Old Wind Slab on Mt. Bellview

Location: Paradise Divide Area
Date of Observation: 11/23/2017
Name: Turner Peterson
Subject: Old Wind Slab on Mt. Belliview
Aspect: South East
Elevation: 12,000′

Avalanches:

Saw this old avalanche that probably ran Nov 20th during the North winds, after the Nov 17th storm.

Weather:
Snowpack:

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Snodgrass obs

Location: Crested Butte Area
Date of Observation: 11/21/2017
Name: Alex Tiberio
Subject: Snodgrass obs
Aspect: North East, East
Elevation: 10,000

Avalanches:
Weather: Light snow with 1.5″ new overnight
Snowpack: The E/NE aspects held snow from October and this was noticeable in a couple quick hand pits. Crappy sugary snow below the more recent snow. Some whumpimg and shooting cracks near 10,000 feet. No reaction on a ski cut. Snow still quite thin hit several small rocks on descent.

Maritime in the Rockies

Location: Paradise Divide Area
Date of Observation: 11/20/2017
Name: Ben Pritchett
Subject: Maritime in the Rockies
Aspect: North East
Elevation: 10,600′
Tried to go hunting for a persistent slab problem in the Anthracites, but the snowpack was simply too thin to pose an avalanche threat.  Reversed course and drove to Rustler’s Gulch to see if the persistent slab problem existed around the Schofield Pass elevation.

Avalanches:

Observed several old avalanches, previously reported, off Baldy’s NE face into Emerald Lake.

Snowpack:

Pretty thin out there overall.  Generally 30-4ocm in most of the upper East River Valley.  Only very near Schofield Pass did we get into a deeper snowpack that averaged ~50cm.

The low snow levels at the beginning of the November 17th storm limited accumulations until the second half of the storm, when the graupel began to pile up!  During the beginning of the storm slashing rain fell in downtown Crested Butte, and here in the upper East River valley mixed rain and snow fell and formed a crust at the bottom of the storm snow.

The snowpack we observed at this site was “right side up” with, with no results in multiple snowpack tests.

Looking at the landscape, the Persistent Slab problem appears isolated across the mountain range, found only in a small proportion of the higher elevation Northly slopes of the Ruby Range and Schofield Pass area.

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Unstable snowpack were you can find old October snow.

Location: Paradise Divide Area
Date of Observation: 11/19/2017
Name: Evan Ross
Subject: Unstable snowpack were you can find old October snow.
Aspect: North East, East, South
Elevation: 9,700-12,300

Weather: Few Clouds, light west winds at Ridgeline.
Snowpack: A potentially unstable snowpack where old October snow was found at the bottom of the snowpack, and stable, supportive skiing on slopes that were dry before 11/17/2017.

On south and east slopes traveled. HS was in the 30-60cm range with only the 11/17 snow on the ground. No sings of instability. Ski pen around 5-10cm. Southerly slopes warmed with a soft crust in the afternoon.

On a northeast slope the snowpack structure looked poor. With the 11/17 storm snow sitting on faceted older snow. Depending on the aspect tilt, some of the those facets were capped by 1-3cm crust. The 11/17 slab had lots of Graupel mixed in, leaving the slab to look a little less cohesive then observed in other locations.

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Unstable snowpack where you can find old October snow.

Location: Paradise Divide Area
Date of Observation: 11/19/2017
Name: Evan Ross
Subject: Unstable snowpack were you can find old October snow.
Aspect: North East, East, South
Elevation: 9,700-12,300

Weather: Few Clouds, light west winds at Ridgeline.
Snowpack: A potentially unstable snowpack where old October snow was found at the bottom of the snowpack, and stable, supportive skiing on slopes that were dry before 11/17/2017.

On south and east slopes traveled. HS was in the 30-60cm range with only the 11/17 snow on the ground. No sings of instability. Ski pen around 5-10cm. Southerly slopes warmed with a soft crust in the afternoon.

On a northeast slope the snowpack structure looked poor. With the 11/17 storm snow sitting on faceted older snow. Depending on the aspect tilt, some of the those facets were capped by 1-3cm crust. The 11/17 slab had lots of Graupel mixed in, leaving the slab to look a little less cohesive then observed in other locations.

