Blog List

Eric Knoff
Wednesday 10/22/14

Presented at the 2014 ISSW 

In recent years, the propagation saw test (PST) gained popularity for both avalanche professionals and backcountry recreationalists. A limiting factor of the PST is the additional time required to isolate a column on the sidewall of the snowpit. Since I often have limited time to dig multiple pits during a work day, this past season I examined the effectiveness of conducting cross-slope PSTs (CPST). The CPST is simply a PST done across, rather than up, the slope. It is more efficient than the PST, particularly after conducting an extended column test (ECT).

Mark Staples
Tuesday 10/21/14

Presented at the 2014 ISSW in Banff, Canada.

For the last 24 years, the Gallatin National Forest Avalanche Center has achieved many successes in snowmobile avalanche education but many challenges remain. Building on the efforts of many others and the work outlined by the GNFAC at an ISSW twelve years ago, our snowmobile education has evolved considerably. Live recoveries, unheard of only 10 years ago, seemingly occur every winter now. 

Doug Chabot
Tuesday 4/15/14

Powder Magazine

Winter is in the rearview mirror and spring is gaining momentum but we cannot forget about avalanches. As the seasons change so do the types of avalanches. There are two ways to trigger avalanches: stress the snowpack or weaken it. Dry slab avalanches are common in winter and occur when too much weight (stress) is added to the snowpack. Under a heavy load of new snow, windblown snow or skiers, layers collapse and avalanche from this added stress. In spring the snowpack loses strength and weakens when melting water breaks down snow crystals and provides lubrication between layers. Some types of layers are more prone to this type of weakening and this season the western US has one of the worst: depth hoar.

Mark Staples
Thursday 3/20/14

 

                We have a deep slab avalanche problem throughout the advisory area. Adjacent mountain ranges likely have this problem as well. It exists because the entire winter’s snowpack rests on a layer of facets near the ground. It produced avalanches in late December and early January and again following heavy snowfall in February and early March. This weak layer of facets, formed in early December during extreme cold weather will be a concern for the rest of the season.

Doug Chabot
Wednesday 3/12/14

Published in Carve, March 2014

In a career of 15 years I have investigated a lot of avalanches. The most interesting ones are unintentionally triggered and are intriguing because they usually involve a series of decision-making failures only obvious in hindsight. This winter has been rich in such experiences. Folks have triggered many avalanches and a few have been caught and one died. Over President’s weekend three skiers were in an avalanche they triggered while skinning up Beehive Basin to the north of Big Sky. Small mistakes stacked up to create a potentially deadly situation. All too often my avalanche accident investigations involve a fatality. This accident ended with a rescue and only minor injuries. Although terrifying and sobering for those involved, I am excited about the possibility to learn and pass along the lessons to others. Avalanches involving buried skiers that don’t end tragically are rare and, to an avalanche educator, a gift.

Eric Knoff
Thursday 2/20/14

 

I'm dreaming of fresh and stable powder when the alarm cuts through the early morning silence like a buzz saw. I quickly roll over and check my phone.

It's 3:15 a.m.

There is no hitting snooze for fear that I'll fall back into the grip of sleep. I will myself out of bed to start my day.

Doug Chabot
Friday 1/31/14

Published in Carve, February 2014

I envision that should I ever be buried in an avalanche my partner will locate me quickly, put together his shovel and dig like a maniac. He will be anaerobic, spittle drooling from his mouth, sweat burning his eyes and he’ll be puffing like a locomotive. His heart rate will be in maxxed, his face red and ears ringing. I know this because I carefully chose my backcountry partners. They will give 110% of themselves to save me if I’m buried. They are mentally, emotionally and physically tough.

Eric Knoff
Wednesday 1/22/14

 

From the time snow crystals fall from the sky to time they melt in the spring, the shape and structure of each crystal never stops changing. This is known as snow metamorphism. 

Snow metamorphism determines if individual snow crystals are rounding (becoming stronger) or faceting (becoming weaker). The relationship between snow crystals ultimately dictates what kind of layer, strong or weak, is formed. The interaction between individual layers determines snowpack stability.

Doug Chabot
Wednesday 1/22/14

Cooke City has a deep slab problem: a 7+ foot thick snowpack resting on a layer of facets.  This recipe might be a preview for the rest of our forecast area since there are still months of winter left.  I tried to explain the problem with the analogy below. A proper, technical definition can be found on the Colorado Avalanche Information Center's website.

DEEP SLAB INSTABILITY: an analogy

Doug Chabot
Tuesday 1/7/14

I would love to know how many sets of tracks were wiped out in Sunday’s avalanche of the Football Field on Saddle Peak. If you carved a set consider yourself lucky. I’m going to guess that not many snowpits were dug and that the only form of stability assessment folks leaned on were that others had skied it beforehand. This was not smart. The avalanche broke during early morning avalanche control on the boundary of Bridger Bowl. An explosive was placed in-bounds, but the avalanche ripped out-of-bounds. Why?

Doug Chabot
Tuesday 1/7/14

Published in the January 2014 issue of CARVE.

The third week of December provided some valuable avalanche lessons when three people in two separate incidents triggered and were caught in avalanches near the Bridger Bowl boundary.  In both cases the parties exited the ski area into the backcountry.  The first incident involved two highly experienced skiers on Saddle Peak.  Like they have done for years, they rode the Slaschman’s lift and hiked

Mark Staples
Friday 12/13/13

Mountain snowmobiling is serious business in terms of avalanches. Modern sleds make it incredibly easy to ride deep powder in avalanche terrain. It is really fun but can also be really deadly. As always consider taking a class. Another great way to learn more is to watch a recently published series from the Canadian Avalanche Center (CAC) called "Throttle Decisions." It has 10 individual videos that were all very well done and worth watching.

Doug Chabot
Wednesday 11/27/13

Published in December issue of CARVE

I never thought I’d be concerned about my electronics while cruising around the backcountry, but I am. Carrying a cell phone, satellite phone, GPS, avalanche beacon, SPOT Messenger, and a VHF radio means my electronic signature rivals a high tension power line. I hope I don’t have to start lugging around a car battery to keep everything powered. Most people in the backcountry are not as wired as me, but a smartphone and beacon are staples for most backcountry travelers. The beacon is a literal lifeline, the most important piece of electronic safety equipment we carry. Its function is crucial to survival. As I slowly added to my electronic arsenal over the years I began to wonder, “Do all these other devices interfere with the function of my avalanche beacon?”

Doug Chabot
Thursday 11/14/13

Published in December issue of SnoWest Magazine

Snowmobilers die in avalanches every winter, killed by trauma or suffocation, an extremely unpleasant way to breathe your last breath. In the last 10 years 93 snowmobilers in western America have been killed in avalanches. This is no surprise. We love to ride steep, open, mountainous slopes in avalanche terrain. If you play in the lion’s den you may get eaten, but as riders we don’t have to go into the den when the lion is hungry.

Eric Knoff
Tuesday 11/12/13

Published in CBU November Newsletter

The day dawns cold and clear with a foot of fresh snow and the promise of incredible powder riding. At the trailhead, the surrounding landscape sparkles like a field of diamonds and the anticipation of a magical day in the mountains builds.

Sled covers are hastily removed and the machines are fired up - the smell of exhaust fills the air. Feeling confident about preparations, members of the group do a quick gear check and then hop on their machines, pinning their throttles towards the backcountry and a day of powder riding.

Mark Staples
Wednesday 11/6/13

 

YES. Portable electronics like phones, radios, GPS, cameras, etc. will interfere with an avalanche beacon (aka avalanche transceiver).  Is it a problem? The interference is significant and may prevent you from finding a buried partner. These electronic devices typically need to be turned on to cause interference. Snowmobiles with running motors and electrical circuits will also cause interference.

Eric Knoff
Friday 10/25/13

Staying on top during the Bozeman Ice Festival

By: Eric Knoff

Avalanche Forecaster - Gallatin National Forest Avalanche Center

Blue ice clings to canyon walls, creating a colorful contrast to the steep rock faces of Hyalite Canyon. Climbers inch their way up the frozen surface with axes and crampons, many having traveled from around the world to experience this world class venue.

Doug Chabot
Thursday 9/19/13

I just got back from a dawn patrol ski tour in the Bridgers! Yesterday’s snowstorm dumped heaps of snow at the higher elevations and the skiing was the better than I ever would have guessed.

Ok, I’m joking.  But admit it, you got a little excited, didn’t you?

jimurl
Friday 10/12/07

Get Avalanche Smart - Episode 3: The Great One

Some days the big lines will go, but other days they won't. It's up to you to decide, because the best days are the ones when you return home safely. Three skiers walk through the decision making process in Get Avalanche Smart - Episode 3: The Great One.