Gothic Area and Fresh Wind Slabs

CB Avalanche Center2019-20 Observations

Location: Crested Butte Area
Date of Observation: 01/14/2020
Name: Evan Ross
Subject: Gothic Area and Fresh Wind Slabs
Aspect: North East
Elevation: 9,400ft-10,200ft

Avalanches: Couple of fresh wind slabs to D2.5. The spork ran this morning, while the others in the last 12 hours.

Gothic Mountain, The Spork. SE terrain, but the slab pulled from the cross-loaded easterly facing portion of the start zone. This path has run multiple times this winter so it doesn’t have the full seasonal snowpack. Crown estimated to be near a meter deep and releasing around the old snow surface. SS-N-R2-D2.5

Gothic Mountain, East Face. E, 12,500ft. Fresh wind slab that propagated slightly wider lower in the bowl. SS-N-R2-D2.5

Rustlers Gulch, SE, 12,600ft. Estimated D2 slab, but viewed from very far away with little detail.

Weather: Few Clouds, light wind down low with continued snow plums off the high peaks through the day.

Snowpack: Expected to find some concerns with cross-loading, but in the end, no new slab issues were found. Maybe higher in the terrain, there was something more concerning. At 10,000ft on northeasterly facing slopes, faceted grains were down about 18cm. The new snow wasn’t concerning, above the old snow surface from last week. It simply added to the loose snow avalanche potential or could release as a very soft slab in very steep or unsupported terrain. Deeper new snow accumulations or cross-loading at slightly higher elevations could have created more of a slab concern. If SH was present in this snowpack, it was surrounded by other weak faceted grains and not a layer of concern.

HS was in the 90-120cm range. Old persistent slab structure could still be felt lingering in the snowpack. This structure wasn’t making any noise or showing obvious signs of instability. While the majority of the most concerning terrain features in this area had previously avalanched this season with old crowns still visible.

Avalanche Obs from Slate Sled and Truck Tour

CB Avalanche Center2019-20 Observations

Location: Crested Butte Area
Date of Observation: 01/14/2020
Name: Eric Murrow
Subject: Avalanche Obs from Slate Sled and Truck Tour
Aspect: North, North East, East, South East, South, South West, West, North West

Avalanches: A substantial number of avalanches observed around Slate River Valley and terrain visible from roadways around Crested Butte. Natural avalanche activity was largely a product wind-loading from the last storm at upper elevations. Do not believe I spotted any below treeline avalanches today. Most avalanches appeared to only involve the recent storm snow from the past 5 days, propagation was fairly limited. A number of these avalanches are repeat offenders that failed earlier in the winter. One avalanche in Axtel’s Green Lake Bowl failed sometime between 3pm and 440pm. Avalanches up to D2 in size were observed off Scarps Ridge(NE), Redwell Basin(NE,E), Peeler Basin(NE), Schuylkill Ridge(NE), Cinnamon Mtn(S), Angel Pass(NE), Purple Ridge(S), Gothic Mtn(E,SE,SW), Mount Bellview(S,E), Red Ridge(S,E), WSC Peak(S), Deer Creek(S), Teocalli(debris in SE gully), Whetstone’s Hidden Lake Bowl(NE), Axtel’s Green Lake Bowl(NE). See photos for a selection of observed avalanches.

Weather: Mostly clear skies. Cold temps in the morning at valley bottom quickly warmed up before noon. Winds at valley bottom were light, but lots of flagging off ridgetops and summits all day long with continued loading for near and above treeline slopes from southwest winds.

Photos:

Another human triggered avvy

CB Avalanche Center2019-20 Observations

Location: Kebler Pass Area
Date of Observation: 01/13/2020
Name: Pat
Subject: Another human triggered avvy
Aspect: South East
Elevation: 9500′

Avalanches: Triggered a small but deep slab avalanche on a steep and short roll at the very end of the Ponytail Glades descent just above the Kebler trailhead. Depth of slab appeared to be about 2 feet, and it broke on a very pronounced layer, presumably the surface hoar layer about 70cm deep. This activity reflected our observations while skinning up: early in the morning, the snow in this spot was soft and consistent. At the top of Ponytail, we observed whumphing and shooting cracks as we traversed into westerly-facing wind-affected aspects. Upon reaching the location of the avalanche, our previous skin track had been entirely scoured away, and this was where the trigger occurred.
 
Weather: Calm, snowy in the morning around 10-11am, with increasing winds from the west around 12-2pm.

Snowpack: Soft, light, consistent 1 ft of dendrite pow in the morning, and heavier with a wind crust in the afternoon.

Photos:

Small skier-triggered avalanche from 1/13

Human triggered avalanche

CB Avalanche Center2019-20 Observations

Location: Kebler Pass Area
Date of Observation: 01/13/2020
Name: Sam
Subject: Human triggered avalanche
Aspect: North East

Avalanches: Triggered small pocket on steep wind loaded roll, broke as a slab in the storm snow but ran as loose dry sluff
 
Weather: Cold, snowy, windy. Snowed roughly two inches through out day, heavy winds from north west actively loading throughout the day.

Photos:

anthracites storm instabilities

CB Avalanche Center2019-20 Observations

Location: Kebler Pass Area
Date of Observation: 01/13/2020
Name: MR
Subject: anthracites storm instabilities
Aspect: North, North East
Elevation: 11,000

Avalanches: See photo. Looked to be skier triggered. On the bottom steep roll skier’s right at the bottom of big chute where it tends to do that. R1D1 soft storm slab. The storm snow in the middle of big chute had also run when we got there, presumably triggered by the first skiers as well. No other propagating avalanches observed but plenty of cracking and stuffing in the storm snow.

