Weather Forecast
The wind should change to north by Tuesday morning as more high pressure moves across the interior. Clear skies and strong solar radiation is expected during the day on Tuesday, however northwest winds should help to keep alpine maximum temperatures close to -10.0 on shaded aspects. Some cloud and intermittent flurries are expected to develop in the afternoon or early evening that will bring a couple of cm overnight. Temperatures should drop down to about -12.0 in the alpine by Wednesday morning. The ridge of high pressure is expected to continue to bring clear skies and light winds during the day Wednesday. Expect valley cloud Wednesday morning. Alpine temperatures may rise above freezing on solar aspects, but should remain slightly below freezing on shaded aspects. The ridge is forecast to hold on Thursday as the next Pacific system approaches the coast. Precipitation amounts look low for Thursday evening at this time.
Avalanche Summary
Some sloughing in steep terrain on northerly aspects continues to be reported.
Snowpack Summary
About 2-3 more cm fell in most of the region on Sunday night or Monday morning. This brings the total amount of new snow to about 5-10 cm above the February 08 surface hoar and near surface facets. The wind has been very light during these recent flurries. Some areas have reported a very light freezing drizzle that had mixed with some rimed stellars to form a thin soft crust above the recently buried surface hoar layer(120208 SH). Warm alpine temperatures and solar radiation have developed a melt-freeze crust on southerly aspects in the alpine and on all aspects below about 1300 metres. There are a couple of layers that are buried between 25-35 cm that give resistant planar results from tests when hard forces are applied. Recent facetting in the top 20 cm appears to be rounding and bonding. The mid pack is generally well settled and well bonded. Deeper weaknesses in the snowpack are less of a concern; however, in the southern end of the region there is still talk of basal facets as some operators are avoiding thin and rocky alpine features. This represents a very low probability-high consequence scenario. Large cornices are also widespread in the alpine.
Problems
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.