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Soft Slab avalanche on Baldy 11/18/17

Location: Paradise Divide Area
Date of Observation: 11/18/2017
Name: Stuart Griffin
Subject: Soft Slab avalanche on Baldy 11/18/17
Aspect: North
Elevation: ~11,000′

Avalanches:

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Remotely triggered from about 125′ away. Slide was about 50′ wide, ran approximately 150′. Crown size ranged from 1- 3 1/2′. Observed two other sympathetic slides. One of which was above original slide, unsure of distance run, but crown height appeared to be > 4′. Second observed slide was smaller in size, roughly 20′ wide with a 1-2′ crown height.

All of the above mentioned slides were all in wind loaded areas. Western side of northerly aspect.
Weather: Clear skies, N wind 10-15mph, Temp ~32*F
Snowpack: Unconsolidated with little to no base. Poor bonding between new snow and old snow. Basal Facets present on all aspects, also observed a lot of graupel mixed in with new snow. Lots of whumpfing, shooting cracks, very touchy snowpack.

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Touchy avalanche problem on northerly facing slopes

Location: Paradise Divide Area
Date of Observation: 11/18/2017
Name: Evan Ross
Subject: Touchy avalanche problem on northerly facing slopes
Aspect: North East, South
Elevation: 10,000-12,500

Weather: Clear sky and calm winds.

Gothic

Strange weather ending with a decent thunderstorm last night.  VERY dense snow averaging 13% water, though much of the storm it was at 16% with a total of 10½” new and water of  1.38″.  Strong overnight wind added to the overall fun.  Currently though calm and clear with 10″ of snow on the ground and the winter’s low at 4ºF.  billy

Old snow coverage before Nov 17 storm

Location: Paradise Divide area
Date of Observation: 11/15/2017
Name: Ben Pritchett & Eric Murrow
Subject: Old snow coverage
Drive through Kebler, Slate River Valley, Paradise Divide, Washington Gulch, Gothic Valley, around Crested Butte, and Cement Creek.

 

Thin and Isolated

Location: Paradise Divide Area
Date of Observation: 11/07/2017
Name: Evan Ross
Subject: Thin and Isolated
Aspect: West, North West
Elevation: 10,700-12,300

Avalanches:
Weather: Partly cloudy sky and generally calm winds with moderate gusts from the southwest. Enough solar to warm snow surfaces in low angled terrain and southerly facing slopes, mostly below 11,000ft.
Snowpack: Just a dusting of new snow from recent days. So, little change to the slowly developing snowpack. Thin and isolated would be my best short answer description of the current snowpack. Generally thin snow cover with isolated avalanche potential on wind loaded terrain. Snowpack structure is highly variable through the terrain. From bare ground or very thin snow coverage on southerly slopes, wind scoured on many south westerly to westerly slopes, to just a thin snowpack on the other aspects. There is very little to no snow on all aspects below 10,500ft. The deepest snowpack could mostly be found on northwesterly to north facing slopes above treeline that are either protected from the wind or have seen additional wind loading during previous storms. Faceted snow from October is the weak layer at the bottom of the snowpack and can be found where it hasn’t been blown away or previously melted by the sun. Find a thick enough slab on top of this week snow and you’ll have found a potential avalanche problem. These two ingredients looked to mainly line up on wind loaded terrain. Such as, cross loaded gullies on westerly aspects or wind loaded pockets on northerly and easterly aspects.

 

Northwest facing bowl on Mt Baldy. Westerly facing slopes completely blown off with northeasterly have more continuous snow coverage and wind loading.

 

WSC Bowl? Westerly facing bowl near Paradise Divide on Mt Baldy. The deepest and most suspect looking snow coverage was in this area on north to northeast aspects of this bowl.

 

Looking up Rock Creek past Cinnamon Mountain and toward Treasury Mountain.

 

October snow is faceted and week at the bottom of the snowpack. Add enough snow on top of these facets and you will have found the lone avalanche problem. North to northeast aspects were the most suspect with current snow coverage.

 

Looking at northeasterly to east facing slopes on Purple Ridge.

 

View from Paradise Divide toward Mt Richmond.