Avalanche: Portage / Placer

Location: Grandview - South of Placer Valley just outside the forecast zone

Date:
Observer:
Route & General Observations

Rode in the Grandview region today. Noted several old and some new(ish) large slab avalanches from the recent storm cycle and wind event yesterday 2/23. Also noted two fresh slabs that appeared to have been remotely triggered from some distance away. The smaller of the remote triggered slabs is just up-ridge of the site of the double fatality ten years ago on Feb 13th, 2010. That report can be found at the link below and on our accident page:
www.cnfaic.org/accidents/grandview-mile-45-alaska-railroad

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 UnknownRemote Trigger Yes
Avalanche Type UnknownAspect East
Elevation 3000ftSlope Angleunknown
Crown DepthunknownWidthunknown
Vertical Rununknown  
Avalanche Details

One very large slab avalanche (E facing ~3000') and one large slab (E facing ~2,200') were seen from the flats in Grandview today (Feb 24). These we found out later were remotely triggered from quite far away. They look to be 3-4+' thick and likely released on the old buried January faceted snow that has been the culprit in the many large slabs seen during the past week.

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)?No
Observer Comments

Recent avalanches. We stayed in the flats away from avalanche terrain.

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

Sunny and cold. Temps were in the single digits.
Easterly winds along ridgetops were creating some plumes on the higher terrain.

Snow surface

2-3' of settled storm snow from the past week. Excellent riding conditions. Again, we stuck to the flats at an elevation between 800-1200'. Wind effect was evident in the higher terrain.

Snowpack

We dug one quick snow pit to see how deep the weak January faceted snow was buried.
1,000', east aspect, snow depth ~250cm (8 feet)
January facets sit around 125cm (5 feet) deep. No tests performed. The slab on top is right side up, going from very soft power on top (fist hard) to 1 finger hardness above the facets. The facets were around 4 finger hard and intermixed with degrading old crusts.
Other than the January facets buried so deep, no other signs of instability were noted in the top 5 feet at the lower elevations.

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.