This is Tony Willits, with the backcountry avalanche advisory issued by the U.S. Forest Service Glacier Country Avalanche Center at 8:00 AM, Friday, January 13th, 2006, for the Glacier Park and Flathead and Kootenai National Forest areas. HAZARD ANALYSIS Between 5,500 and 7,500 feet in elevation, the avalanche hazard is being rated as CONSIDERABLE. Unstable slab layers are probable on steep terrain. Below 5,500 feet in elevation the avalanche danger is being rated as MODERATE. These danger ratings expire at midnight, Friday, January 13th, 2006. The outlook through the weekend is for the avalanche hazard to remain near the current levels. Because of the general nature of this advisory message, each back country party needs to make their own time and site-specific avalanche hazard evaluations. WEATHER ANALYSIS: The region has received significant loading since Monday morning with most site recorded ranges from 2.0 inches to 5.0 inches of of snow water equivalent (SWE). Temperatures have been near freezing and into the low twenties. Snowfall accumulations since Monday have been ranging from 20 to 60 cms. Winds speeds on Tuesday night and Wednesday were strong from the south and southwest. SNOW PACK ANALYSIS: Our backcountry observations Thursday were on Peter's Ridge in the North Swan Range on the Flathead National Forest and Rattle Mountain in the West Cabinets on the Kootenai National Forest. An observation was posted on the web page for Wednesday that highlighted avalanche and wind activity in the Southern Whitefish Divide area. Wind action was apparent and cross loading on steep open slopes was observed as well as significant cornice buildups at the ridge tops. Inverted densities were noted in observation data with the surface snow being harder than the underlying layers. These softer underlying layers were buried from 20 to 30 cms and would vary with location as to elevation and aspect. Stress tests were revealing easy shears upon these layers. AVALANCHE - INSTABILITY DESCRIPTION: Between the elevations of 5,500 and 7,500 feet in elevation we are currently rating the avalanche danger as CONSIDERABLE, unstable slab layers are probable on steep terrain. Natural avalanches are possible, while human triggered avalanches are probable. Backcountry travelers should be very cautious in steep terrain. Be aware of potentially dangerous areas of unstable snow. Below 5,500 feet in elevation we are rating the avalanche danger as MODERATE. Unstable slab layers are possible on steep terrain. Natural avalanches are unlikely, while human triggered avalanches are possible. Backcountry travelers should use caution on steep, open, and unanchored slopes. WEATHER FORECAST & AVALANCHE OUTLOOK: A warm frontal boundary will pass through Western Montana and Central Idaho today, causing snow levels to gradually rise throughout the day. Consequently expect mainly snow across the higher terrain this morning transitioning to a rain/snow mixture by late afternoon. Saturday night a cold front will pass through the area bringing another round of accumulating snow to the high country. Winter weather highlights have been issued for both of these systems, so when you go to the National Weather Service Web Page a map will appear click on the portion of the map of which you have an interest and the winter storm warning that applies will appear. Snow accumulations will continue through out the weekend. Continued loading will only increase the risk of triggering an avalanche and naturals could occur as well. Back country travelers need to pay close attention to the steep open terrain especially in and around ridge tops with the recent strong winds. Winds will again kick in on Friday and with the snow accumulations expected, wind slabs will become more prevalent. Focus on travel on terrain that is less than thirty degrees and especially avoid lee side of ridges or north and northeast facing slopes. The next regularly scheduled update of this advisory message will be on Tuesday, January 17th, 2006. Please note that this avalanche advisory is our best interpretation of snow pack conditions and National Weather Service forecasts on the day the advisory is issued. Unanticipated weather changes such as wind, a marked temperature increase, or precipitation beyond forecast amounts can increase the avalanche danger. Local variations may also exist.