Lots of activity

CB Avalanche Center 2018-19 Observations

Location: Paradise Divide Area
Date of Observation: 11/23/2018
Name: Steve Banks

Subject: Lots of activity
Aspect: North East, East
Elevation: 9,400-10,400

Avalanches:

We saw a lot of activity in this location. Lots of cracking and slumping and numerous avalanches triggered remotely. None were very hazardous (R1-D1) and the biggest one ran about 100′. What surprised me the most was the remote triggering. We triggered several slides from 200′ or more away. Slopes in the mid 30 degree range would crck and move slightly. It seemed the slope needed to be 40 degrees or steeper today to get the momentum to move.

Weather: Lovely winter day. Temps in the mid to high 20’s with calm to light winds. Overcast and snowing all day. Mostly S2 with periods of S1.
Snowpack: Generally 9-12″ of new snow overnight. Bottom half of the new snow was slightly more dense (4f) than the surface snow (F). Very weak facets below (F-). On steeper slopes with more Easterly tilt there was a soft, decomposing crust within the old snow, but this was intermittent. In some areas the facets at the ground were moist, some places frozen back together, and some places totally dry. In general there is little cohesion or slab in the snow, though apparently there is enough to form avalanches!
A quick Shovel Test showed Easy (7) results failing below the new snow on the facets with Resistant Planer shear.

Photos:

 

Touchy storm slabs in the Paradise Divide zone

CB Avalanche Center 2018-19 Observations

Location: Paradise Divide Area
Date of Observation: 11/23/2018
Name: Alex Banas

Subject: Touchy storm slabs in the Paradise Divide zone
Aspect: North East, East
Elevation: 10,000′ – 11,000′

Avalanches:

SS-ASc-R2-D1.5-I This soft slab avalanche propagated from 30* terrain through a gully feature and onto the adjacent slope.

Weather: Overcast. Snowing S1 . Moderate winds from the West.
Snowpack: Today we observed widespread cracking and collapsing on E-NE terrain around 10,500′. Shooting cracks out 20+m. HS varied from 40-95cm. It was a weak over very week set up with the snowpack failing on facets at the interface of the new and old snow, mostly on an old faceted out crust. Storm Slabs varied from 20-45cm thick.

Photos:

Storm observations from Upper Slater River Valley

CB Avalanche Center 2018-19 Observations

Location: Paradise Divide Area
Date of Observation: 11/23/2018
Name: Eric Murrow & Evan Ross

Subject: Storm observations from Upper Slater River Valley
Aspect: North East, East, South East
Elevation: 9600′ – 11100′

Avalanches:

We skier triggered 4 Storm Snow avalanches, one of which was remotely triggered and was likely a D2 in size. Poor visibility and trees prevented viewing the debris.
A group riding earlier the morning in same terrain triggered a D1.5 as well.
We also saw two natural avalanches, D1.
All observed avalanches failed at the new/old interface and where easterly to northeasterly facing.

Spoke with a group of skiers, that ascended a ridge just adjacent to our up track, that said Purple Palace terrain had avalanched in multiple places. I did not view this terrain, but based on the slope size in this area these avalanches were likely close to D2 in size.

Weather:

Skies were overcast with light snow from 10am to 3pm, generally S1 snow with brief periods of S2. On our below tree line tour, winds were light with occasional moderate gusts. Visibility was poor but did see small amounts of snow transport.
Snowpack:

On the way out Slate River Valley, we stopped at Pittsburg, 9400′, at 1050am to measure the new storm snow and found 10″ of new snow with .8″SWE. On the way out we stopped back at Pittsburg at 315pm and measured 11.5″ storm total with .95″SWE. Much of the new snow was rimed particles with some graupel present.

On our tour we found new snow totals ranging from 10″ to 15″. The new snow was resting on very weak old snow on any aspects with even the slightest bit of north to it. The new snow was very reactive to the weight of a person. We triggered 4 slides, saw one other human triggered slide, and two natural slides. Mostly D1.5 in size, given the generally small terrain features we were on. I imagine that on larger slopes avalanches would have reached D2 in size (large enough to bury a person). Several of the avalanches were triggered remotely from 75′ to 100′ away; impressive for storm snow that was fist dense(very soft). We descended east facing terrain back to snowmo’s and saw cracking within the new snow on descent that wasn’t present while ascending. The storm snow was sitting on melt/freeze crusts  and large facets on this east aspect.

