INTRODUCTION: 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, March 21st for the Glacier Park and Flathead and Kootenai National Forest areas. HAZARD ANALYSIS In the East and West Cabinets, between 5000 and 7000 feet of elevation, the avalanche danger is currently being rated as CONSIDERABLE on recently wind loaded slopes. Across the rest of the advisory area, between 5000 and 7000 feet of elevation, the avalanche danger is currently being rated as MODERATE. Below 5000 feet of elevation the avalanche danger is currently being rated as LOW. These danger ratings expire at midnight, Friday, March 21st. The avalanche danger could potentially rise by Sunday with increasing winds and availability of new snow to be wind transported. Because of the general nature of this advisory message, each backcountry party will always need to make their own time and site specific avalanche hazard evaluations. WEATHER ANALYSIS: Since Tuesday, light to moderate daily increases of snow water equivalent (SWE) have accumulated to gains ranging from .8 to 1.4 inches of SWE, with temperatures remaining in the twenties. Winds ebbed and flowed with passing squalls and high elevation ridge lines gained wind transported snow. SNOWPACK ANALYSIS: Our backcountry observations Thursday were from Patrol Ridge west of the Skyland Road on the Flathead National Forest and from Benning Mountain in the West Cabinets on the Kootenai National Forest. The new snow and continued cool temperatures are maintaining surface instabilities in the snowpack. During field obs in the West Cabinets a natural release was observed on an easterly aspect with an 18" fracture face which likely occurred prior to Wednesday. Across the region triggered releases are reflecting continued concern with interfaces adjacent to buried surface hoar and near surface facets. These failure interfaces are especially concerning the more shaded aspects. During this last period of Pacific impulses, easterly aspects have been protected from the early morning sun and are still maintaining near surface facets that have established with the cooler temps. Northerly aspects are still maintaining surface hoar deposits. New snow accumulations, both from new desposits and wind loading, have created the potential for easy triggers over this weak interface. A fracture line profile on Patrol Ridge confirmed such a scenario. The fracture line depth varied from 118 to 73 cms and ran over a decomposed buried surface hoar layer. This weak layer varied from smushed out to 3/4 of an inch thick. Observed crystal sizes at the failing interface were ranging from 12 to 24 cms in height. The approximate size of this slide was 80 to 100 yards wide by 150 yards deep. AVALANCHE - INSTABILITY DESCRIPTION: In the East and West Cabinets, between 5000 and 7000 feet in elevation, we are currently rating the avalanche danger as CONSIDERABLE, unstable slab layers are probable on steep recently wind loaded terrain. Natural avalanches are possible, while human triggered avalanches are probable. Backcountry travelers should be very cautious on recently wind loaded deposits. Be aware of potentially dangerous areas of unstable snow. Across the rest of the advisory area, between 5000 and 7000 feet in elevation, we are currently rating the avalanche danger as MODERATE, unstable slab layers are possible on steep terrain especially on shaded aspects. Natural avalanches are unlikely, while human triggered avalanches are possible. Backcountry travelers should use caution in steeper terrain on certain aspects. Below 5000 feet of elevation the avalanche danger is currently being rated as LOW, snow is generally stable with only isolated areas of instability. Natural avalanches are very unlikely, while human triggered avalanches are unlikely. Backcountry travel is generally safe. Normal caution is advised. WEATHER FORECAST & AVALANCHE OUTLOOK: ` Another Pacific weather system will move into Northwest Montana between late Thursday night and into Friday afternoon. This system will bring a few inches of snow to the mountains above 2500 feet. High pressure will build into the region behind this system Friday night and through the day on Saturday and into Saturday night. Another system will move in from the Pacific on Sunday. Although the new snow accumulations are only predicted for light to modest amounts, wind speeds will increase and vary in direction, with the passing of the next few systems. Recent wind loaded terrain will need alot of scrutiny at least by Sunday and into Monday. Shaded aspects especially, northerly exposures, will be further tested by Sunday with additional loading and could possibly trigger some natural releases. Warming with high pressure on Saturday and possibly solar heating could instigate easy triggers on any steep terrain by late afternoon on Saturday. Please note that this avalanche advisory is our best interpretation of snowpack 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. Anyone who wishes to improve proficiency with transceivers should check out the Beacon Training Center at The Summit of Big Mountain. A control panel allows individuals to build scenario's with previously buried transceivers in various configurations to test your skills in locating them. This cooperative effort by Glacier Country Avalanche Center, their funding partners and the Forest Service with additional help from the Big Mountain Ski Patrol has provided another tool for avalanche education. The next avalanche advisory will be on Tuesday, March 25th, 2008.