Observation: Summit

Location: Summit Mountain

Date:
Observer:
Route & General Observations

Ascended up the SE face of Summit mountain to gain the NE ridge up to 3800′. Skied 3 laps on N and NW aspects in the first back bowl. Skied out via NE ridge to the SE face. Lots of wet loose avalanche activity in the late afternoon on S & SW aspects in Summit Area. Wet loose activity on SE aspect of Summit. Snow conditions ranged from melting snow over supportable crust, knife hard crust, to low density powder.

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

Dozens of natural wet loose avalanches across the Summit Area on S & SW aspects in late afternoon. Wet loose point releases from steep starting zones on SE aspect of Summit (unsure if new or old). Old roller balls on steep solar aspects of Summit noted from previous days.

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

Temperatures ranged from 37 F to 45 F in valley bottoms and from 28 F to 33 F at ridgetops during our tour from 10:30 am - 7:30 pm.
Winds were calm most of the day with the exception of light NW winds in the afternoon.
Clear skies.
No precipitation.

Snow surface

During our ascent on SE solar aspects we found 2-4" of soft, melting snow over a supportable crust at lower elevations that became knife hard crust on steep aspects at higher elevations. By our descent at 7 pm this has changed to a mostly supportable crust, with melted snow the last 200' to the road.

On N, NE, and NW aspects we found on average 8" of low density powder. Near ridgelines the depth of new snow was as little as 2" and ranged to as much as 1' in wind loaded areas. Despite the wind distribution, the snow was low density and we could not find a slab.

Snowpack

We focused our assessment on what was happening between the new and old snow interface.

N and NW aspects in bowl: The average of 8" of low density powder rested over either: a 1.5" supportable melt freeze crust at the top of the back bowls, transitioning to sitting over a few cms of facets over a breakable melt freeze crust that varied in thickness below 3300'. Pole probing and digging deeper revealed more facet/crust combos to the ground.

NE aspects: Along the ridgeline 6" of powder sat over the ground or a thin, breakable melt freeze crust/facet combo. On the NE face in the trees we found 6" to 1' of low density powder over a very thin, breakable melt freeze crust/facet combo. Hip deep boot penetration.

SE aspects: 2"-4" of of sun baked snow sits over a supportable to knife hard melt freeze crust. The melting surface snow locks up into supportable crust in the evening.

Photos & Video
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