Avalanche Forecast
Issued: Dec 18th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs and Loose Dry.
JA,
Avalanche Canada
Extreme cold temperatures for the next few days - keep this in mind as any incident or equipment failure may lead to severe consequences.
We have switched Jasper's main avalanche problem from a persistent slab to a deep persistent slab. The persistent slab has not gone away but any avalanche triggered in the upper snowpack will likely step down to weak facet crystals on or near the ground resulting in large avalanches.
Summary
Confidence
Moderate
Avalanche Summary
No new avalanches have been observed or reported on the icefields parkway. On December 14th in the Parker Ridge/Mt. Saskatchewan area, a couple of natural avalanches to size 2 were reported stepping down to ground in the alpine.
Snowpack Summary
2-5 cm of snow fell on December 17th and has buried a surface hoar / facet layer in sheltered areas at tree line and below. In the alpine, surface conditions are variable with a mix of hard wind pressed snow and facets. A persistent weak layer is down 25-35cm specific to tree line and below in sheltered areas. The bottom of the snowpack is weak consisting of basal facets with pockets of depth hoar. The snowpack height ranges from 40-100cm. Snowpack is unsupportive tree line and below.
Weather Summary
An Arctic ridge will bring extreme cold temperatures and dry conditions through the week. Winds will be light from the northeast. No significant precipitation is expected during the forecast period.
Terrain and Travel Advice
- Uncertainty is best managed through conservative terrain choices at this time.
Problems
Deep Persistent Slabs
The lower snow pack is becoming weak and faceted due to the cold temperatures. Any weak layers in the upper snowpack will likely step down to this "deep" layer on or near the ground. Below tree line hazard is rated low but caution is advised in isolated steep open slopes with signs of the upper snow pack becoming a stiffer slab due to wind.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
A recently buried Surface hoar / facet layer will make the dry loose avalanches likely in steep terrain. Be on the look out for a recently buried sun crust on solar aspects that will make this problem more reactive on solar aspects. Expect dry loose activity to increase as the cold temperatures continue to facet the surface snow.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 19th, 2022 4:00PM
