GNFAC Avalanche Advisory for Mon Feb 14, 2011 Good morning. This is Eric Knoff with the Gallatin National Forest Avalanche Advisory issued on Monday, February 14, at 7:30 a.m. This advisory does not apply to operating ski areas. Mountain Weather: Southwest Montana will receive a welcomed reprieve from the wind today as a ridge of high pressure builds over the region. Currently, winds are blowing out of the WSW at 15-30 mph and will continue at these speeds for the remainder of the day. Mountain temperatures are presently in the mid to high 20s and will rise into the 40s under mostly sunny skies. Another round of wind is expected to arrive tomorrow. Snowpack and Avalanche Discussion: The Bridger Range, The Madison and Gallatin Ranges, the Lionhead area near West Yellowstone, the mountains around Cooke City and the Washburn Range: Hurricane force winds have done a number on the snowpack over the past few days. Yesterday, wind gusts up to 100 mph were recorded at the Great Falls weather station at Moonlight Basin, while gusts in the 60’s and 70’s were the norm elsewhere. Winds of this magnitude have a tendency to blow more snow into the atmosphere than onto leeward slopes, but as Doug found out yesterday in Sunlight Basin, rapid loading was taking place in specific areas. Doug mentioned he observed repeat slides on the same slope due to intense loading. The Big Sky Ski Patrol also reported recent avalanche activity on Cedar Mountain. Non-wind loaded slopes appear to have a generally deep and stable snowpack. Fortunately, winds will abate throughout the day. As the winds drop so will the avalanche danger. Warm temperatures and the lack of an active weak layer will help conditions stabilize quickly. The main avalanche concern today will be any slope that has received a heavy wind load. Upper elevation slopes with north and east aspects will be the most likely to have unstable conditions. Today, heightened avalanche conditions exist on specific terrain features and the avalanche danger is rated MODERATE.