Crown profile of skier triggered slide

CB Avalanche Center2015-16 Observations, Snow Profiles

Location: Kebler Pass Area
Date of Observation: 12/18/2015
Name: Zach Guy
Subject: Crown profile of skier triggered slide
Aspect: South West
Elevation: 11,000

Avalanches: See crown profile. Investigated the crown of a unintentional skier triggered slide that occurred earlier in the day. Skier was initially caught but not carried. SS-ASu-R1-D1-O. The avalanche broke on a layer of fist hard facets below 12/11 melt freeze crust. It was on a slightly cross loaded feature, with crown height ranging from 35cm to 20 cm. Approximately 75 feet wide and 200 vertical feet.

Weather: Light snow transport from light to moderate NW winds. Scattered to broken skies. Mild temps.

Snowpack: See profile.

image2
20151218-thortons-crown-profile

Mountain Weather 12/18/15

CB Avalanche CenterWeather

Date: 12/18/2015

High pressure is rebuilding over Colorado, bringing clear skies and rebounding temperatures through Saturday. Temps have already risen 10 degrees overnight in town, and we should see them reach the mid to upper 20’s today in the mountains and into the 30’s tomorrow under warm air advection. A series of Pacific waves will begin to impact our region beginning late Saturday night. Sunday’s system looks poorly organized, but it will signal the start of a snowy week.

Goooooood

CB Avalanche Center2015-16 Observations

Location: Kebler Pass Area
Date of Observation: 12/17/2015
Name: Than
Subject: Goooooood
Aspect: North East
Elevation: BTL

Avalanches: None aeen in our area
Weather: Cold, periods of wind with some snow transport, partly cloudy
Snowpack: New snow remained light and good in protected areas. Slabbing up out in open a little. Cut across the top of steep, small convexity with no results.

Very small wind slabs and cornice falls

CB Avalanche Center2015-16 Observations

Location: Crested Butte Area
Date of Observation: 12/17/2015
Name: Evan Ross
Subject: Very small wind slabs and cornice falls
Aspect: East, South East
Elevation: 11,700-12,300

Avalanches: Several very small natural wind slabs and cornice falls on Mount Emmons and Red Coon.
Weather: Blowing snow for several hours around mid day, then quieting down in the late afternoon. Partly cloudy sky with clouds obscuring the upper slate river valley.
Snowpack:

IMG_0877

Quick Kebler NTL/BTL Snowpack

CB Avalanche Center2015-16 Observations

Location: Kebler Pass Area
Date of Observation: 12/16/2015
Name: Evan Ross
Subject: Quick Kebler NTL/BTL Snowpack
Aspect: West
Elevation: 10,600, 11,400

11,400ft NTL, west aspect. 4F Wind hardened recent storm snow over 4F 1.5-2mm facet. No results in CT tests and minor cracking with explosives. Slope had seen previous traffic before storm.

IMG_0873

11,600ft, west aspect, BTL. About 10″ resent storm snow over large fist hard facets. No slab, no results other then sluffing in steep terrain.

IMG_0869

Mountain Weather 12/17/15

CB Avalanche CenterWeather

Date: 12/17/2015

This morning we are on the back edge of a shortwave trough that is responsible for our most recent overnight snow accumulations. By about 11am this morning our overnight totals should be in the 3-5” range for the more favored mountains west of Crested Butte. West to northwest winds looks to ramp up a little this morning as well. Snow showers look to decrease this afternoon as available moisture dissipates through the day. Friday through Saturday a shallow ridge builds bringing dryer conditions and warming high temperatures. We’ll see a return to stormy weather on Sunday.

Wind slab on Gothic

CB Avalanche Center2015-16 Observations

Location: Crested Butte Area
Date of Observation: 12/16/2015
Name: Zach Guy and Jimmy Buchanan
Subject: Wind slabs on Gothic
Aspect: South, South West
Elevation: 10,000 -12,500 feet


Avalanches: On a S/SW facing slope above treeline, we skier triggered a wind slab up to 10″ thick (4F) that ran on the melt-freeze crust interface. It was up to 250 feet wide, and ran 1,600 vertical feet. It entrained a significant amount of snow and gouged through the melt-freeze crust into facets halfway down the path. Given the terrain trap it was in, it would have buried or severely injured someone. SS-ASc-R2-D1.5-I.
We also noted several D1 to 1.5-ish looking debris piles in the Ruby Range on east aspects. Too far away to tell if these were loose or slab avalanches; presumably naturals.
Weather: Few increased to Scattered clouds. Light southwest wind with no transport. Cold temps.
Snowpack: 2″ of settle storm snow below treeline, over supportive melt-freeze crusts or dirt on S, SE aspects. Facets below the crust. The new snow was noticeably denser and more cohesive than yesterday. Above treeline, the new snow was drifted from 3″ to 10″ deep from northerly loading patterns, cracking under foot. SE, S, and SW appeared to catch most of the recent wind loading, as well as windloading events from previous storms. NW and NE aspects were bare, with plants/rocks/facets showing. E aspects showed a mix.

