ZCZC SLCWRKSNW TTAA00 KSLC 262332 Good afternoon, this is Tom Kimbrough with the Forest Service Utah Avalanche Forecast Center with the avalanche and mountain weather bulletin for the Salt Lake area mountains. Today is Thursday, December 26 and it's 2:30 pm. This bulletin is brought to you in part by a generous donation from the Employee Owners of Black Diamond Equipment, manufacturers of backcountry ski equipment, Scarpa Terminators and Bibler Tents, available at the Black Diamond retail store in Salt Lake City at 2084 East and 3900 South. (Ogden 3701 Washington Blvd.) (Provo: This recording is made available to you courtesy of BYU Outdoors Unlimited. The information contained in this bulletin is from the U.S.Forest Service which is solely responsible for it's content.) It's a manky sort of day out there and the avalanche activity is picking up fast. Snow has continued to fall above 6,500 feet most of the morning with accumulations of several inches at 9,000 feet in the Salt Lake mountains. More snow has fallen up north, maybe as much as 12 inches in places since this morning. Winds are also blowing, coming around to the west and southwest and starting to increase. Not really much of a break in storms, I'd say. The wind is doing it's usual job, drifting snow and building slabs. Avalanche workers are reporting cracking in the surface snow and control work at some areas produced fairly widespread slides in last night's new snow. Ski cuts are now resulting in slides about 12 to 18 inches deep. Many areas had a surface wind or rain crust that formed yesterday, on which a couple of inches of light density snow fell yesterday afternoon. This layering is having trouble supporting last night's and today's heavier snow. Slides from control work were mostly shallow but a few pockets broke two feet deep. There were also two control work slides into old snow reported. One was from near Mt. Ogden and the other was north of Park City. These were both about 3 to 5 feet deep and 150 feet wide. One was north facing and the other east and southeast, both at about 9,000 feet and 35 degrees or steeper. With strong winds continuing and even increasing and more snow in the forecast for tonight, the avalanche danger will also be going up. The instability in the new snow will be the most obvious and easiest to deal with. Shooting cracks and whooming sounds may be good clues to look for. Wind drifted slopes may break several feet deep just in the new snow on Friday. I am also concerned that in some areas, buried layers of weak faceted snow may be getting overloaded again. This problem is likely to be worse out of the upper parts of the Cottonwood Canyons. The Logan and Ogden mountains have received more snow from both last weekend's storm and so far from this one as well. The Provo mountains haven't picked up much new snow yet but the winds are howling down there and they may have the weakest snow pack in the Wasatch. The Park City mountains are somewhere in between but have already had one explosive released deep slab. These deep slab problems are probably best dealt with in the backcountry by keeping your slope angles under 35 degrees. The danger of human triggered avalanches is already high on steep wind loaded slopes and we are likely to see some natural activity tonight and Friday if the snow and wind continue. The danger will be moderate to high on slopes less steep than 35 degrees and on wind sheltered slopes. Cornices are large and sensitive. The lower elevation snowpack is also weak and unstable. Be cautious of steep northerly facing slopes below about 7,000 feet, especially today with rain and very wet snow falling down there. This the kind of terrain that snow players and snowshoers are likely get into. Ogden and Logan area mountains: High on steep wind loaded slopes and steep slopes at lower elevations. Mountain weather: Several impulses are rolling in on a westerly flow with plenty of associated tropical moisture. The mountains will have snow at times tonight and tomorrow with a snow level between 6,000 and 7,000 feet. Winds will be very strong over the ridges, 30 to 40 with gusts to 60 and 70. Temperatures will be a little cooler on Friday with highs near 30 degrees. To report avalanche activity and snow conditions call us at 524- 5304 (or 1-800-662-4140) This bulletin and a detailed mountain weather forecast is available on the Internet at www.avalanche.org. Remember that this bulletin offers only generalized avalanche information and you are ultimately responsible for your own safety. The Utah Avalanche Center is brought to you by the Forest Service in partnership with the National Weather Service, the State of Utah, Salt Lake County and the Friends of the Utah Avalanche Forecast Center. I will update this bulletin on Friday morning by 7:30 am. Thanks for calling. Kimbrough