January 3, 2003 SOUTH COAST REGION WEATHER: Most areas of the South Coast mountains received another 20 to 30 cm of snow by Friday morning, with strong to extreme Southerly winds and warming to mid-mountain elevations. Another system is expected late Friday and into Saturday with moderate to heavy precipitation and freezing levels again rising to near 2000m. This will be followed by yet another warm moist system on Sunday and Monday. SNOWPACK: Stiff dense windslabs have formed over slightly less dense snow from earlier in the storm. With the windy conditions, windloading has been most intense lower in the avalanche start zones, particularly near treeline, with windslabs up to 90 cm thick being reported. Weak layers within the storm snow stressed by precipitation, strong winds, and warm temperatures are the main concern at present. A surface hoar layer is now buried 70 to 100 cm in most areas, and the early season crust / facet layer is now down 90 to 150 cm. AVALANCHES: Widespread natural and human triggered avalanches have been reported at all elevations. These have mostly involved the recent storm snow, but some avalanches have released as deep as the early season crust / facet layer. Avalanche activity is expected to continue through the weekend and into Monday. Expect an increase in the number of large avalanches that release on the deeper buried weak layers. FORECAST OF AVALANCHE DANGER UP TO MONDAY EVENING (January 6) ALPINE ^Ö High with periods of Extreme Danger TREELINE - High BELOW TREELINE - High TRAVEL ADVISORY: Steep terrain at and above treeline that has not already avalanched in the current storm should be avoided. Also, in many areas windslabs have even built below treeline. NORTH COLUMBIA REGION WEATHER: North Columbias have received moderate to strong South to Southwest and 25 to 50 cm of storm snow up to Friday morning. Temperatures are forecast rise through the weekend, with freezing levels expected to reach 1800 m in the South and 1500 m in the North on Saturday. Moderate to heavy precipitation is in the forecast for Saturday and again for Sunday ^Ö Monday, with strong to extreme Southerly winds accompanying each precipitation event. SNOWPACK: Unstable windslabs have formed on most Northwest through East facing slopes. Observers report easy shears on the pre-Christmas surface hoar layer buried between 60 and 100 cm and moderate to hard shears on the deeper crust / facet layer from early winter. Expect the snowpack to remain in a very volatile unstable state through Monday, when temperatures are finally expected to cool down by January 9 and 10. AVALANCHES: Widespread natural and human triggered avalanches are occurring on all aspects with fracture depths up to 100 cm. This cycle is expected to continue through the weekend with ongoing precipitation, winds, and warm temperatures. Below treeline areas have been rain-soaked in many areas, and avalanches are expected where the recent storm snow overlies the surface hoar layer from before Christmas. FORECAST OF AVALANCHE DANGER UP TO MONDAY EVENING (January 6) ALPINE ^Ö High TREELINE - High BELOW TREELINE - High TRAVEL ADVISORY: Travel in avalanche terrain is not recommended. Times of Extreme Danger may occur during warm periods of intense precipitation. Conditions are highly unstable, and are expected to remain so until significant cooling occurs by Wednesday of next week. Careful observations over the next week will be important for terrain selection / decision-making later in January. SOUTH COLUMBIA REGION WEATHER: As of Friday, most areas have received an additional 30 to 60 cm of snow since the New Year. Freezing levels rose briefly to around 1500 m early Friday, and are forecast to rise again to around 1800 m over the weekend, as another 2 waves of precipitation cross the region. Strong to extreme Southerly winds are forecast to accompany these systems, with slight cooling and a shift to Westerly winds between storms. SNOWPACK: Dense windslabs have formed on most Northwest through East facing slopes, overlying lower density snow from earlier in the week. These are loading a buried surface hoar layer down 60 ^Ö 80 cm to the critical point. In addition, the deeper crust / facet layer from early winter is still weak, and may become problematic as the load continues to increase at warm temperatures. AVALANCHES: Numerous natural and human triggered avalanches on all aspects have been reported releasing on the buried surface hoar layer as of Friday morning. These reports include avalanches starting below treeline in some cases. This cycle is expected to continue through the weekend and into Monday, as the weather remains warm and windy with continuing precipitation. FORECAST OF AVALANCHE DANGER UP TO MONDAY EVENING (January 6) ALPINE - Extreme TREELINE - High BELOW TREELINE - High TRAVEL ADVISORY: Travel in avalanche terrain is not recommended until temperatures cool down and the natural avalanche activity subsides. It is expected that many slopes will stabilize by avalanching naturally during this storm cycle. Once things cool down again, it will be important to know which slopes have avalanched and which have not, so careful observation and attention to reports will be valuable later on. KOOTENAY BOUNDARY REGION WEATHER: Much of the West Kootenay received another 20 to 30 cm of snow Thursday night, with strong to extreme South to Southwest winds. This brought storm snow totals close to the 50 cm mark for the period ending Friday morning. Further warming is forecast with the next system on Saturday, and again on Sunday with freezing levels reaching 1800 to 2000 m. Strong Southwesterly winds are expected to continue through the weekend, accompanying periods of moderate, locally heavy precipitation. SNOWPACK: Observers report windslabs up to 60 cm thick on Northwest through East aspects at treeline. Weak interfaces within the snow that has fallen since Christmas are the main concern. Some areas report an ice crust formed by freezing rain on Dec. 30 that has been problematic. The pre-Christmas surface hoar layer does exist in many parts of the region, and observers report moderate shears on it. AVALANCHES: Both natural and human triggered avalanches are being reported, mostly releasing within the recent storm snow with fracture depths in the 20 to 40 cm range. Most of this activity has been on North facing slopes, but the potential for human triggering exists on all aspects. Propagation has been very evident Friday. FORECAST OF AVALANCHE DANGER UP TO MONDAY EVENING (January 6) ALPINE - High TREELINE - High BELOW TREELINE - Considerable TRAVEL ADVISORY: Recent winds have produced widespread areas of unstable windslab, and avalanche danger will remain high through the weekend as the storm track continues to generate precipitation and wind at warmer than average temperatures. SOUTH ROCKIES REGION WEATHER: Storm snow has continued to accumulate in the South Rockies, with many areas receiving an additional 20 cm overnight Thursday to bring storm totals up to between 40 and 60 cm since the New Year. Freezing levels rose to around 1500 m early Friday morning, but dropped down to around 1000 m by afternoon. Renewed warming is expected over the weekend along with another wave of precipitation late Saturday and into Sunday, with freezing levels again reaching the 1500 m level. Moderate Southwesterly winds are expected to continue through the weekend. By Monday, the storm track is forecast to be North of the region. SNOWPACK: The main concern in the region^Òs snowpack is the layer of surface hoar which overlies a facetted crust from the early winter. This weakness is now buried from 70 to 120 cm in the alpine, and observers report that this layer is very weak. With continuing precipitation, unseasonably warm temperatures and winds, this layer will certainly continue to plague the backcountry through the weekend and into Monday. AVALANCHES: Widespread human triggered avalanches and isolated natural activity have occurred through the day on Friday. In addition, strong winds and warm temperatures have built large, weak cornices which have been reported failing on Friday. Expect some natural avalanche activity through the weekend and into Monday, while human triggering of avalanches remains likely at all elevations through the period. FORECAST OF AVALANCHE DANGER UP TO MONDAY EVENING (January 6) ALPINE - High TREELINE - Considerable BELOW TREELINE - Considerable TRAVEL ADVISORY: Travel in alpine avalanche terrain is not recommended through the period. Avalanches larger than have been seen so far this season are expected, particularly on North and East facing slopes. Areas of unstable snow will exist on all aspects and elevations, so extra caution is warranted even below treeline.