IMG_5366-001
IMG_5361-001

Mountain Weather 12/16/15

CB Avalanche CenterWeather

Date: 12/16/2015

The last low pressure has moved off to the east while cold air remains in place today under northwest flow. We may see a few orographic showers today, but there isn’t much moisture to see anything exiting. Mostly we’ll be dealing with cloudy skys. Wednesday night into Thursday morning, a wave in this northwest flow combined with some other lifting mechanisms and more available moisture will bring good snowfall to northern Colorado. Our area is a bit south of the better looking snowfall, but we should still see a few more inches of snow arrive with increased northwest winds. A small ridge starts building Thursday night bringing dryer weather and slowly rebounding temperatures over the following days.

Backcountry Etiquette

CB Avalanche CenterAvi Blog, Avi-Off-Season

By Zach Guy – CBAC Director
Backcountry recreation is a rapidly growing industry in the West, and equally rampant in our little valley. As the mountain regions around the U.S. becoming increasingly busy during the winter, there have also been an increase in close calls and conflicts between user groups pertaining to avalanche safety.
Several years ago, on an easily accessible peak near Teton Pass, a backcountry skier triggered a huge slab avalanche, upwards of 8 feet deep.  The slide ran thousands of feet, plowing along a drainage that is a popular access and egress point for relatively safe tree skiing.  Debris piles were monstrous, and the resulting public outcry was equally monstrous.  You can read more about the Taylor Mountain slide here. Similar issues have arisen in the Wasatch, some of the passes around Colorado, and more.  As the backcountry becomes more crowded, our need for responsible etiquette increases.  In most cases, it is to protect our fellow backcountry enthusiasts.  But in some cases, we are jeopardizing the safety of the general public who is unknowingly walking or driving their car beneath the avalanche path that you are skiing or riding.  
The slide on Taylor Mountain near Teton Pass. The skier was conducting an intentional ski cut, but the slide went much larger than expected.  Photo courtesy of TetonAT.com
Debris piles were 10-12 feet deep in the Coal Creek drainage, a launching and exit point for many backcountry skiers looking to get into relatively safe terrain.  Photo courtesy of TetonAT.com.
At the CBAC, we have been hearing feedback that our community needs a reminder about backcountry etiquette.  Even our small town has issues with over-crowding in the backcountry.  Observers have noted multiple instances where groups of skiers descended upon another group climbing the same avalanche path.  I’ve always been impressed with the attitude and etiquette of backcountry users in this community. We share observations of snowpack and avalanches, we look out for each other’s interests while on slope, and we don’t seem to hold the territorial or secretive attitudes that many ski towns around the U.S. have.  That’s one reason why I’ve chosen to live here.  Lets not lose that consideration for our community in the backcountry as more people migrate to this great backcountry destination.

So what does backcountry etiquette mean?  Simply put, be aware of your actions and their consequences in the backcountry, because they don’t solely affect you.  If you trigger an avalanche, will it affect someone down slope of you?  Communicate with people you encounter on your tours; discuss your routes and how you can avoid crossing above or below each other.  A few days ago, I found myself on top of the Anthracites on a powder day with over a dozen powder-starved locals eager to drop in.  All of the groups did a great job of communicating and divying up the terrain so that we didn’t all get bunched up on one avalanche path.  If you see a group climbing up your intended descent route, wait for them or choose another route. Its simply not worth putting them in the line of fire.  Cornice drops and ski cuts can be a great slope test, but are you absolutely sure that no one will be affected below you? Think about the size and possible extent of an avalanche that you could trigger.  Under some conditions, a slide on Red Lady Bowl or above Peanut Lake Road or on Snodgrass could run across roadways of innocent commuters.  And just as importantly, if you get injured or killed in a slide, the impacts reach far beyond just you. You have family members, friends, and community members that will be deeply impacted.

This is a natural avalanche that crossed Peanut Lake Road and the nordic track 2 winters ago.
Winter is just underway here in the Crested Butte area as our shallow and weak snowpack is starting to get buried.  We will undoubtedly see dangerous avalanche conditions developing once we see some big storms.  Lets kick winter off right. Consider your safety and the safety of others by bringing an improved sense of backcountry etiquette to the Elk Mountains.

Snodgrass Study Plot

CB Avalanche Center2015-16 Observations

Location: Crested Butte Area
Date of Observation: 12/15/2015
Name: Jimmy Buchanan
Subject: Snodgrass Study Plot
Aspect: North East
Elevation: 9,800

Avalanches:
Weather: See profile. No observed precipitation.
Snowpack: See profile. Mostly faceted snowpack with a harder layer of faceting/windpacked rounds.

profile1