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Avalanche: Summit

Location: Manitoba

Date:
Observer:
Route & General Observations

Route:
Manitoba to 3400’

 

Avalanche Details
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Trigger NaturalAvalanche Type Soft Slab
Aspect EastElevation 3800ft
Slope AngleunknownCrown Depthunknown
Width 1500ftVertical Run 1500ft
Avalanche Details

We think this avalanche - pictured below - occurred around 3 pm in the bowl to the east of Fresno peak, during a period of fairly intense snow transport. Despite propagating across nearly the entire bowl - granted well below ridgeline - the debris was fairly limited (~D2... maybe D2.5), making us suspect this wasn’t nearly as deep as the slides from late last week. We didn’t see tracks near the ridge to the south, so suspect it to be a natural.

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)?Yes
Cracking (Shooting cracks)?Yes
Observer Comments

Red flags:
Recent avalanche activity: yes, as reported in that ob.
Collapsing: yes, one that propagated a ways down the NW ridge that runs to the summit
Cracking: Yes, localized along the NW ridgeline, with cracks shooting ~20’ in the recently wind deposited snow.
Blowing Snow... Oh yeah! Light snow transport and wind affect on slopes above treeline, with tracks filling in from moderate snow transport above 3300’ and along the NW ridgeline that leads to the summit. Moderate to intense snow transport observed on neighboring peaks throughout the day.

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

Broken -> few clouds as the day progressed
Temps teens down low and single digits up high.
Light N winds occasionally gusting moderate above treeline, with the exception of some mid-afternoon sustained moderate N winds right at the NW ridgeline below the summit. Winds appeared to die down by late afternoon.

Snow surface

Despite wind activity, the surface remained fist hard at all locations on our tour except just on the ridgeline, where small areas of soft slab up to 18” deep were deposited. Ski penetration of 3-6” - less up high - and boot penetration of 12-24”

Snowpack

No formal stability tests.

Photos & Video
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