Ski patrol explains avalanche control at Squaw Valley
The death of a 64-year-old Aptos man at Mount Rose Ski Resort this month punctuates the fact that the Sierra snow season, for the second year in a row, is starting out with dangerous avalanche conditions.
After four years of drought, last season featured similar conditions, with several avalanches reported by U.S. Forest Service officials and the death of a 23-year-old ski instructor who apparently wandered off course at Sugar Bowl Resort.
“This year has been a little more dramatic,” said Steve Reynaud, a forecaster at the Sierra Avalanche Center, noting that four “atmospheric river” storms have dumped heavy snow in the higher elevations this season.
As of Friday afternoon, the center had placed the Lake Tahoe region under a warning of “considerable” avalanche risk. The level 3 warning, in a system with 5 as the most dangerous, was in effect until Saturday morning.
The forecasters at the center make field observations on backcountry skis, and use that information with weather data to come up with regular avalanche forecasts.
Friday’s forecast was based on two problems in the snowpack. Big, continuous slabs of snow have been formed by high wind, and they can break up and turn into an avalanche, sending a torrent of heavy snow down a slope. At the bottom of the snow layers is a “persistent and weak layer” 3 to 6 feet below the surface.
“Large destructive and unsurvivable avalanches are possible today,” the forecast stated Friday.
Avalanches can prove fatal, particularly if the buried victim does not have a special beacon that can alert rescuers to an exact location.
Thursday and Friday’s “atmospheric river” brought a lot of precipitation to the mountains, but a lot of it was rain, which generally is less a problem of avalanches than snow. However, Mount Rose – which at just under 10,000 feet is the highest resort in the Tahoe Basin – reported that it had received 12 to 21 inches of new snow.
That pattern has been true all season, with Mount Rose getting snow when other areas received rain. Snow monitoring sites maintained by the National Resources Conservation Service showed that the “snow water equivalent” – the amount of water in snow – was at 156 percent of average at Mount Rose on Friday. Other locations in the Tahoe Basin, including Truckee and Heavenly Valley, were below average. Statewide, the snow water equivalent was at 73 percent of average Friday, with most of the snow in the Sierra, according to the state Department of Water Resources.
Mount Rose had the nation’s first avalanche fatality this season, according to the Colorado Avalanche Information Center. The day after the Mount Rose fatality, a backcountry skier was fatally buried by an avalanche in Montana.
In the Mount Rose fatality on Dec. 10, Thomas Vincent Barker and another skier went into a closed and ungroomed section of the resort called the Chutes, said Mike Pierce, marketing director at Mount Rose. That section remains closed because it has not had enough snow in the lower elevations.
According to a preliminary report by the Sierra Avalanche Center, the skiers dropped into a steep, wind-swept area, and Barker triggered an avalanche that swept him 600 to 1,000 feet down slope and buried him under 5 feet of snow.
The other skier immediately called 911, but even with avalanche teams from Mount Rose and other resorts and search-and-rescue teams from Placer and Washoe counties, Barker’s body was not located until the middle of the following day, the preliminary report states.
Last season’s one Sierra avalanche death occurred under similar circumstances. Carson May, an instructor at Sugar Bowl, was apparently skiing off trail when he was buried in snow in January. Stormy conditions forced rescue teams to abandon the initial search for May, whose body was not found for more than six weeks.
Avalanches on open ski runs are relatively rare because the resorts monitor and control the snow. Sierra resorts have varying degrees of avalanche risks, depending on how much snow they get and the steepness of the terrain. At Mount Rose, the ski patrol regularly checks the snow for avalanche risk, and uses explosives to blow up dangerous formations, Pierce said.
Greater risks exist in the backcountry, where people travel on skis and snowshoes. A popular backcountry activity in the Tahoe area is to snowshoe or ski to one of the Sierra Club’s four ski huts.
Peter Lahmkuhl, general manager of the club’s Clair Tappan Lodge, said the huts are booked nearly every weekend in the winter. The Sierra Club instructs people to check the Sierra Avalanche Center reports when they head out to the huts and to bring appropriate equipment to find and recover people buried in an avalanche, he said.
Most people are aware of the risks, he said, and those who aren’t are advised to take less risky trips.
Deadly avalanches in California and Nevada
Twenty-six people have died in avalanches in California and Nevada since 2000, most of them occurring in backcountry or off-limits areas around the Lake Tahoe ski region.
Between Squaw and Alpine
Backside of Mount Judah
East of Mount Rose
Charity Valley in Alpine County
Castle Peak, north of Donner
Lee Canyon, Las Vegas
North Bowl of Mt. Anderson
Mt. Tom, Inyo County
Twin Lakes area; San Bernardino
backcountry, Mountain High
Sequoia National Park
Poulsen’s Gully, Squaw Valley
near Maggie’s Peak, Lake Tahoe
Split Mountain near Bishop
Ward Canyon, Alpine Meadows
Donner Ski Ranch
Mount Mallory, Inyo County
Backside of Mount Judah
Closed area, Mt. Rose Chutes
Sources: U.S. Avalanche Accidents Reports, American Avalanche Association and Colorado Avalanche Information Center