At the end of the day, we rode machines part way up Paradise Divide road until we were shut down by soft, large drifts up to 4′ thick on the road surface. On our tour we saw minimal evidence of loading below tree line, but riding up the road through the open the impact of the wind was obvious.

Photos:

Gothic 7am Weather Update

CB Avalanche Center 2018-19 Observations

Location: Kebler Pass Area
Date of Observation: 11/23/2018
Name: billy barr

Subject: Gothic 7am Weather Update
Aspect:
Elevation:

Avalanches:
Weather: Light snow in the afternoon picking up for an hour or so late afternoon, then light off and on snow overnight with steady wind. Currently obscured with steady moderate wind and light snow. New snow of 4″ with water 0.26″ and snowpack at 8″. Decent snowfall is very unusual with steady wind here and that has been the case overnight. billy
Snowpack:

Photos:

Schofield Pass tour

CB Avalanche Center 2018-19 Observations

Location: Paradise Divide Area
Date of Observation: 11/22/2018
Name: Eric Murrow

Subject: Schofield Pass tour
Aspect: North, North East
Elevation: 10300′ – 11,7500′

Avalanches:

Triggered a small Persistent Slab near treeline on a north aspect at 11,750′. It was only about 20′ wide but ran about 600′ vertical. I was able to easily ski off slab as it released.

Weather: First snowflakes dropped at about 11am with consistent accumulating snow at about 2pm. Winds remained light even neat treeline through 3pm.

Snowpack: Same ol’….weak snow surfaces (facets and surface hoar) and really just plain weak in most places. One drifted near treeline pocket clearly contained a small old slab.  Snow depth ranged from 30cm to 60cm across most terrain.

Photos:

Snow/Wx Obs before the next storm comes

CB Avalanche Center 2018-19 Observations

Location: Paradise Divide Area
Date of Observation: 11/21/2018
Name: AR

Subject: Snow/Wx Obs before the next storm comes
Aspect: South West, West, North West
Elevation: 11,000′-12,800′

Avalanches:

On a SW aspect of our descent, we had one small point release from the edge of a turn. New snow slid on the uppermost crust layer, but did not propagate and ran only about 50 feet. This point moved very slow, but did illustrate the potential for the newer deposited snow to slide on the crust below it, especially on aspects that have received solar radiation. As new snow accumulates with the forecasted Thanksgiving storms, this weak layering structure will become more reactive, with more fresh snow on the crust, and potentially on the lower crust or facets deeper in the snowpack.

Weather: Clear, calm weather. Steady mild temps throughout the day 26-30F, no clouds, no wind.
Snowpack: Our party of two toured on a western facing slope from 11,000′ to a ridge at 12,800′. The snow depth was variable depending on the terrain, ranging from 10-20 cms in the wind scoured upper chute to 80-90 cms in the open bowl below. We found a generally weak snowpack structure with little to no slab in most locations, though a prominent crust was present mid-pack shortly after we gained elevation from the valley floor. Digging two snow pits between 12,000 and 12,500 we found multiple crust layers mid-pack. The structure of the bottom of the snowpack was weak faceted snow, topped by 2-3 crust layers dependent on the aspect, topped by fresh and freshly wind deposited snow. SW or WSW aspects that had more solar exposure prior to last week’s storm cycle had a stronger crust. W and WNW aspects had a less defined crust. In shovel shear tests the weakest layer appeared to be between the crusts and popped fairly clean on a large facet layer between the crusts. Though we found and isolated the weakest layers, this layer did not propagate in ECTs, and with the variable structure due to terrain features, we found no slab or concern of propagation.
The surface of the snow was very soft for skiing, with few pockets of wind-stiffened snow.

Photos:

Pre-storm snow surface look around

CB Avalanche Center 2018-19 Observations

Location: Paradise Divide Area
Date of Observation: 11/21/2018
Name: Eric Murrow

Subject: Pre-storm snow surface look around
Aspect: North, North East, East, South East
Elevation: 9400′ – 11600′

Avalanches:

There were numerous old, dry loose avalanches from the past weekend on a steep northeast facing terrain feature. Very small in size.

Weather: Clear skies, mild air temps, and calm winds.
Snowpack: Ascended from Pittsburg up underneath the east side of Schuylkill Peak. While ascending below treeline snow surface on north and east aspects were dry and weak with remnants of patchy surface hoar laying flat. A pretty poor surface for an incoming storm to fall on. As we transitioned towards Southeast the snow surface transitioned to a wet surface. These Southeast and south slopes had a thin layer (3cm) of moist facets sitting on an old melt/freeze crust. Later in the afternoon while descending this snow was beginning to refreeze and will likely be a slick crust as the new storm comes in. None of these surfaces will likely bond well to the incoming storm.
As we ascended higher, up to 11600′, the snowpack remained weak and faceted on north and east aspects with no current slab structure. On southeast slopes near tree line the snow surface remained dry and weak. Only slopes that were very near due south had a melt/freeze crust at the surface at this elevation.