Weather: Blowing, snowing, and cold all day.

Photos:

Anthracites Storm Check and Touchy Surface Hoar Layer

CB Avalanche Center2019-20 Observations

Location: Kebler Pass Area
Date of Observation: 01/13/2020
Name: Eric Murrow & Zach Kinler
Subject: Anthracites Storm Check and Touchy Surface Hoar Layer
Aspect: North, North East, East
Elevation: 9,200′ – 10600′

Avalanches: Visibility was poor looking into alpine terrain but spotted several small slabs on easterly facing terrain below treeline, D1’s. Intentionally triggered a Persistent Slab avalanche on a NE facing slope at 10600′ on a buried surface hoar layer, D1.5.

Weather: We spent the afternoon out Kebler Pass from 130pm until 4pm. During this time winds had relaxed blowing only lightly below treeline but evidence of strong winds was obvious from early in the day. Snowfall was generally light with 3/4″ accumulation from 2pm to 4pm. Skies were often obscured and mostly cloudy.

Snowpack: We poked a hole on a NE facing slope at 10600′ at the Anthracites and found HS ~210cm. It was a little difficult identifying snowfall from the past 24 hours but as of 330pm it looked like 36cm (~15″) with .65″SWE….ya it was pretty blower. During test profile an obvious Surface Hoar stripe was found 70cm down (suspect this layer was buried on the evening of 1/8), results on this layer were ECTP 13 with the slab sliding off the weak layer into the pit “cash register style”. We found a small adjacent slope and walked above it and, without any effort other than approaching, remotely triggered an avalanche on this layer.

Photos:

 

Paradise Divide

CB Avalanche Center2019-20 Observations

Location: Paradise Divide Area
Date of Observation: 01/12/2020
Name: Eric Murrow and Zach Kinler
Subject: Paradise Divide
Aspect: South East, South, South West
Elevation: 10,800′-12,600′

Avalanches: No new avalanches observed

Weather: Coldest I’ve felt all year, temps in single digits. Broken to overcast skies, moderate westerly winds with stronger gusts, S-1 started around 15:00.

Snowpack: Generally 5″ of settled snow from our incremental event starting late on 1/8 in near treeline terrain. This new snow sits on a variety of old surfaces from stiff windboard to crusts in steeper open terrain on this sunny side of the compass.  Crusts at 1/8 interface on SE are thin and resting on very weak faceted snow. Winds were moving snow onto leeward and cross-loaded features with drifts up to a foot observed on certain E-SE slopes.  Fresh cornice formation on many ridgelines and cross-loaded ribs.  Cracks in drifted snow up to 10 or so feet on small drifted easterly features.  These slabs will continue to build as we add more snow and lots of wind tomorrow.

Photos

 

Anthracite Mesa-Coneys

CB Avalanche Center2019-20 Observations

Location: Crested Butte Area
Date of Observation: 01/11/2020
Subject: Anthracite Mesa-Coneys
Aspect: North East, East
Elevation: BTL

Avalanches:  Just saw 3 R1 D0.5 hard slab avalanches in the neighborhood, which looked like they occurred over a week ago.

Weather: calm, obstructed skies, and cold with air temperature less than 10 degrees F.

Snowpack: no instabilities observed on and off skin track. between 4 and 6 inches of new snow and 8 inches in a favorable area within past 48 hours. one probe at ridge top revealed a depth of 120 cm.

Small Storm Slab Axtel 1st bowl

CB Avalanche Center2019-20 Observations

Location: Kebler Pass Area
Date of Observation: 01/10/2020
Subject: Small Storm Slab Axtel 1st bowl
Aspect: North East, East
Elevation: 10500′

Avalanches:

Small storm slab broke while traversing left through small trees on a mid-lower slope in 1st bowl on Axtel. Crown about 8 inches. R1D1. Relatively small but ran into thick small trees. Rocky bed surface, probably shallower snowpack and more East facing. About 10meters wide, possibly 20meters down. Sorry no photos.

Taking a look down south

CB Avalanche Center2019-20 Observations

Location: Crested Butte Area
Date of Observation: 01/10/2020
Name: Zach Kinler and Eric Murrow
Aspect: East, South East, South, South West
Elevation: 8,800′-12,070′

Avalanches: 1 small skier triggered wind slab: HS-AS-R1-D1-I

Weather: Cold with temps in single digits to low teens. Low clouds in valley bottom gave way to sunny skies midday before orographic clouds rolled back in from the NW. Winds calm in sheltered terrain on the climb to ridgeline where moderate NW winds greeted us.

Snowpack: 1-2″ new snow overnight. Below and near treeline slopes had an HS of 50-70 cm. Open and steeper slopes held stacks of crusts with weak snow in between while low angle slopes and more easterly aspects were mostly faceted and lacking any slab. Moving above tree line, the snowpack is quite variable with many windward slopes stripped clean while gullies and inset features on South and West aspects have been cross-loaded and are holding much more snow. Recent snow and wind created very isolated and small wind slabs. On due south, supportive crusts on steeper upper elevations slopes gave way to thinner breaker crusts on lower angle terrain.

Photos: