Zahan demonstrates a belay at last year's IPRW. Ryan Dunfee photo.
Yesterday marked the second day of IPRW and TGR's Safety Week. Exum mountain guide Zahan Billimoria gave a presentation to TGR athletes about a system to objectively decide whether it is safe to ski line in the backcountry. The system was developed by Ian McCannon and is based on similarities in avalanches. McCannon identified seven factors that contribute to slides.
Based on his research, in 97% of the avalanche incidents studied, three or more of the seven factors were present. He developed the acronym ALPTRUTH to help remember the factors. According to Zahan, if three or more factors are present, that should trigger a red flag in your mind, and you should consider whether your plans still make sense.
Disclaimer: This article does not attempt to replace any formal avalanche training. Anyone looking to travel in the backcountry safely should attend a formal class. We hope this serves as a reminder and tool to make safe decisions in the backcountry.
Aftermath of the Breakneck avalanche that broke when a snowboarder rode into the face after a huge snowcycle in Jackson Hole last March. Bridger-Teton Avalanche Center photo.
A is for Avalanches: Check for recent avalanche activity and take note if there has been a slide in the past 48 hours. Look for the debris on the side of the road on places like Teton Pass, or when approaching the area. Check to see if local avalanche centers recently posted activity on event maps.
L is for Loading: Has it snowed or rained in the past 48 hours? When it did snow, was it roughly an inch an hour for six or more hours? If so, then take caution.
A Jeremy Jones photo of a perfect "clean" line: an obstacle-free straight fall line descending into a flat run-out. Read why Jeremy rides clean lines on the Jones Snowboards blog.
P is for (Avalanche) Paths: Is there a defined avalanche path in the area you are going to ski? It should be fairly obvious, even to a novice, to notice areas that would cause snow to naturally funnel. Be on the lookout for defined avalanche start zone and a pitch around 38 degrees.
T is for Terrain (Traps): Terrain traps are features that exacerbate the consequences if you get caught in an avalanche. There are three major types of features. The first is something you can fall off of, like a cliff. The second is something you can smash into, like trees. The third is a confined area where the snow can compact quickly, like a couloir or gully, where even small avalanches can easily bury a victim.
If you are skiing are there hazards like trees if a slide occurs.
R is for (Avalanche Hazard) Rating: What is the avalanche danger for the day? Check in with your local avalanche center and take caution if considerable, high, or extreme avalanche hazard is listed, but realize that most avalanches happen during days of moderate hazard–when the danger isn't so obvious as to keep people away, varies across terrain, and fools people into thinking it's "safe" out.
U is for Unstable (Snow): Can you hear collapsing or a "whumping" sound while traveling through the backcountry? When you dig a snow assessment pit, is there a heavy layer on top of a weak one? Do you observe cracks in the snow? If so, then unstable snow is present. This is particularly important if it exists in the top three feet of the snowpack–where skiers and snowboarders are able to trigger avalanches most readily.
T is for Thawing: If you observe 12-15 degrees of warming in a period of twelve hours or less, then check yes in this category. It is important to note that this only should only be checked if it is the first day of warming, not a day in a long warming period.