Regions
Vancouver Island.
**Please respect the avalanche/patrol team and workforce at Mount Washington, at no time is uphill travel or unsanctioned use of the private property permitted.**
Mount Washington Avalanche control teams report triggering on all aspects between 1500 and 1300 meters numerous size 1 to 1.5 utilizing ski cuts and explosives, as well a couple of size 2 avalanches. These avalanches when trigger propagated widely and ran full path with good entrainment of the mass. These avalanches where all within the new storm snow (45cm total) and on terrain greater than 30 degrees.
Guiding operations reports a number of size 2 skier accidental avalanches on north and north west terrain in the backcountry outside of the ski area boundary. No details on elevation, involvement, or loss of gear.
Past Weather
A strong cold front passed over the forecast area Sunday, this system delivered 60 cm on the northwestern zones and 40 to 50 cm to the mid and south zones. In the wake of the storm temperatures cooled and winds subsided.
Weather Forecast
Predominantly clear conditions with daytime warming and sun. Expect warming to increase daily throughout the forecast period. Wednesday expect the northern zone of the forecast area to see precipitation and increasing South east wind with the southern zones receiving trace amounts of precipitation.**Monday:** No new precipitation Winds Strong backing to Light from the North West , Freezing levels at sea level rising to 600 meters. Temps at 1500 meters up to 3 degrees.**Tuesday:** Trace amounts of snow, Winds light to moderate from the South East, Freezing levels a t seas level with a day time high of 700 meters. Temps at 1500 meters up to 4 degrees.**Wednesday:** 1 to 5 cm , Winds Moderate to Strong from the South East, Freezing levels 600 meters with a daytime a high of 1000 meters. Temps at 1500 meters up to 4 degrees.
Terrain Advice
**Please respect the avalanche/patrol team and workforce at Mount Washington, at no time is uphill travel or unsanctioned use of the private property permitted.**Practice patience and allow time for new storm instabilities to stabilize prior to committing to any steep terrain.Plan routes and choose terrain that is low angle and supportive as you begin to venture into unmodified and uncontrolled snowpack and terrain. Identify and avoid travel either above or below cornice features. Adjust travel plans to ensure avoidance of solar aspects during warming and when the sun is out.
Snowpack Summary
New storm snow of up to 60 cm arrived on Sunday and this overlies a variety of surfaces. On isolated north aspects in the Alpine, surface hoar and on solar aspects a crust. 1500 meters and below, this new storm snow overlies a warm and moist surface.The upper snowpack continues to settle and a faceted decomposing crust combination can be found down 100 to 150 cm. This crust is producing sudden planar results during moderate testing and with a very large trigger such as a cornice fall could be triggered.The persistent slab from February is now down over 250 centimeters and is dormant and currently non reactive to testing. Below the snowpack is dense and well settled.
Snowpack Details
- Surface: New storm snow between 40 to 60 cm.
- Upper: Settled snow between 100 and 150 centimeters overlies a faceted and decomposing crust..
- Mid: Old unreactive crusts, overall dense and well settled.
- Lower: Well settled and dense.
Confidence
Moderate - Uncertainty with extend of wind distribution of storm snow , numerous reports, numerous forecaster field observations, and good weather model agreement.
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.
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.
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.