As of Wednesday, Jan. 3, 2001
The new year is here but the old dry trend persists, at least for now. The past week has offered up little in the way of new snow as our persistent high pressure ridge continues to deflect the storm track up to the north and central coast. Concurrently, the ridge has drawn up warm sub-tropical air giving us high freezing levels. Combine all this with the recent high southerly winds and our backcountry snow conditions are about as bad as they get – but as they say in The Life of Brian , look on the bright side....
Snow stability has gradually been improving throughout this period. The surface hoar layers that are found in some lower elevation areas are rounding out under the warm temperatures. In the more coastal ranges (roughly from Mount Currie west) the November facet weakness continues to strengthen with a strong bridging layer above it in the "fat" leeward terrain. Areas where these deep weaknesses may still be a factor are shallow snowpack areas where the facets are still rather loose and weak. Such areas are generally wind exposed and may not have received the required load yet to perform.
Even the strong, deeper snowpack areas may be flanked by islands of shallow rocky areas known as "super weak zones." These zones of weakness have been known to provide the trigger point to propagate slab failure even through relatively strong adjacent snowpacks.
The more easterly ranges (i.e. Duffey Lake) have much less snow pack and consequently a far more significant facet weakness in the base. Travel in these shallow snowpack areas should be conducted with a higher degree of caution, particularly with any new snow or warming.
The weather forecast calls for a series of warm pacific frontal systems to increasingly affect our area. As I write this report we have light rain up to 1,600 metres, snow above with 100 km/h winds decimating the alpine and treeline terrain. This trend will continue into the weekend with the possibility of lowering freezing levels and increased precipitation amounts toward Sunday as the upper airflow is forecast to swing more westerly.
The avalanche danger scale is currently rated as CONSIDERABLE trending to POOR due to developing new snow instability. For daily Avalanche Danger Rating for regions adjacent to Whistler/Blackcomb ski areas call 938 7676.
For other regions, including the interior ranges, look at the Canadian Avalanche Centre Public Bulletin at www.avalanche.ca or call 1-800-667-1105.
