Bridger Teton Avalanche Center
WESTERN WYOMING AVALANCHE ADIVSORY
Issued on Tue December 10, 2013 8:00 PM
The upper level flow has backed to the west as the last of a series of Alberta Clippers passed to our east. Alberta Clippers are fast moving, cold storm systems that are generally moisture starved. They originate in Alberta and track southeast along the east side of the Continental Divide across the northern plans into the Midwestern states. Today’s Clipper brought several inches of new snow to the higher elevations during the morning hours.
During the past 48 hours temperatures at 10,500 feet have risen from minus 20 to the single digits above zero. Winds during the past 48 hours have backed from the northwest to the west with average speeds of 15 to 25 and gusts to 40 miles per hour. These winds have redistributed the loose snow and have formed pockets of dense wind slab on leeward aspects. During the past two days several slab avalanches have been triggered by backcountry skiers in steep terrain that likely involved this wind drifted snow.
FORECAST FOR Wednesday, December 11, 2013
Any leftover snowfall from today’s passing storm system is expected to end overnight. A flat ridge of high pressure will build into the region and bring mostly sunny skies to the region with light westerly winds. Temperatures on Wednesday will rise into the teens and 20s.
The general avalanche hazard is expected to be MODERATE at the mid and upper elevations (7,500 to 10,500 feet) and LOW below an elevation of 7,500 feet. At the mid and upper elevations slab avalanches up to three feet in depth could be human triggered in steep, wind loaded avalanche starting zones. On steep northerly aspects above an elevation of 9,000 feet these slabs could step down to the ground. The warmer temperatures may increase the sensitivity of these slabs to human triggers. Avalanches are unlikely at the lower elevations.
TREND FOR Thursday, December 12, 2013 AND Friday, December 13, 2013
Dry conditions are expected ahead of the next storm system which approaches the area from the Pacific Ocean on Friday. The general avalanche hazard is not expected to significantly change until the next storm system arrives.
For further information call 307-733-2664
To report an avalanche observation call 307-739-2607
SPONSORS: Togwotee Mountain Lodge, Box Y Ranch, Jackson Hole Mountain Resort, Brooks Lake Lodge, Wyoming State Trails Program, Bruce Hayse M.D., Wyoming Public Television KCWC, Storm Show Studios, Skinny Skis, Chippy's Kitchen and Catering, Apex Real Estate and Property Management, Teton Gravity Research, Snow King Resort, Idaho National Laboratory , Jackson Hole Mountain Guides, Grand Targhee Resort, DeFazio Law, Eric Balog, Twenty Two Designs, Jackson Hole Ski Atlas, Jackson Hole Snow Devils, Stewart Johnson, CPA, Exum Mountain Guides, Four Pines Physical Therapy, Backcountry Access, Grand Teton Floor & Window Coverings, Clif Bar & Company, Outdoor Research, Steve Romeo Memorial Fund, International Snowmobile Manufacturers Association and Voile