Avalanche Forecast
Issued: Dec 27th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
trettie,
Avalanche Canada
Carefully assess the bond between the new snow and the underlying crust. There is uncertainty in the thickness and elevation of the new crust as well as the bond between it and any new snow that falls.
Summary
Confidence
Avalanche Summary
No new avalanches were reported on Monday.
On Sunday, observations remained limited but included several size 1 loose wet avalanches and a size 1.5 wet slab avalanche.
On Saturday, limited observations during the storm included numerous natural loose wet avalanches up to size 1.5 and several natural slab avalanches up to size 2. These slabs were up to 40 cm thick and were typically releasing at around treeline elevation. Some of these slabs were triggered by loose wet avalanches in motion.
Snowpack Summary
Rain has recently soaked the surface at all elevations. As freezing levels drop a thick surface crust will form. This crust will likely extend to mountain tops. Precipitation has likely fallen as snow over this layer above 700m.
Before the rainfall, new storm snow buried a highly variable old surface which included an unsupportive sun crust on southern aspects, spotty surface hoar in sheltered terrain, and heavily wind-affected surfaces in wind-exposed terrain.
A layer of decomposing surface hoar crystals could be found down 70 cm prior to the storm. There is also a layer of weak, sugary facet crystals near the base of the snowpack. During recent testing, both of these layers were producing hard results and there have been no recent reports of avalanches occurring on these layers. However, the current storm loading will test these layers and there still remains potential for avalanches in motion to step down to these older layers.
Overall, the snowpack continues to present as thin and averaged 130 cm deep at treeline prior to the storm.
Weather Summary
Tuesday Night
Light flurries bringing up to 5cm of new snow. Light west winds and freezing levels falling to around 1000m.
Wednesday
Mainly cloudy with light flurries bringing trace amounts of new snow to the north and up to 10cm to the south. Light variable winds. Freezing levels falling to 400m by the evening.
Thursday
Stormy with 15 to 30mm of new precipitation . Strong southeast winds and Freezing levels rising to 1300m.
Friday
stormy with 5 to 30mm of new precipitation expected. Light southwest winds and freezing levels rising to 1500m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Give the new snow time to settle and stabilize before pushing into bigger terrain.
- Make observations and assess conditions continually as you travel.
- Be alert to conditions that change with aspect and elevation.
- Closely monitor how the new snow is bonding to the crust.
Problems
Storm Slabs
As temperatures continue to fall, new snow will likely form slabs over the new crust. Carefully assess the bond between the new snow and this crust as you gain elevation.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 28th, 2022 4:00PM
