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he winter season of 2007–2008 had the most avalanche fatalities seen in Washington in modern times, discounting the icefall accident on Mount Rainier in June 1981. What happened? First let’s look at this winter’s weather patterns and snowpack growth. Winter Weather Summary
The next storm cycle extended from mid December to mid January. Hurricane Ridge in the Olympics and locations near and west of the Cascade crest accumulated 17 to 24 feet of snow during this one-month period. Many sites had several days, sometimes consecutive days, of a foot or more of snowfall. Snowfall was especially heavy at Mount Hood. Three more avalanche accidents, on December 18, New Years Day, and January 4, claimed the lives of four more people. Another storm cycle extended from the last few days of January through the first half of February. Sites near and west of the Cascade crest picked up 10-15 feet of snowfall during this two week period. All three major Cascade pass highways (Stevens, Snoqualmie, White Passes) had extended simultaneous closures during this period. The most snowfall occurred at Paradise and White Pass which averaged over a foot a day for two weeks! (I distinctly remember the tired voices each morning when talking to snow safety crews who had to battle this relentless snowfall.) The public was now paying more attention to the avalanche forecasts (see chart in sidebar) which may partly explain why no more avalanche deaths occurred during this time. But access to the Cascades was also restricted due to closed roads. The Northwest experienced an unusually cold spring with snow continuing to accumulate in April in the Olympics and Cascades. This led to record total snow depths in the south Cascades at White Pass and Mount Hood Meadows by May 1, leading to abnormal late season avalanche activity. Accident Summaries The following summaries provide short descriptions of the fatal accidents that occurred in the Cascades in the winter of 2007-08. Also provided are weather charts enabling readers to reach conclusions on their own. More complete accident reports are available on the Northwest Weather and Avalanche Center web site (www.nwac.us) and on the Westwide Avalanche Network web site (www.avalanche.org). I found writing about these accidents a sobering task. Not included in the summaries and statistics, a back country skier went missing on April 27 while skiing on the west side of Mount Baker, likely due to an avalanche or crevasse fall. The skier has not been found. Union Creek, December 2, 2007Kevin Carter, 26, Devlin Williams, 29, and Phillip Hollins, 41 were reported last seen descending into Union Creek Basin near Crystal Mountain ski area on Saturday, December 1, traveling via snowshoes and snowboards. By 11 a.m. on Sunday, 27 inches of new snow had fallen in the previous 18-hour period, accompanied by high winds, warming temperatures, and poor visibility. By Sunday afternoon rain began to fall up to an elevation of 7000ft and the avalanche danger was extreme. After the snowboarders were reported missing, Pierce County Sheriffs began a search and rescue operation on Monday, December 3. Initial response was slow because of strain on rescue crews due to flooding and other weather related emergencies throughout western Washington. Crystal Mountain ski area had to shut down because most of the shallow snowpack either avalanched or was washed away, and power and phone service were out for a time. When the weather began to clear on Tuesday, searchers confirmed that nearly all of the steep slopes in the area had released large climax avalanches running full path distances. Air and ground searches continued until Saturday, December 8, when a decision was made to suspend search operations until spring. On June 21, 2008, after periodic search efforts by members of the Crystal Mountain ski patrol and friends of the victims, the bodies of the snowboarders were found by a group of volunteers organized through the Turns-all-year backcounty skiers web site. The victims were discovered at 5420ft near the bottom of Union Creek Basin, buried in their sleeping bags and bivi sacks. Apparently they had hunkered down during the storm and were caught by an avalanche sweeping down from open slopes through the stand of 30 to 50-year-old cedars and silver firs where they had camped. (This information is from a report written by Paul Baugher, Chris Morin and Mark Moore after the recovery.) Weather charts are derived from data from NWAC weather stations at the Crystal Mountain ski area from November 30 to December 4. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Skier triggered slab avalanche in the Enchantment Lakes, April 24, 2008. Skier can be seen standing in the debris. Photo © Matt Peters. Enlarge |
Asa Mueller lends scale to a natural avalanche crown in White River Canyon, Mt. Hood, February 8, 2008. Photo © Tighe Stoyanoff. Enlarge | Thirty feet of debris from a control avalanche across the highway at Tunnel Creek near Stevens Pass, February 9, 2008. Photo © Mike Stanford. Enlarge |
| Reading the Hazards | ||||||
Washington’s 2007-08 winter season was unusual in that:
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| Heavy Snow Winter | ||||||
The chart below illustrates the snowpack growth at various locations in Washington and Oregon. The dates of the fatal accidents are indicated as follows: Snowdepth is in inches, timeline is marked off in two-week intervals. |
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| Fatalities Over the Years | ||||||
| The following chart shows annual Washington and Oregon avalanche fatalities for the past 30 years. Each bar represents the fatalities in a single winter season. Years without a bar had no fatalities. Average number of fatalities is about two per year. Data excludes the June 11, 1981, Mt Rainier icefall accident. | ||||||
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| The chart below records the total avalanche fatalities each month from the 1974-75 season to the 2007-08 season, ordered from September to August. December is the most deadly month with 19 deaths. | ||||||
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| NWAC Avalanche Warnings | ||||||
| The number of warnings issued by NWAC was quite a bit above average from December 2007 to February 2008 and again in May 2008. The following chart compares the warnings issued in 2007-08 compared to the monthly average. | ||||||
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| NWAC Website Visits | ||||||
Visitation statistics for the NWAC avalanche forecast web page (below) suggest that people do not pay as much attention to avalanche forecasts early in the winter as in mid winter. Perhaps the major avalanche cycle in early December 2007, combined with the fact that recreationists were less attuned to avalanche forecasts at that time, were factors in the fatalities this season. |
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