Snow problem 

Avalanche dangers persist in Montana’s mountains

As part of their twice-weekly monitoring trips, Steve Karkanen and Dudley Improta of the West Central Montana Avalanche Center (WCMAC) toured upper Grant Creek Basin above Montana Snowbowl on Jan. 4. Fresh snow obliterated all signs of Karkanan’s ski track from four days prior, and a major slide had ripped out from near one of their monitoring pits. Still, the two veterans found enough improvement in the snowpack to drop the current avalanche rating from “High” to “Considerable.”

During a particularly dangerous winter, this was a rare and welcome improvement. Avalanche deaths in the West are soaring this season, with casualties reported from Whistler to Jackson Hole, at resorts and in the backcountry. While slides haven’t claimed a life in Montana, the local snowpack is similar—and similarly dangerous—to conditions found elsewhere, says Karkanen.

“The problem this year is that we got rain up to 10,000 feet in early December, followed by super cold weather that lasted for 10 days,” he says.

That cold weather caused the surface to grow crystals, a “hoar” that, unlike intact snowflakes, regularly fails to bond with adjacent snow layers. In December, Karkanen found unstable crystals occupying up to 30 centimeters of the snowpack, creating extremely dangerous conditions and prompting WCMAC to issue its first two avalanche warnings of the season.

This dangerous layer can persist long after storms literally bury it with tons of snow, leaving it insulated from the temperature and weather fluctuations that can help it stabilize. Around Missoula, four or more feet of heavy snow have piled upon the crust, and the suspect layer remains precariously loaded with massive amounts of snow. In order to slide, Karkanen says only one component is missing: a trigger, such as a skier, snowmobile or, as in the current conditions, a warm day.

“Slides are running on their own accord,” he says. “As soon as the weather warmed up I got calls from people up and down the Bitterroot saying they’d been seeing huge crowns from the valley.”

Crowns are the clean break at the top of an avalanche, and their height indicates the depth of the snow released. A crown visible from the valley floor likely indicates a catastrophic event. But while skiers in Montana have reported seeing slides, none have been trapped.

More than 30 skiers elsewhere in the region haven’t been as fortunate. Two former ski patrollers were killed in Colorado, one at Aspen, the other near Crested Butte. Another skier was killed at Alta Ski Area in Utah, and another at Jackson Hole Mountain Resort in Wyoming. Two days later, the Jackson Hole Ski Patrol intentionally released an early morning slide that blasted more than eight feet of snow into a patrol shack, restaurant and tram dock, trapping employees and other ski patrollers; the crew cut through a wall to escape. Just north of Whitefish in Canada, 11 snowmobilers were caught in a series of horrific slides that left eight of them dead. And on Jan. 2, an ice climber near Cody, Wyo., was swept off the frozen falls to his death after a slide released above him.

“It seems that this is a pretty widespread condition all over the West,” says Karkanen. “At one point last week every avalanche forecasting site in the West was issuing warnings for avalanche danger. I don’t want to say that we have exactly the same conditions as Colorado, but it’s very similar.”

If anybody knows, it’s Karkanen, WCMAC’s director. The experienced ski patroller and Improta, UM’s assistant director of Campus Recreation, focus on snow conditions in the Rattlesnake, Bitterroot, Mission and Southern Swan mountains. The center—along with the state’s two other avalanche forecasting centers, the Glacier Country Avalanche Center in Kalispell and the Gallatin National Forest Avalanche Center in Bozeman—encourages backcountry users to submit snow reports from other locations on its website (www.missoulaavalanche.org), all in an effort to provide as much information as possible for those heading into Montana’s backcountry.

In December, Karkanen’s first report of the season correctly identified the source of today’s concerns. He cited “pockets of buried surface hoar crystals” and a concern for buried “rain crusts.” “While these features are not currently much of a problem, they will need to be treated with suspicion once it starts snowing heavily,” reads the archived report.

While WCMAC refers to this crust as the “early December ice layer,” others in the backcountry community refer to it as the “St. Mary’s Layer.” It’s a reference to the icy sheen that covered the popular Bitterroot summit when hikers Steven “Max” Haldeman, 29, and Lisa R. Jones, 42, are believed to have lost their footing and slid to their deaths last month.

As the snowpack continues to settle, the buried layer will likely become less dangerous. But as Karkanen and Improta finished their Jan. 4 monitoring trip, the pair pointed to location after location of the previous slides, rescues and deaths they’ve witnessed in their decades of assessing snow in the basin. Many skiers have misjudged their skill level and/or avalanche danger here and have paid with injuries and, sometimes, lives. And while the center is offering multiple courses in avalanche safety this month, Improta declares that nothing beats boots-on-the-snow experience.

“You can take a lot of classes and still not be able to put it together in an intuitive way until you spend some time on the snow,” he says. “That’s how you really get educated.”
  • Email
  • Print

More by Chad Harder

© 2015 Missoula News/Independent Publishing | Powered by Foundation