Observation: Girdwood

Location: Notch

Date:
Observer:
Route & General Observations

Toured up to 2500′ to take a look at the upper snowpack ahead of the next round of precip and winds. It looks like the 1/10 storm rained almost all the way up the road, and there was a breakable crust just below the snow surface up to about 1800′. I dug at 1400′, 2200′, and 2500′, finding around 2-4″ new snow in the lower pit, 8-10″ new snow in the middle pit, and close to 3′ of wind-loaded snow in the upper pit. Stomping around on steep rollovers, I was able to get some shooting cracks but could not get anything to move. I got propagating stability test results in the upper pit, one in a low-density storm layer about 16″ deep, and another on top of the New Year’s crust about 30″ deep. These two weak layers will be the two layers of concern as the next round of snow and wind moves in.

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

I was able to get some shooting cracks on steep, wind loaded rollovers.

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

Cloudy skies with temps right around freezing at 1400'. Moderate easterly winds were increasing slightly during the afternoon, with light snowfall not amounting to any significant precip. Visibility was in and out, with the upper ridgelines socked in at times, and great views across the Girdwood Valley at other times.

Snow surface

Variable. Heinous breakable rain crust up to 900'. Slight dusting of very sticky snow on top of the crust up to about 1800'. Increasing depth from 1800' to 2500', with average new snow depths around 6-10" by 2500'.

Snowpack

See attached photos for more snowpit info.

I dug pits at 1420', 2200', and 2420' down to just below the New Year's crust. In each pit, the weakest interface was a layer of low-density stellars from the beginning of the 1/10 storm, and the second weakest layer was a layer of facets right on top of the New Year's crust. Both of these layers propagated (poor stability) in the upper pit, and neither propagated in the mid pit. I was able to get some shooting cracks on wind-loaded rollovers, but the wind slabs did not feel like they had much energy, and I couldn't get anything to move.

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.