The Danger Scale Isn't Linear: Why 'Considerable' Avalanche Risk Can Kill You

You've heard it a hundred times: "Check the avalanche forecast before you head out." But here's the misconception that gets people killed: that the avalanche danger scale is a simple 1-to-5 dial, where each step up is just a bit worse than the last. That's wrong — dangerously wrong. The scale is exponential. A jump from Moderate to Considerable doesn't mean slightly more caution; it means a fundamentally different game. And the most deadly rating of all isn't High or Extreme — it's Considerable. Here's why, and what you must do about it.

Imagine You're a Ski Tourer in Colorado

It's a bluebird Saturday in January. You and your partner are planning a tour in the front range. You check the forecast from the Colorado Avalanche Information Center: danger rating is Considerable at and above treeline. You've skied in Considerable conditions before, and it was fine. You figure you'll stick to slopes under 30 degrees, avoid obvious terrain traps, and you'll be okay.

Stop right there. That plan is exactly how avalanche fatalities happen. At Considerable danger, natural avalanches are possible, and human-triggered avalanches are likely (avalanche.org). Not just possible — likely. And here's the kicker: the danger scale isn't linear; it's exponential (avalanche.org). The jump from Moderate to Considerable is huge — far bigger than the jump from Low to Moderate. Most avalanche accidents happen at Considerable danger, because people underestimate the risk and go into terrain they shouldn't. But the forecast isn't just a number; it's a call to rethink your route.

Parks Canada is blunt: at High or Extreme danger, the general public should avoid avalanche terrain entirely, or stay within resort boundaries (Parks Canada). But at Considerable, the advice is more nuanced — and that nuance is what gets people. You can't just avoid the obvious avalanche paths; you have to avoid all avalanche terrain, because even a small slope can slide and bury you.

What 'Considerable' Actually Means

Let's break down what the scale really tells you. The North American Public Avalanche Danger Scale has five levels: Low, Moderate, Considerable, High, and Extreme. Each level comes with a likelihood of avalanches and recommended travel advice. At Considerable, natural avalanches are possible and human-triggered avalanches are likely (avalanche.org). That means the snowpack is primed to release when you ski over it — not if you're unlucky, but if you're an average skier tempting fate on a 35-degree slope.

And remember, the danger rating is given for three elevation bands (avalanche.org). The danger might be Considerable above treeline but Moderate below. So you think you're safe by skiing lower? Maybe — but the scale is exponential, so even a "Moderate" rating in the right (wrong) conditions can produce a deadly slide. The key is to not just look at the number, but to understand what that number means for the specific terrain you're in.

Here's my hard recommendation: if the forecast says Considerable in the elevation band you plan to ski, stay out of avalanche terrain entirely — unless you have formal avalanche training, you're carrying a beacon, shovel, and probe, and you've carefully assessed the slope's angle and aspect. I don't care if you've skied it 50 times before. The snowpack changes every day, and Considerable is the new High.

The Numbers Behind the Risk

Still skeptical? Look at the fatality stats. Since 1995, U.S. avalanche fatalities have hovered around 25 to 30 per year, despite an estimated 8-fold increase in backcountry use (avalanche.org). That's a testament to better education and forecasting, but it also means the people dying are not just clueless novices — they're often experienced backcountry skiers who made a poor decision on a Considerable day. Backcountry use has skyrocketed, yet fatalities haven't dropped; if the rate had stayed constant, we'd see over 200 deaths a winter (avalanche.org). The fact that it's "only" 30 is because of safety measures, not because the mountains are safe.

And here's a sobering thought: since 1995, the number of avalanche advisories accessed has exploded — 12-fold at Utah, 17-fold at Colorado, 36-fold at Gallatin (avalanche.org). We're checking the forecast more than ever, yet we're not reducing deaths. Why? Because we check the forecast, see "Considerable," and then go anyway, thinking we can outsmart the snow.

Don't be that skier. If you're heading into the backcountry, take an avalanche course, practice with your gear, and make conservative decisions. And if you're at a resort, you're not immune — but that's a different article.

What to Do When the Danger Is Considerable

So what's a skier to do? First, if you're not trained, don't go into avalanche terrain at Considerable danger. Period. Take an AIARE Level 1 course, learn to read the forecast, and get experience with a mentor. If you are trained, then be ruthless about terrain selection. Stick to slopes under 30 degrees, avoid terrain traps like gullies and cliffs, and always expose only one person at a time to a slope.

Here's a quick tip: when the danger is Considerable, the safest terrain is often the least spectacular. A low-angle glade or a ridge walk can be just as fun as a steep chute — and you'll live to ski it again.

Warning: Do not rely on your beacon to save you. Avalanche rescue is a race against time, and most burial victims die from asphyxiation. The only way to survive is to not get buried.

In the end, the most important thing to remember is this: the avalanche danger scale is not a suggestion; it's a guide to whether you will die today if you make a mistake. When it says Considerable, treat it as High. When it says High, stay out of the backcountry. And when it says Extreme, stay home. Because the snow doesn't care how many days you've skied.

Sources

• Avalanche danger scale - https://avalanche.org
• Parks Canada avalanche danger scale - https://www.parks.canada.ca/pn-np/mtn/securiteenmontagne-mountainsafety/avalanche/echellerisque-dangerscale
• Avalanche fatality trends (WEM/USDA) - http://avalanche.org/wp-content/uploads/2018/07/17_WEM_Birkeland_etal_AvFatalities.pdf