Regions
Vancouver Island.
Confidence
Moderate- few snowpack observations, especially alpine. weather models in agreement.
Travel/Terrain Advice
Winter version 5.0 is on its way during our season of fluctuating spring/winter conditions. Last Saturday's rain and Sunday's warm temps have essentially reset our snowpack, so the main thing to be wary of is where the new snow is falling and being transported to with the winds. Watch for loaded slopes and bowls and study how well the new snow is bonding to the old. Be especially cautious of route choice later in the day Wednesday with the temperature spike increasing the likelihood of triggering an avalanche in the new snow.
Past Weather
Very high freezing levels (up towards 3000 m) accompanied light to moderate rain Saturday, right to to top of our island summits. Sunday things cleared up and brought very warm temperatures to the unseasonable range of 10 degrees on the slopes. Spring skiing conditions everywhere.
Avalanche Summary
Saturday's warm temps and rain created a flurry of avalanche activity on all aspects and elevations, producing numerous loose wet slides triggered both naturally and human. Those reported were fortunately in the size range of only 1-1.5, but we could expect some in the alpine were greater, if we had any alpine observations.
Snowpack Summary
Surface - A thin new melt freeze crust has been forming overnight in the alpine and open high treeline with day time temps decomposing it. Upper - Rain and warm temps have resulted in rapid settlement of the upper snowpack. All elevations and aspects are now moist (with solar aspects going wet during Sunday's sun and warm temps). Mid - As temps and freezing levels begin to drop, the moist well settled upper snowpack will tighten and all but eliminate any concerns of the mid Jan, Dec and Nov crusts.Lower - Well settled.
Weather Forecast
Mild temps and light rain Monday into Tuesday will ease into light snowfall. Strong south westerly flows will flush out the unseasonably warm weather, bringing us a new strong pacific storm late Wednesday into Thursday with significant snowfall. The new system will arrive with a short lived spike in temperatures and strong south east winds. Expect cloudy conditions over the forecast period so be prepaired for more difficult route finding in unknown terrain.Mon - 8-20 mm of rain. Winds moderate from the south east.Freezing levels of 3000-1700 mTues - 8-14 mm of rain and 5-15 cm of snow. Winds light to strong south east. Freezing levels of 1600-500 mWed - 30-50 cm of snow and 10-20 mm of rain. Winds moderate to strong south east.Freezing levels of 700-1500 m
Problems
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.