation band. We did not get any concerning results in our snowpit, but we still think that there’s a chance a person could trigger a large avalanche on the weak snow from January that is about 1-1.5’ down from the surface in Summit. It hasn’t yet been a week since there were two large avalanches observed on Butch Peak and near Crescent Lake that we believe failed on the January facets. This layer is gaining strength, and we will keep tracking it. I watched a wind slab avalanche in motion on my drive from the active wind loading from the northwest so wind slabs were at the top of the list of things to watch out for today.


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 UnknownAspect Southeast
Elevation 4000ftSlope Angleunknown
Crown DepthunknownWidthunknown
Vertical Rununknown  
Avalanche Details

I watched a natural avalanche in motion on Gilpatrick mountain as I was driving. There was active wind loading from the northwest when this occurred.

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?Yes
Collapsing (Whumphing)?No
Cracking (Shooting cracks)?Yes
Observer Comments

I watched an avalanche in motion on the southeast face of Gilpatrick mountain as I drove to Summit Pass. Snow was blowing off the ridgelines from the northwest. The wind seemed to change direction throughout the day so many different aspects were being actively loaded. I got a shooting crack when I jumped on a small wind loaded test slope at about 1,800’.

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

It was partly sunny, windy and cold. Temperatures were about 15 F at the car and there was strong wind on the ridgetops mostly from the northwest, but there were times when we noticed it was blowing from the south on Raven’s Ridge.

Snow surface

At the parking lot there was a thick crust below 6-8” of soft new snow. At 1,300’ the crust was 6” thick with 6-8” on top. At 1,350’ we noticed a sun crust on a small steep south facing slope that was a few inches thick. The sun crust only existed on steep south facing slopes. As we came out of the trees there was a variety of wind affected surfaces including soft sastrugi, wind texture, and wind slab several inches thick.


We dug a pit at 2,600’ on a west aspect where the snowpack was 4.8’ deep (115cm). The interesting layers included a 2” (5cm) wind slab on top, the President’s Day crust 6” (15cm) down, and the January facets about 1.3’ (40cm) below the surface. It was hard to tell where this layer ended and where the layer below it began because they were all rounding facets that were 1F hard. We did not get any concerning test results (CT1 PC 5cm down below wind slab, CT30 RP 40cm down on Jan facets, ECTX). The President’s Day crust didn’t have any facets surrounding it yet, which was good to see. The January facets were 4F-1F hard but were very loose and dry when we pulled them out of the snowpack. They were rounding and connecting in places when we looked through the scope so these are positive signs that we will keep tracking.

Photos & Video
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