Observation: Turnagain

Location: Sunburst

Date:
Observer:
Route & General Observations

Sunburst to 2350′

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)?No
Observer Comments

Widespread collapsing was observed above 2000'. These events were frequent and traveled far in a few locations.

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

Temps: Mid to high 30's F
Wind: Moderate (10, g 25mph)
Sky: Obscured
Precip: Moderate precip
Rain/snow line: 1500'

Snow surface

1000': 10" of wet saturated snow with 8" puddles of water
1500': 10" of wet mashed potato sticky snow w/ an inch of drier snow on the surface (gloppy skinning conditions.)
2000' - 2350': 1-3" of new snow on 1" melt/freeze crust sitting on the St.Patty's Day Slab

Snowpack

Slab depths varied from 12-18". We dug a pit at 2350' and found a very poor structure of 4 Finger hard facets sitting below a 4F-1F hard cohesive slab. Out test results were very easy with high propagation potential. (ECTP1 (SC) and ECTV (SC)

Considering the snowpack history over the last week widespread collapsing and easy test results are no surprise. Several feet of new snow is now covering up last week's faceted snow that was created from a week of 0F temps. This weak layer of facets varies in density due to moderate winds that accompanied the cold snap. However these facets are widespread throughout Turnagain, Girdwood, Summit, and Portage, and could be reactive at all elevations and aspects. This faceted snow will be less developed on ridges that were left scoured before the St.Paddy's storm. Digging a pit in these areas might not be representative of the slope you are thinking of skiing/riding. This is a great reminder that obvious signs like collapsing or recent avalanche activity trump snow-pit data. These clues are the snowpack's way of saying; Stay away from steep terrain. In the upper elevations average slab depths are likely to be closer to 3' with leeward features up to 6' thick. Between 2000 - 2500' a layer of melt freeze crust has formed just below the surface snow and below 2000' the snow is wet and saturated. If/when temps drop below freezing mid-elevation snowpack should stabilize quickly as it freeze into a dense melt/freeze crust.

Photos & Video
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