Don’t Let Bluebird Days Fool You. Here's How to Navigate the Risks of Spring Avalanches

It’s hard to resist a bluebird day in the mountains. Whether you’re a backcountry tourer, hiker, or snowmobiler, traveling through untouched terrain under clear skies is one of life’s greatest pleasures. Of course, venturing out of resorts and off established trails comes with risk. And if you’re new to the backcountry, it’s easy to assume that spring weather—and this year’s sparse snowfall across much of the western US—means avalanches are less likely, even though that’s not the case, says Emma Walker, education director at American Institute for Avalanche Research and Education (AIARE).  

“In the springtime, even in a really dismal snow year, I wouldn't say there's less risk. It's just a really different risk,” says Walker. “We’re typically dealing with different types of avalanches—what forecasters call ‘avalanche problems.’ We have different problems in a low-snow year, but that doesn't mean that they're less dangerous.” 

Mid-winter avalanches are often caused by buried 'slabs' of hard snow sitting on top of weaker, crumbly layers. They occur when a weak layer of the snowpack collapses—often after a big storm—releasing a large, heavy slab of snow that can easily bury anyone in its path. 

In the spring, these types of avalanches aren’t as common. Instead, backcountry travelers have to worry about wet avalanches (a slushy slide triggered by higher temps and rain), glide avalanches (when the entire snow cover slides down a slope), cornice falls (when overhanging snow on a ridge collapses), wind slabs (when wind moves snow to leeward slopes, forming a layer that can get released), and loose dry avalanches (non-cohesive, powdery snow that slides downhill in a fan-like pattern).

“These can still knock you off your feet and sweep you into trees or over cliffs,” says Walker. They might not be as unpredictable as slab avalanches, but they still present [a] potentially deadly risk.

The key to staying as safe as possible? Knowing how to plan a trip that manages your exposure to avalanche terrain and conditions, and getting familiar with the signs to turn back or update your route, which often differ in the spring. If you're not ready to say goodbye to skiing or snowshoeing just yet, use these tips to plan a smart adventure in the backcountry.

Start Early and Get Out Early

Snow gets softer as the day goes on and temperatures rise, which means it's less stable in the afternoon. “You should be heading back or almost back to your car by the hottest part of the day,” says Walker. Even if you plan to hike through relatively flat areas, like in a valley between mountains, you’re at risk.

“It's really rare that you wouldn't ever be crossing under or near a slope, and that’s avalanche terrain,” says Walker. Especially if you're a beginner, “it's really important to be conservative and plan to completely avoid that during the hottest part of the day.” 

Avoid Solar-Aspected Slopes in the Afternoon

“South- and west-facing aspects get the most sun exposure, so they spend the most time warming up and becoming potentially dangerous,” says Walker. Again, remember to avoid not only traveling on these slopes but also below them. Look out for terrain traps, or things that could hurt you or bury you deeper in avalanche snow, like trees, a cliff band, creek beds, and drainages.

“A place where a slope ends abruptly and flattens out is also a terrain trap, because the way the terrain sits, snow could bury you a lot deeper and make it a lot more challenging for folks to dig you out,” Walker notes. “Really being wary of those terrain traps and staying well out of runout zones [the entire area where avalanche snow and debris accumulates] is super important.” 

A compass is an easy way to determine the aspect of the mountain faces around you, but offline GPS apps can be extremely useful too—onX Backcountry, Gaia, or CalTopo are the go-tos for Walker’s team. With onX Backcountry, you can create a route based on regularly updated, guidebook-level intel and 3D maps that include overlays of crucial avalanche information, like slope aspect, slope angle (avalanches occur at roughly 30 to 50 degrees), avalanche runout zones, forecast information, and Avalanche Terrain Exposure Scale ratings. 

Related: I Reviewed the Best Backcountry Skis Money Can Buy. These Are Built to Go the Distance

Review Recent Weather Trends

The freeze-thaw cycle makes spring snow inherently volatile. If the overnight temperature where you’re planning to travel has gone above freezing multiple nights in a row, wet avalanche problems are more likely, says Walker. She recommends visiting avalanche.org to find your local avalanche forecast and see what the weather has been like for at least the last 24 hours. The forecast will include a danger rating at various elevations for the day, tell you what kinds of avalanche problems you’re looking for, and where they might exist.

Watch for Red Flags of Wet Avalanches

In spring, you’re less likely to hear avalanche indicators like the classic “whumpf,” the noise of snowpack layers collapsing. “Whumpfing is less common because of a warmer snowpack—the snow is starting to turn into more of one homogenous layer,” says Walker. That audible indicator can be a life-saving warning sign when you’re on flat ground outside of avalanche terrain. Without it, you need to keep an eye out for other signs of unstable spring snow—and avoid those areas.

Look for pinwheels and roller balls (round chunks of snow that have rolled down a slope) and runnels (meltwater channels in the snow surface); these “indicate that the snowpack is heating up and changing,” says Walker. Sinking boots and snow that’s melting or dripping off trees are also warnings for wet avalanches. Of course, the most obvious sign: Other recent avalanches.

You can learn how to better read and interpret avalanche forecasts and spot warning signs by taking a free online Avalanche Aware class. It only takes about 45 minutes and provides some fundamental information, and links to next steps, like an AIARE Level 1 Course, which can help you learn how to make on-the-ground observations and decisions. Just try to log some experience with backcountry equipment (outside of avalanche terrain) before you attend, says Walker. Test out your setup on a snow-covered golf course or field. That way, you can focus more on learning about avalanches and not how your boots and bindings work. “There’s a lot to be said for getting comfortable before you show up and are trying to learn a new, really technical skill,” says Walker. 

Don’t Get Powder Hungry

Most importantly, don’t let a late-in-the-season snowstorm push you to do something you’ll regret. “This year, I’m really encouraging people to play it safe and be conservative. The mountains will be there again next year,” says Walker. “I think there's this feeling like, ‘oh, we had such a crummy snow year. There are finally gorgeous blue skies. We finally got some snow up there.’ Or even, ‘I gotta squeeze in a couple more days on my skis before I hang them up.’ I totally get that we're all out here because we love to be outside, and we love skiing and like enjoying the snow, but there will be more and better snow years, and [chasing fresh snow] is not worth your life.” 

Related: Avalanche Survivors Used this Smartphone Feature to Get Help