Regions
Vancouver Island.
No new avalanche activity has been reported over the past few days.
Past Weather
Small amounts of snowfall Friday were replaced with light rain Saturday. Sunday the temperatures went above zero at below treeline and near zero at treeline. Rain at these elevations resulted in a freezing rain ice crust and began to moisten the upper snowpack. Only the very high (above 1700m) has escaped the rain effects.
Weather Forecast
Sorry folks.. It does not look good for the next three days... Wet wet then freeze... Monday - 3 to 10 mm of precip (mix of snow and rain), winds moderate SW rising to strong S to SW, temps 0 to -3, freezing level 1000 m to 1500 m. Tuesday - Oh here it is! 25 to 45 mm of precip (mainly all rain at all elevations), winds moderate SW rising to strong SW overnight, temps +1 to +5 (ouch!), freezing level 2500 m to 2000 m. Wednesday - 3 to 20 mm of rain fallowed by 2 to 5 cm of snow as temps drop mid day, winds strong SW dropping to moderate SW, temps +2 to -6, freezing level 1500 m to 800 m
Terrain Advice
Avoid thin shallow areas at treeline and alpine elevations, especially on northern aspects. These spots have a much higher likelihood of triggering the mid snowpack weak layers.Watch for hazards such as rocks and open creeks at below treeline elevations, due to the very shallow snow pack. Very little snow down low means low avalanche danger but many dangers exist hidden just under the surface.... Stay away from all avalanche terrain at treeline and alpine elevations when the rain starts to fall as the rain will certainly result in loose wet avalanches and potentially wake up buried weak layers and result in large avalanches.
Snowpack Summary
Rain up to 1700m has moistened the upper snowpack, while the mid snowpack remains dry with a few preserved weak layers. So we have a nasty upside down cake (heavy over weak).
Snowpack Details
- Surface: Thin rain crust from a freezing rain event Sunday in the below treeline and treeline elevations
- Upper: Moist snow approx 10 to 20 cm down depending on elevation
- Mid: A few preserved weak layers in dry snow
- Lower: Mainly well settled and bridged, but a weakness near the ground from early season still exists.
Confidence
High - Weather models in agreement and good field data.
Problems
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.
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.