Photos:

CB Avalanche Center 2018-19 Observations

Location: Paradise Divide Area
Date of Observation: 11/19/2018
Name: MR

Subject:
Aspect: North, North East, South, North West
Elevation: 10,600-12,700

Avalanches: None
Weather: beauty day. Strong afternoon winds out of the Northwest ish transporting snow off ridge lines.
Snowpack: 4-6 inches of new snow from Saturday night on top of mostly faceted snow down to the ground in most Northerly spots. Stubbornly breaker suncrust on one high southerly aspect that we had to navigate to get back on the aspects we wanted to ski.

On North facing terrain, above where the snowplug forms below Emerald Lake, at around 12,000 feet, we did find a pretty widespread old layer with new slightly wind-stiffened snow on top, with several avalanches at most r1-d1 that I would assume ran on sunday.

Steve Banks threatened to not heart my instagram posts if I didn’t submit an observation. This is the sort of strong-arming tactic the bullies at CBAC will use on you if you don’t submit your observations! Just, you know, fair warning.

Photos:

Variable, Weak, Sharks

CB Avalanche Center 2018-19 Observations

Location: Paradise Divide Area
Date of Observation: 11/19/2018
Name: Evan Ross, Eric Murrow

Subject: Variable, Weak, Sharks
Aspect: North East, East
Elevation: 9,700-12,800

Avalanches:

Just some small loose snow avalanches in steep or wind-loaded terrain.

Weather: Light west northwest wind at ridgeline. Otherwise just a standard clear and cool Colorado day.
Snowpack: Variable, is that best word to start with when describing the current snowpack. Both snow surface and snowpack structure are variable.

For now, the snowpack structure is beaten and weak. On the northerly and easterly aspects, we traveled today, its hard to say where you could find some “persistent slab” structure. Generally, the snowpack is full of weak layers with crusts and facets, while the actual slabs are much harder to find. If you do find a small slab and set it in motion, that would be a small bummer, but the available loose weak-snow that could be entrained would add to your current bummer experience. This bummer of a time could become a bummer for the rest of your season if the whole mess pushed you into those lurking rocky sharks. That would be a total bummer.

The snow surface is also a mess. If you stay away from the wind effected snow surfaces then the skiing sure is nice for what it is. Otherwise, those snow surfaces are also weak or crusty and fit right into what you would expect for a standard  poor start for a continental snowpack. New snow amounts from last weekend range from 4cm’s up to 20-30cm’s on some wind-loaded terrain. Most of the wind pillows we found were old with a skiff a new snow on them and not an issue, but we did avoid one or two pillows that may have been thicker. If you did find a slab in the upper snowpack from last week’s new snow, the facets and crusts that it was likely sitting on would not instill confidence. Small loose snow avalanches in the new snow and some gouging into the older snow were also observed.

Photos:

Halloween Bowl Paradise Basin

CB Avalanche Center 2017-18 Observations, 2018-19 Observations

Location: Paradise Divide Area
Date of Observation: 11/17/2018
Name: Andrew Pearson

Subject: Halloween Bowl Paradise Basin
Aspect: North, North West
Elevation: 11800

Avalanches:

There has been two avalanches in Halloween Bowl out Paradise divide this year. The one witnessed happened 11/17/2018. It was human triggered and broke off in an area filled with trigger points. It didn’t propagate far and did not go all the way to the basin floor. I would call it and R2 D1 slide. The slope angle at and around the crown was 35+ and strictly N aspect. I would imagine that it failed on the faceted weak layer based on the pit I dug, which was right next to the slide same aspect and slope angle.

Weather: Clear, Partly Cloudy. Temperatures stayed around and below freezing majority of the day. Winds in the bowl were light. No precipitation (valid through 3pm).
Snowpack: Snow depth varying depending on wind deposit, but consistently around 70-80 cm in the deeper areas, where the avalanche occurred. In the pit I dug at 55cm was a prominent weak layer with faceted snow. On top sat a more consolidated slab about 20-30 cm deep. Top slab was about four fingers whereas the next layer was fist and rotten. When doing a CT test, There was failure at 55cm at 15 making it a CTM.

Photos: