Avalanche Forecast

Fair - Forecast snowfall amounts are uncertain on Monday

The snow from Friday should have stopped by Saturday morning, leaving about 10 cm in the Nelson area and closer to 15 cm further south. Saturday should be mostly clear and a bit cooler, but still warm for this time of year. The freezing level is expected to be 700 metres on Saturday, and rising to 1000 metres on Sunday. The next system is forecast to hit the coast on Sunday. High cloud is expected to move in from the Northwest during the day, and may turn to snow by Monday morning. Forecast snow amounts are uncertain for Monday. Some models show the precipitation being confined to the coast.

The recent natural avalanche cycle continues to produce natural and human triggered avalanches up to size 3.0. These occurred on all aspects above 1700m with wide propagations, and crown depths up to 80cms. Many of these are failing on the mid-December surface hoar, mostly on north through east aspects from 1500m to the peaks. A skier remotely triggered an avalanche from 50m away and in many places shooting cracks and whumphing are further indicators of a very touchy, unstable snowpack.

The storm slab continues to develop. There is now 50-80 cm above the mid-december weak layer of surface hoar. The wind has been strong at times during the recent storms, and has built stiff wind-slabs in the alpine and at treeline on North, East and in some locations South aspects. Warm temperatures have developed a soft slab in the storm snow in areas that were not affected by the wind. The surface hoar layer continues to provide easy and sudden shears in tests. The mid-pack is generally well settled. Facets at the base of the snowpack have not been reactive recently.