Western Wyoming Avalanche Bulletin
Christmas weekend
by Bridger-Teton National Forest Backcountry Avalanche Hazard & Weather Forecast
December 24, 2009
The Bridger-Teton National Forest Backcountry Avalanche Hazard & Weather Forecast is posted daily online at www.jhavalanche.org. Interested people can sign up to get these reports by e-mail. The Bridger-Teton National Forest Avalanche Center posts area specific avalanche advisories by about 7 AM daily and an advisory for Westerm Wyoming is posted by about 5 PM daily from early November to late April. Funding for the center is provided by the United States Forest Service National Avalanche Center, the Bridger-Teton National Forest, the Jackson Hole Mountain Resort, and other local businesses and individual sponsors. For further information call 307-733-2664. To report an avalanche observation call 307-739-2607.
Continental Divide Trails/Togwotee Pass
The general avalanche hazard remains MODERATE above an elevation of 8,000 feet. In steep avalanche prone areas unstable slabs, one to two feet deep, lie upon a base of weak, faceted snow. These slabs could be triggered on approach by a skier or snow machine or after a slope has been crossed multiple times. Evaluate terrain and snow stability carefully. At the lower elevations, where there is significantly less snow, the general avalanche hazard is LOW.
Southwest Trails/Greys River Area
The general avalanche hazard is MODERATE above an elevation of 8,000 feet. Areas of unstable snow persist and remain sensitive to human triggers. Soft and hard slabs up to 30 inches in depth lie upon a base of weak, faceted snow. These slabs could be triggered on approach by a skier or snow machine or after a slope has been crossed multiple times. Those who make bold terrain decisions could incur severe consequences. At the lower elevations, where there is significantly less snow, the general avalanche hazard is LOW.
Teton Area
Stiff slabs lie upon a base of weak faceted snow. These slabs are sensitive to human triggers. Multiple human triggered avalanches occurred this week on steep avalanche prone slopes in the Southern Teton Range. All of these avalanches failed on depth hoar that formed earlier in the season. This snowpack structure is prevalent throughout the region at the mid and upper elevations (7,500 to 10,500 feet).
The general avalanche hazard is expected to be MODERATE above an elevation of 8,000 feet. Areas of unstable snow persist and will continue to be sensitive to human triggers. Humans who venture onto steep avalanche prone slopes could trigger a hard slab avalanche one to three feet deep. These slabs could fail on approach or after a slope has been crossed multiple times. Those who make bold terrain choices could incur severe consequences. At the lower elevations the general avalanche hazard is LOW and avalanches are unlikely.
TREND FOR CHRISTMAS WEEKEND, SATURDAY AND SUNDAY
Temperatures will remain cold with areas of fog and low stratus clouds forming in the valleys at night and lingering through the morning hours. Unstable areas will continue to be sensitive to human triggers.
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