Mountain Weather 11/28/2016

CB Avalanche CenterWeather

Date: 11/28/2016

There will be a break in the weather this morning as last night’s larger scale lift breaks down. We’ll still be sitting under northwest flow so clouds and some very light snow showers may continue in the mountains west of Crested Butte. The next wave of energy looks to arrive around mid-day. Snow showers should develop over the entire forecast area, but this wave will again favor the western and northern boundaries of our forecast area, thanks to northwest flow and orographics. Today’s total snow accumulations across the forecast area don’t look to impressive, especially compared to yesterday. Though I’ll put some higher numbers in the forecasted snow totals as orographics could really bump those snow numbers up in the favored Kebler Pass and Paradise Divide zones.
Mostly cloudy skys will persist on Tuesday with only a few lingering snow showers. The Crested Butte Area and further east will likely be mostly dry, while orographic will keep some snow showers going in those orographically favored area. Wednesday through Friday will see a continued drying weather pattern.

Today

High Temperature: 18
Wind Speed: 10-20
Wind Direction: W
Sky Cover: Overcast
Snow: 5-8W/2-4E

Tonight

Low Temperature: 5
Wind Speed: 5-15
Wind Direction: NW
Sky Cover: Overcast
Snow: 5-8W/0-2E

Tomorrow

High Temperature: 12
Wind Speed: 5-15
Wind Direction: NW
Sky Cover: Overcast
Snow: 0-3

Near Treeline Obs

CB Avalanche Center2016-17 Observations

Location: Paradise Divide Area
Date of Observation: 11/27/2016
Name: Evan Ross
Subject: Near Treeline Obs
Aspect: North East, East, South East
Elevation: 11,000

Avalanches: Remote triggered one persistent slab from a couple hundred feet away. Shooting cracks spanning multiple aspects of a gully that pulled out a small avalanche on a steeper 40ish degree slope.
Weather: Snowfall rates in the S1-S5 range throughout the day. Gusty down valley winds blowing, swirling and drifting new snow about. Never made it to ridegline.
Snowpack: HS about 50-60 cm on East and Southeast Aspects. Generally fist hard snow consisting of the Thanksgiving and the current storm without an obvious or reactive interface between them. These storms where resting on a varying thickness and generally soft crust just above the ground. No signs of instability on the slopes traveled. This would have likely been a different story on slopes with additional wind loading.

HS about 65-70cm on Northeast aspects. The Thanksgiving storm had more slab structure 4f- and was sitting over about 10-15cm of 2mm faceted particles. Shooting cracks and collapses while traveling near these slopes. Persistent slab avalanches felt likely to trigger on convex terrain features or slopes over 35 degrees. Small NSF also looked to be present at the interface of the Thanksgiving and todays storm, though didn’t get much time to look into it more.

Below treeline slopes generally lacked enough snow for an avalanche problem, except for potentially a very isolated and wind effected terrain feature.

65cm crown of a small remotely triggered persistent slab.

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Flank profile dug into some shooting cracks.

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Shooting cracks ran down the middle (northeastern) and right (norther) slopes of this gully.

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Gothic 7 a.m. report

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 11/27/2016
Name: billy bar
Subject: Gothic 7 a.m. report
Aspect:
Elevation:

Avalanches:
Weather: Strong wind from 5:30 to 6:15 but now light again. Snow at sweep time 3″ new and 0.23″ of water. Temp. holding at 24F and clouds have lifted some. Snow paused the past half hour but just starting up again very light. Snow depth at winters deepest of 9″. billy
Snowpack:

Mountain Weather 11/27/2016

CB Avalanche CenterWeather

Date: 11/27/2016

Snow starting falling as forecasted early this morning as a trough of low pressure pulls moisture into the area on southwest flow. The San Juan Mountains have some nice new snow numbers this morning while we’ll be seeing our share a new snow as snowfall rates look to pick up around 9:30am this morning. The most recent weather models show the low pressure trough sagging a bit further south and east than previous forecast discussions, taking some of the best moisture and weather dynamics with it. That takes some of the excitement out of my sails and adds in a little bit of uncertainty in estimated total snowfall numbers as models are still forecasting some nice total snow numbers in our area for Sunday and Monday. So we’ll have to wait in see how it all shakes out. After this morning pulse of snowfall we’ll likely see a decrease in snowfall rates this afternoon, before another pulse arrives after dark this evening and winds becoming more westerly to northwesterly. A third pulse of snowfall is forecasted to arrive mid-day Monday favoring Central and Northern Colorado as winds continue from the west to northwest. Wednesday through Friday will bring dryer air as we sit in cool northwest flow between low pressures to our East and West. The next system moving across the US towards the end of the week looks to mostly miss Colorado and dive even further south.

