Regions
Vancouver Island.
Confidence
Moderate - High variability between forecast precipitation amounts and freezing levels with current weather models.
Travel & Terrain Advice
Avoid avalanche terrain when rapid warming and rain on snow events are forecast. Give a wide berth when travelling either above or below cornices.
Avalanche Summary
No new natural avalanches have been observed and ski testing has not produced any significant results in the past 48 hours.
Snowpack Summary
A strengthening melt freeze crust has developed over the last 72 hours and continues to build strength as temps have remained low and today very little solar effect was present. The surface melt freeze crust dominates the upper snow pack and can be found on all aspects and at elevations up to 1700 meters. The March 22 melt freeze crust can be found down from 15 to 45 cm and is producing hard resistant planar results when tested. Mid and lower snow pack is well settled and dense.
Snowpack Details
Surface: Well established melt feeze crust. Upper: a Melt freeze crust buried down between 10 and 50 cm. Mid: Well settled. Lower: Well settled.
Past Weather
An arctic high pressure to the north of the region has brought to the forecast area below seasonal temperatures with light snow fall and light south west wind. Freezing levels have fluctuated between near seas level overnight and 1200 meters by mid day.
Weather Forecast
A westerly flow will enter the region late Wednesday bringing to the forecast area, rising freezing levels and temperatures, moderate precipitation amounts and moderate to strong south east wind. Western zones will receive substantially more precipitation and warmer temperatures with inland and eastern zones slightly cooler with less wind and precipitation. Wednesday: 0 to 5 cm new snowfall temps -1 to 3, winds light south east, freezing level 600 m rising to 1200 m mid day. Thursday: 10 to 20 cm of snowfall followed by 5-15 mm of rainfall late afternoon temps 0 rising to +3.5, winds moderate south east, freezing level 1000 m rising to 1700 m near days end. Friday: 10 to 30 mm of rainfall temps +3 to +6 winds moderate south east , freezing level 1700 m rising to 1800 m mid day.
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
Wet Slabs
Wet Slab avalanches are the release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slabs can be very unpredictable and destructive.
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.