Wednesday, April 20, 2011

Slides show avalanche danger is not over

Snowpack still unstable in some areas


By KATHERINE WUTZ
Express Staff Writer

Snow season may be over for the valley, but two avalanche incidents over the weekend show the danger is far from past.

The Sawtooth National Forest Avalanche Center reported earlier this week that the remaining snowpack is neither stable nor predictable.

"It's the time of year that people like to get into steeper terrain because stability is typically more predictable," said Blase Reardon, a forecaster for the center. "Right now, it's not."

Normally, warmer temperatures help to set up a more stable, solid snowpack during April and May. This year, however, that's not the case.

Two parties of skiers were caught off guard over the weekend when slides began unexpectedly. Reardon said a party of four skiers had a close call in the Comma Couloir on Cobb Peak in the Pioneers on Saturday, when a buried wind slab gave way. The slab slid down the couloir, carrying three of them 1,200 feet.

Reardon said the skiers were "pretty badly beaten up" and severely damaged their gear, but are expected to recover.

Two more skiers managed to escape being caught in a slide on Copper Mountain, near Banner Summit west of Stanley, the same day when they triggered another buried wind slab. Reardon said the skiers were following proper protocol—traveling one at a time over the area they suspected might be unstable—and were able to avoid injury.

"They were very aware of the risks and of the terrain change," Reardon said. "They saw [stability] was going to be a problem, and so they're fine."

Chris Lundy, executive director of the Sawtooth Avalanche Center, turned back while skiing in the Sawtooths over the weekend due to conditions. As in most of the region, Reardon said a combination of new snow and unpredictable, varied winds caused the instability in the Sawtooths, conditions that persist across the valley.

Over 2 and a half feet of new snow has fallen in higher elevations since the beginning of April, Reardon said. The area where Lundy was skiing had received 15 inches of snow over night, and winds averaging from 15 to 25 miles per hour had created some unusual wind slabs.

"[The weather] is quickly forming and burying wind slabs," Reardon said.

He said the slabs can give way unexpectedly, as in the cases over the weekend.

The weather causing the tricky conditions may be set to come to an end this week.

According to the National Weather Service, the area around Galena Summit is likely to receive only a few inches of snow over the next week, and with temperatures reaching the high 30s, the Weather Service seems more concerned about snowmelt, and has issued a flood warning for the area.

Katherine Wutz: kwutz@mtexpress.com




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