January 11, 1999 SOUTH COAST & VANCOUVER ISLAND REGION WEATHER: Warm, wet Pacific air flowed over the coastal ranges for the weekend, bringing rain to lower elevations and snow up high. A large and powerful low began to really hammer the area Sunday, taking the rain line all the way up to the 1900m level. Heavy rain and snow resulted. A brief clearing is forecast for Monday, and then more moisture from another system begins. Temperatures will remain above zero to at least 1500m. SNOWPACK: Although the lower snowpack is relatively strong, the weather has bounced around quite a lot since Christmas, forming a variety of crusts and problem layers in the upper snowpack. With the rain that will fall in most areas, and the heavy wet snow at higher elevations, these weaknesses will begin to fail. AVALANCHES: By Sunday afternoon, observers were seeing natural activity beginning to occur, and this is expected to increase in frequency and size as these low pressure systems flow over the area. DANGER: High TRAVEL ADVISORY: The systems are forecast to follow each other in wave after wave, so beware of a brief clearing trend. It won't likely last long. The worst conditions are likely to be found on Wednesday. NORTH COLUMBIA REGION WEATHER: The North Columbais saw plenty of snow and wind over the weekend. The arctic front retreated to around Prince George, and things warmed up fast. By Sunday afternoon, steady precipitation was falling, with the rain line creeping up the mountainside, eventually to around 2000m. Most observers reported a thin crust formed just as this moisture event began, making a slippery bed surface, which was then loaded with wet snow and rain. Weather forecasters predict clear breaks Monday, then another wet low tracks through. SNOWPACK: The snow that fell Sunday night was so wet it registered twice the normal water content in areas like Revelstoke. The crust that began the snowfall event produced a poor bond, and the subsequent snow came off easily. At upper elevations, easy shears were present before the moisture began, and these will be a failure plane in the upper start zones near mountaintop. AVALANCHES: Naturals to size 2 began to run Sunday afternoon, as the storm began. This activity increased overnight, in both frequency and size. The second wave of moisture Tuesday and Wednesday has forecasters expecting additional activity at least till mid week. Some out of bounds skiers took a ride Monday morning near Kamloops when they jumped into a slope of new powder from a cornice above. DANGER: High TRAVEL ADVISORY: The snow and rain is somewhat spotty in this system, so not all areas got huge dumps. With a warm, wet system like this, avalanche activity will be fast and furious, then taper off quickly. Right now, weather forecasters are predicting things to cool off Thursday, but expect highway closures and dangerous backcountry travel until the second low has passed. SOUTH COLUMBIA REGION WEATHER: The South Columbias did not see the arctic air which weather forecasters expected. Instead, the cold front retreated northward to near Prince George. Some new snow arrived on the weekend, and winds picked up, as a warm, wet low came onshore Sunday. Most of the moisture fell in the northern parts of this region, although winds were brisk throughout. Although most parts of the region stayed fairly dry, Kokanee Glacier Park got a localized dump of 38cm in 24 hours Sunday, and it was still snowing as this was written Monday morning. SNOWPACK: The upper snowpack has a series of crusts, which are adding strength, but also forming a bedding plane as new snow falls on top. By Monday, most observers were reporting only about 20cm of storm snow, although temperatures were rising to near zero. Upper elevation terrain features are being loaded by wind transport, and the warm temperatures are promoting slab formation. Some observers are still finding surface hoar on north slopes down almost a metre now. Kokanee Park had easy shears in the new snow at 31 and 60cm. AVALANCHES: Kokanee Park had widespread natural activity in the alpine. Elsewhere, natural activity to size 2 Sunday night, from steep terrain only. Explosive control work was producing results on the western slopes of Kootenay Pass, but size was small and the slides would often stop higher in the path. DANGER: ABOVE TREELINE - Considerable BELOW TREELINE - Moderate TRAVEL ADVISORY: Weather forecasters are predicting the second wave of moisture will be concentrated in the North Columbias, missing the majority of the South Columbias. If the system tracks south instead, expect the danger to increase accordingly. The localized storm in the Kokanee Park area has produced increased danger there from the rapid new snow loading. ROCKIES REGION WEATHER: The cold air mass dominating the central prairies has affected the Rockies as well. Some areas saw an upslope storm come in from the east Saturday, dumping up to 40cm of new snow in the Maligne Lake area of Jasper National Park, but less than 10cm in K Country. Wind has plagued the whole region since Sunday, transporting snow into lee areas. Warm temperatures in the Alpine from a temperature inversion have promoted slab formation up high. SNOWPACK: The new snow is not well bonded to the old snow surface in some areas. Easy shears persist in the upper snowpack. Shallow snowpack areas now have some depth hoar development from the cold weather. AVALANCHES: Scattered activity to size 2 is being reported throughout the region. Two backcountry snowmobilers took a scary ride in the Elkford area, with one completely buried except for a glove. This slide started in steep terrain on a shear in the upper 15cm of the storm snow, then stepped to ground on depth hoar. DANGER: ABOVE TREELINE - Considerable BELOW TREELINE - Moderate TRAVEL ADVISORY: Shallow snow areas are going to become increasingly dangerous. The majority of the Rockies snowpack is still quite strong, but depth hoar is now lurking where the snow is not as deep. The Rockies snowpack is notorious for triggering in shallow areas and propagating into deeper snow on more stable slopes, so use caution in transition areas.