Today

High Temperature: 24
Wind Speed: 15-25 G40
Wind Direction: SW, W
Sky Cover: Overcast
Snow: 6-8

Tonight

Low Temperature: 15
Wind Speed: 10-20
Wind Direction: W, NW
Sky Cover: Overcast
Snow: 3-5

Tomorrow

High Temperature: 18
Wind Speed: 10-20
Wind Direction: W, NW
Sky Cover: Overcast
Snow: 2-4

Anthracite area

CB Avalanche Center2016-17 Observations

Location: Kebler Pass Area
Date of Observation: 11/26/2016
Name: Alex Banas
Subject: Anthracite area
Aspect: North, North East
Elevation: 10-11,200′
Weather: Clear skies, calm wind from the west. Temps in the mid 20’s.
Snowpack: Overall weak and shallow snowpack observed throughout Anthracite Zone. The persistent slab problem was not observed below treeline. At treeline the persistent slab problem produced numerous collapses and visible cracking throughout the test slope area. 11,200′ NE 33* Surface grains: .5-1.5mm Facets/DF HS: 53cm CT 13 SC ECTP 9 SC Both failed 37cm down in 2-6mm depth hoar.

HS showed a shallow snowpack from 15-53cm. Surface hoar was observed on shady slopes below treeline while none was observed near treeline in open wind affected areas.

10,325′ North East
HS: 20cm Surface hoar observed wide spread on shady slopes.

10,900′ N 30* slope
HS: 35cm. Depth hoar capped by a 1cm melt freeze crust. Facets to the surface.

11,200′ NE 33* Persistent slab structure found
HS: 53cm CT 13 SC ECTP 9 SC Both failed 37cm down in large facets

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FullSizeRender

Mountain Weather

CB Avalanche CenterWeather

Date: 11/26/2016

One more pleasant day in the mountains before our pattern shifts towards active and wintery weather. Sunny skies and mild temps will give way to thickening clouds this evening, signaling the onshore arrival of a deep trough tapping into Pacific moisture and supported by the jet stream. The trough elongates over the Western U.S. and slowly migrates eastward into next week. This brings a series of strong snowfall pulses through Wednesday to the Elk Mountains that may require a yardstick to measure when all is said and done. The action kicks off Sunday morning as strong southwest flow spreads snowfall across the region accompanied by strong winds. Snowfall gets an orographic boost through the day as flow shifts towards the west. An embedded shortwave brings increased snowfall again on Monday.

Today

High Temperature: 32
Wind Speed: 2-12
Wind Direction: SW
Sky Cover: Clear
Snow: 0

Tonight

Low Temperature: 18
Wind Speed: 10-20
Wind Direction: S
Sky Cover: Increasing clouds
Snow: 0-2″

Tomorrow

High Temperature: 22
Wind Speed: 15-25, G35
Wind Direction: SW, W
Sky Cover: Overcast
Snow: 5-9″

South aspect

CB Avalanche Center2016-17 Observations

Location: Paradise Divide Area
Date of Observation: 11/24/2016
Name: EM
Subject: South aspect
Aspect: South East, South, South West
Elevation: 10000 – 12500

Avalanches: several small windslabs were visible throughout the range. All were confined to Wednesday nights snowfall.
Weather: Clear skies with cold valley temps and strong winds transporting snow off many alpine features and peaks in AM. Around noon winds had eased off and snow transport mostly stopped.
Snowpack: Many low elevation areas closer to 10k were composed of snowfall from just this past week. With snow from earlier storms melting off. Closer to treeline there was generally a suncrust at the ground covered by the previous weeks snowfall. Some slopes above 115000 had cohesive slab developed above this crust from past weeks snow and wind. Several locations showed this interface to be bonded relatively well.
At one location, 12500, south facing, 29*, start zone just below ridge top, we found that the wind blown snow from Wednesday night had bonded poorly to the snowfall from earlier in the week. Easy to moderate, Q2 results 18 cm down on surface facets (seemed slighly to thick of layer to be surface hoar). This location had clearly been stiffened by winds that came with the previous nights snowfall. We actively avoided this area of slabby snow. More protected features down slope didnt have this surface slab structure.

