January 19, 2009 Avalanche Advisory

Posted: 07:00 January 19, 2009

Good morning. This is Dudley Improta with the West Central Montana Avalanche Center’s avalanche advisory for January 19, 2009. This information is the sole responsibility of the Forest Service and does not apply to operating ski areas. The avalanche danger rating expires at midnight tonight. Today’s advisory is sponsored by Becky Richards in memory of Ben Richards (pictured at the right).
The advisory area includes the Bitterroot Mountains from Lost Trail to Lookout Pass, the Rattlesnake Mountains and the Southern Swan and Mission Mountains near Seeley Lake. Detailed avalanche information about the St. Regis Basin can be found at the Idaho Panhandle National Forest Avalanche Center .

Weather and Snowpack Analysis
It has been warm at the higher elevations. We noted temperatures of 47 degrees Fahrenheit at 8000′ at 1pm on Sunday. Snow stability tests are showing stable conditions. Snotel sites around the region are indicating a settling snowpack with loss of snow depth. However, at the warmest part of the day we are seeing lots of snow on the move. At this time of the day snow is sluffing off the rocks, dropping out of the trees and moving on ski turns on the South slopes. So, for the next few days treat this as a spring snowpack. Be especially careful if riding or skiing steep rollovers or steep faces near rocks during the heat of the afternoon. There is the possibility a wet surface slab could trigger a bigger slide on the weak snow near the ground that we have been discussing for weeks.

Current Avalanche Danger
The avalanche danger is LOW Natural avalanches are very unlikely, human triggered avalanches are unlikely. Between 12noon and 3pm on slopes steeper than 30 degrees above 6000′ the avalanche danger is MODERATE due to very warm temperatures at altitude. Natural avalanches are unlikely, human triggered avalanches are possible.

Weather Forecast and Avalanche Outlook
Tonight through Wednesday a persistent ridge of high pressure will maintain a stable environment across Western Montana. Low clouds will remain in the valleys. High terrain will bask in the warm sunshine. The only possibility for snow looks like Wednesday night. We should keep an eye on any crusts that are formed by the warm temperatures when it does snow, but for now we have generally stable conditions.

If you have snow observations or any snow information you’d like to share please contact us at [email protected] .

The next avalanche advisory will be issued Friday January 23rd, 2009.