Salt Lake Avalanche Advisory Thursday, February 23, 2012 Created at 5:58 am Forecaster: Bruce Tremper AVALANCHE WARNING » Dangerous avalanche conditions are occuring or are imminent. Backcountry travel in avalanche terrain is not recommended. Notice: An avalanche warning is in effect for the mountains of northern and central Utah. Very strong winds at all elevations combined with dense snow created a HIGH avalanche danger on many slopes. Avalanches may occur in unusual areas. Especially avoid any steep slope with recent wind deposits. BOTTOM LINE There is a HIGH avalanche danger today on many slopes. Avalanches will occur in unusual places. Choose very conservative terrain today. Stay off of and out from underneath any slope steeper than 30 degrees. CURRENT CONDITIONS Wow, it was a wild, little cold front. Winds nuked yesterday afternoon and overnight blowing from the west and northwest 40, gusting to 60 mph on most of the ridge tops with gusts to nearly 100 at very exposed locations. Winds blew hard at all elevations. Very dense graupel fell with the front, which added an additional inch of water weight in only about 3-4 inches of snow making the density a hefty 20 percent. But the cold front is passed and winds have died down and skies are clear. Temperatures have plummeted into the single digits along the ridge tops. Since it was so warm yesterday, expect lots of ice at elevations below about 7,500' I'm guessing that riding conditions will be fairly poor today. RECENT ACTIVITY There was quite a bit of natural activity yesterday within the new snow along with some deeper releases to depth hoar with explosives in uncompacted terrain. In addition, there was one burial in the Logan area mountains with sketchy details but it sounds like they rescued themselves and they are OK. In addition there was another close call in Logan yesterday. THREAT #1 Expect to find dense, hard, wind slabs on many slopes, even in unusual areas like off the sides of mid elevation gullies. Since the wind blew so hard, the slabs will be in unusual places, such as well down off the ridges. In addition, the new snow was graupel,--that Styrafoam ball type of snow--which is notorious for rolling off steeper terrain and pooling at gentler terrain at the bottom. So watch our for what we call "graupel pooling" where deep, dense deposits can accumulate at the base of the steeps. THREAT #2 Remember there are monsters in the basement. The wet, warm, windy conditions have added over 3 inches of water weight in the past 4 days with over an inch added last night in an intense burst. Every time you load the deeper weak layers with significant weight, they get reactivated and I would expect that a number of avalanches probably released last night or will today with explosives or the weight of a person. Stay on very conservative terrain today--meaning stay off of and out from underneath slopes steeper than 30 degrees. MOUNTAIN WEATHER The storm is over. We should have clear to partly cloudy skies today with winds from the northwest 10-20 mph. Temperatures will be cold, in the single digits. Friday, should be about 10 degrees warmer with continued clear to partly cloudy. We will have another windy, cold front on Saturday afternoon into Sunday with perhaps 8 more inches of snow.