Avalanche: Hatcher Pass

Location: Marmot, SW ridge and mid-rib

Date:
Observer:
Route & General Observations

Toured up SW ridge of Marmot to the mid-rib, to assess potential wind slab problem from Tuesdays ENE/E wind. Minimal wind effect was observed on S to W aspects at upper elevation. Few short cracks were observed in the upper 3-4″ of new snow. No collapsing or whumping was observed. From our limited tour inside a ping pong ball on Marmot today, we did not see any natural activity. We human triggered numerous small dry loose sluffs which will require sluff management skills and could carry consequences in steeper terrain.

Avalanche Details
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Trigger SkierAvalanche Type Dry Loose Snow
Aspect SouthwestElevation 3900ft
Slope Angle 40degCrown Depthunknown
WidthunknownVertical Run 50ft
Avalanche Details

We triggered numerous small dry loose sluffs in steep, 40deg+ terrain today above 3000'. In some locations, new snow dry loose are also entraining 1'+ of old loose facets in addition to last nights 6-8" of new snow, increasing the size and potential consequence of the avalanche. These sluffs are running reasonably fast making slope mitigation and management necessary in steep sustained terrain.

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

Today we observed minimal, small shooting cracks within the new snow.
We did not observe any whumping.
We triggered numerous small dry loose sluffs within the new snow, some entraining older weak facets.

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

New snow:
6-8" of new snow above 3000'

Temps and Wind:
10deg.F @ 10am, wind S 5mph G10 although it felt like 20-30mph gusts (we had to wear googles while digging pits)
8deg.F at 1pm, wind SSW 8mph G15
Obscured sky most of the day

Snow surface

3" of new snow below 2500'
6-8" of new snow above 3000'

Snowpack

We focused on assessing the upper layers in the snowpack after Tuesdays wind. On Tuesday, Feb 2 Marmot reported gusts ENE/E 25-30mph for 4 hours. Low density snow was available for transport. Minimal cracking in the upper 3-4" of snow, and no collapsing were observed today. We mostly focused on hand shears and pole tests today with limited results.
Overall: Poor structure, moderate to strong strength, low propagation.

The snowpack consists mostly of faceted snow, with 6-8" of new snow from 2/2-2/3.
HS varies greatly from 1 foot in wind scoured areas (now covered with a few inches of snow) to 7 feet in loaded aspects.
Test pits are pointing to less and less potential for propagation.

Minimal CT and ECT tests today were difficult to achieve propagation. Stormy weather and lack of visibility also made tests challenging to perform.

Overall impression: 2/2 Winds did not blow long enough or strong enough to build significant wind slabs on leeward, S to W aspects at upper elevation.

Photos & Video
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