Idaho Panhandle Avalanche Center Backcountry Forecast Contact: Bob Kasun (208) 765-7414 or Kevin Davis (208) 265-6686, Ed Odegaard (208) 245-6209 This message available by calling (208) 765-7323 or toll-free at 1-866-489-8664. E-mail address: rkasun@fs.fed.us, kgdavis@fs.fed.us eodegaard@fs.fed.us Good Morning, this is Kevin Davis with the Idaho Panhandle National Forest Avalanche Center. This is the Backcountry Update for March 5th, with an outlook for the 6th and 7th, 2004. This report does not apply to local ski areas within the forecast region and will remain in effect through midnight, March 5th. WEATHER Sorry, put away the garden rake and break out the shovel again. No action visible on the region radar yet but we can expect precipitation in the form of snow above about 2,500 feet to develop later this morning. The weather service is predicting 2-3 inches of accumulation with this next front. Currently at 6:30AM the winds are blowing 25-30mph atop Schweitzer Mountain from the south/southwest. The temperature at 4,000 feet is 27 degrees Farenheit and at 6,000 feet it is 19. Down in the Lookout Pass area the SNOTEL is reporting temperatures in the low 20’s at slightly above 5,000 feet. Snow accumulations from the past several days amount to about 6 inches across our forecast region with areas of slightly more due to wind redistribution. Snowfall may abate some later in the afternoon today but snow showers will continue this evening with possible accumulations of an additional 2-4 inches by tomorrow. The outlook for Saturday is for a 60 percent chance of snow above 2,500 feet with accumulations of 1 inch. Watch for a slight warming with the passage of this Saturday morning front. Winds will continue to be gusty and a 60 percent chance of snow exists for Saturday evening. Sunday, more of the same. Winds strong out of the west/southwest, a 60 percent chance of snow above 2,500 feet, but slightly warmer temperatures. The weather that is predicted for the weekend will greatly increase the avalanche danger on a currently unstable snowpack. Selkirk and Cabinet Mountains Avalanche conditions in the Selkirk and Cabinet Mountains are rated as HIGH above treeline in areas of wind deposition. Natural and human triggered avalanches are likely. Avalanche conditions are rated as MODERATE below treeline on slopes greater than 35 degrees. Natural avalanches are unlikely while human triggered avalanches are possible. Backcountry travelers should use caution in steeper terrain on aspects where wind loading is evident. Snowpack Our pit tests in the Cabinet Mountains on Trestle Ridge revealed numerous weak layers in the pack associated with the ice crusts. The weakest layer we found 2 feet below the surface was a faceted layer above an old rain crust but it is currently bridged on southerly aspects by a 2 inch thick ice crust 1 foot below the surface. This weak layer will become a factor on southerly slopes as spring conditions begin to prevail. Our concern for the present is the 1 foot of new snow over the thick melt freeze crust. The bond was moderately strong and did not break clean on a southeast aspect but this layering on a north aspect was weak with surface hoar at the crust/new snow interface. New snow predicted for the weekend will place further stress on this weak layer and produce more potentially weak interfaces in new snow accumulations. Terrain Be suspect of steep exposed northerly aspects where surface hoar exists at the new snow/ice crust interface. Also, bridging is not stabilizing the pack on north slopes so assume that even small slabs could propagate to the lower weak layer. Avoid areas of wind deposition especially near ridgelines. With the new snow, changing temperatures, and high winds predicted for the weekend all aspects will have an elevated degree of avalanche potential. Saint Regis Basin region Avalanche conditions throughout the Saint Regis Basin region are rated as HIGH above treeline in areas of wind deposition. Natural and human triggered avalanches are likely. Avalanche conditions are rated as MODERATE below treeline on slopes greater than 35 degrees. Natural avalanches are unlikely, while human triggered avalanches are possible. Backcountry travelers should use caution in steeper terrain on aspects where wind loading is evident. Snowpack Carole found a slightly more sensitive pack on a southeast aspect especially at the interface of the new snow with the melt/freeze crust. A shovel shear produced a clean, easy shear. With a moderate pull she got another clean shear almost 2 feet down on another ice crust. Good potential for propagation to lower layers with the multiple weak layers. Terrain Carole’s main concern in the Basin is windloaded slopes. Although with the new snow the same caution is warranted. With the new snow, changing temperatures, and high winds predicted for the weekend all aspects will have an elevated degree of avalanche potential. St. Joe Mountain region Avalanche conditions throughout the St. Joe Mountain region are rated as HIGH above treeline in areas of wind deposition. Natural and human triggered avalanches are likely. Avalanche conditions are rated as MODERATE below treeline on slopes greater than 35 degrees. Natural avalanches are unlikely, while human triggered avalanches are possible. Backcountry travelers should use caution in steeper terrain on aspects where wind loading is evident. Snowpack On Breezy Point, at 4,800 feet, Ed O found sketchy conditions. The foot of new snow over the melt/freeze crust sheared very cleanly and easily. In fact, he didn’t even get to step on the block of his Rutcshblock test and it failed. All interfaces with numerous ice crust layers were breaking with moderate stress applied, but breaking fast and clean. Terrain With the new snow, changing temperatures, and high winds predicted for the weekend all aspects will have an elevated degree of avalanche potential. Be especially suspect of windloaded slopes near ridgelines. Avalanche conditions change for better or worse continually. Backcountry travelers should be prepared to assess current conditions for themselves, plan their routes of travel accordingly, and never travel alone. Backcountry travelers can reduce their exposure to avalanche hazards by utilizing timbered trails and ridge routes and by avoiding open and exposed terrain with slope angles of 30 degrees or more. Backcountry travelers should carry the necessary avalanche rescue equipment such as a shovel, avalanche probe or probe ski poles, a rescue beacon and a well-equipped first aid kit. Last updated: 03/05/04