IT'S JUST PLAIN DANGEROUS OUT THERE - slopes that have not avalanched are hanging in balance, just waiting for a trigger. Today, the wind might be that trigger. Many of yesterday’s avalanches broke well off ridgelines, meaning you can get out on to a slope, and have the slide break above you. Any slide you trigger on a steep slope today will be large enough to bury and kill you. This is due to weak sugary snow that is buried in the snowpack with stronger more cohesive snow on top.
If you're in a hurry you can stop reading here and move onto the wind slab definition. If your drink is still warm continue on for a brief discussion lower down.
In the book " The Art of Science of Prediction" by Philip E. Tetlock & Dan Gardner, they explain the difference between blinking and thinking. The concept is easy, we have two parts to our brains and it's a dichotomy between intuition and analysis - blink vs think. The choice isn't either/or, it is how to blend them in evolving situations. Blinking is the act of using human emotion to make decisions - you quickly decide a slope is safe based on our desire to ride epic powder, you justify things in your mind as stable because your desire is stronger. Analysis, is using all the tools in the tool box and to think, instead of blink: A good start would be to look at the bulls eye clues that tell you if a slope is unstable.
1. Recent Avalanches.
2. Cracking and Collapsing.
3. Significant snow fall within the last 48 hrs.
4. Wind.
5. Recent rapid thaw.
I think you can do the quick math on the list above. The book then tells a quick story about a fire chief called to a routine kitchen fire. "The commander order his men to hose down the fire while standing in the living room. The fire subsided at first but roared back. The commander was baffled. He also noticed the living room was surprisingly hot given the size of the kitchen fire. And why was it so quiet? A fire capable of generating that much heat should make more noise. A vague feeling of unease came over the commander and he ordered everyone out of the house. Just as the firefighters reached the street, the floor in the living room collapsed - because the real source of the fire was in the basement, not the kitchen." There is nothing mystical about an accurate intuition like the fire commander's. It's pattern recognition - like cueing in on the 5 clues to avalanches. If you're seeing avalanches, hearing about avalanches - guess what? YOU CAN TRIGGER AVALANCHES.
Ian McCammon did roughly the same thing when he created the system called ALPTRUTH. He wondered why skilled people were dying in the backcountry. He looked at hundreds of avalanche accidents and came up with a list of seven factors that were present in many, if not all of the backcountry accidents he studied.
The list is below:
1. Avalanches in the past 48 hrs?
2. Loading by snow, wind or rain in the past 48 hrs?
3. Path - are you in an avalanche path?
4. Terrain Trap - Gullies, trees, cliffs or other features that increase the severity of being caught?
5. Rating - Considerable or higher avalanche hazard on the current advisory?
6. Unstable Snow - Collapsing, cracking, hollow sounding snow or other clear evidence of instability?
7. Thaw - Recent warming of the snow surface due to sun, rain or warm air?
The process is simple: for every factor present you give it a score of 1. Ian McCammon found that in almost all of the avalanche accidents he looked at had 3 or more points assigned. To be very clear, if you simply didn't go anytime that 3 or more points are present, you would avoid almost all avalanche accidents. How many points are already checked for today? I count 4.