Purple Ridge

CB Avalanche Center2016-17 Observations

Location: Paradise Divide Area
Date of Observation: 11/24/2016
Name: Chris Miller
Subject: Purple Ridge
Aspect:
Elevation:

Avalanches: See photos
Weather:
Snowpack: Collapse and shooting cracks on N/NE purple ridge

Small windslab pockets on Richmond
Small windslab on Purple Ridge
Shooting cracks
North Cirque on Augusta

Human Factors and Decision Making

CB Avalanche CenterAvi Blog, Avi-Off-Season

Human Factors and Decision Making

By Zach Guy, CBAC Director

This year’s theme to CBAC’s Avalanche Awareness Night on December 2nd, 2016 is “Human Factors and Decision Making”. Almost all avalanche accidents are triggered by the victim or a member of their group. We are the ones who expose ourselves to avalanche risks, and often it is our own decision making that puts us into trouble.

Although humans have been pondering our methods of thinking and rationalizing for centuries, Ian McCammon has been instrumental in research in the avalanche industry. I was fortunate enough to have Ian as a course instructor and mentor for my AVPRO class about 7 years ago, and caught up with him to ask a few questions about human factors and decision making.

Ian McCammon. Photo courtesy of POWDER magazine.

Zach Guy: Ian, you have a PhD in mechanical engineering, and a Master’s in Material Science. In the avalanche world, you are well known for your research on human decision making. What inspired your shift in focus from physics towards psychology?

Ian McCammon: My own journey started years ago when a friend of mine died in an avalanche. Using tools from my engineering background, I searched for statistical trends in hundreds of past accidents and found that the circumstances of my friend’s death followed a pattern that repeated itself again and again: risk perception for certain groups was distorted under certain conditions.

Zach: In 2002, you published a paper on heuristic traps and how these human factors affect our decision making and influence avalanche accidents. The acronym “FACETS” (Familiarity, Acceptance, Consistency, Experts, Tracks/Scarcity, and Social Facilitation) has been adopted by essentially every avalanche course around the country to introduce these human factors. My talk at Avalanche Awareness Night will dive into some of these factors and a close call that I had back in 2009. In your research or simply from personal experience since then, are there any other human factors that you think backcountry travelers should be aware of?

Ian: Fatigue is an important physiologic factor that influences our decision making. When you are tired, dehydrated, hungry, cold or just sucking air from a long ascent, it’s hard to judge hazards objectively. And just like the FACETS cognitive traps, fatigue is dangerous because people consistently underestimate how profoundly it can impair their judgement.

Zach: You developed some systematic tools to help backcountry travelers overcome our human biases, such as ALPTRUTH and Lemons. Do you have any other personal tips or strategies that you use in your ski tours for overcoming the inherent biases in the way our brains process information and make decisions?

Ian: ALPTRUTh was designed to do two things. First, it stops you at the cusp of a decision – it breaks the momentum that sometimes carries people into trouble. Second, it helps you see how your group’s decision will be viewed should an accident take place – a process called a pre-mortem. There are other ways to do this, and my hope is that new and better tools will emerge from research into this important area.
Another strategy in addition to APLTRUTh is to choose your partners wisely. Choose people with the wisdom to stop the group’s momentum at the right times and reconsider evidence and the opinions of the group. If they can do that, it’s going to be less frustrating and more effective to manage risk as a group.

Zach: Social media has exploded since your original research 15 years ago. We have a presenter who will be touching on this subject at Avalanche Awareness Night. With Facebook, Instagram, Youtube, etc., the entire internet is watching what we do in the backcountry. What is your take on the impact of social media on our decision making, and do you suggest or have any strategies for handling its potential influences?

Ian: This is a fascinating and worthy topic for research. I am glad you have a presenter exploring this subject. Some folks are choosing to literally create their social identities in near-real time as their decisions and outcomes are posted and amplified across an audience of friends and potential critics. An important question for each of us is how much are we willing to allow that unseen audience to shape our critical decisions.

Zach: Any parting words for our Colorado audience that recreates in the deadliest snowpack in the country?

Ian: To paraphrase Baltasar Gracian: Know your major weakness. If you do not understand it, it will rule you like a tyrant.

Zach: Thank you Ian for sharing your wisdom, and for your contributions to the avalanche industry.

 Join us at CBAC’s Avalanche Awareness Night for more great presentations on human factors and decision making.

Gothic Obs

CB Avalanche Center2016-17 Observations

Location: Crested Butte Area
Date of Observation: 11/24/2016
Name: billy barr
Subject: Gothic Obs
Aspect:
Elevation:
Snowpack: Turning cloudy after dark with strong wind and light snow starting around 9:30 p.m. and going all night, though seemingly letting up near sunrise. Only 2″ new snow and 0.13″ water but a lot of snow transport with the wind so drifting. Snow pack at 6″ deep, tied for the deepest so far this winter. Currently overcast with light to moderate west wind and very light snow. billy