Avalanche Forecast
Issued: Dec 27th, 2019 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is
shorton,
Avalanche Canada
Triggering large deep persistent slab avalanches remains a concern. Travel with caution and avoid steep rocky terrain.
Summary
Confidence
Moderate - Uncertainty is due to the complexity of the snowpack’s structure.
Weather Forecast
FRIDAY NIGHT: Clear with cloudy periods, 30-50 km/h wind from the northwest, alpine temperatures drop to -15 C.
SATURDAY: Mix of sun and cloud, 30 km/h wind from the west, alpine high temperatures around -10 C.
SUNDAY: Cloudy with some light flurries and 2-8 cm of snow, light wind from the north, alpine high temperatures around -8 C.
MONDAY: Mix of sun and cloud, light wind from the northwest, alpine high temperatures around -8 C.
Avalanche Summary
Avalanche activity is on the decline following the intense storm and avalanche cycle last weekend. During the storm large (size 2) storm slab and very large (2.5-3) deep persistent avalanches occurred naturally. Most notable (and concerning) were reports of deep persistent slab avalanches with 40-200 cm thick crowns. Since then, several size 2 wind slab avalanches have been triggered with explosives and cornices.
While the likelihood of triggering a deep persistent slab avalanche is on the decline, there is still a fair bit of uncertainty about this problem, and the consequences of triggering a very large avalanche are severe.
Snowpack Summary
Upwards of 50-100 cm storm snow is settling around the region. At higher elevations, wind is blowing low density snow into wind slabs and cornices. At lower elevations rain saturated the snowpack up to 1600 m. The bottom 30-50 cm of the snowpack consists of weak facets and crusts, which were the failure plane for recent large (size 2-2.5) deep persistent slab avalanches. The latest forecaster blog discusses managing this complex avalanche problem (check it out here). Snowpack depths range between 80-200 cm around treeline and taper rapidly below.
Terrain and Travel
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Choose slopes that are well supported and have limited consequence.
- Conditions may have improved, but be mindful that deep instabilities are still present.
- Be carefull around freshly wind loaded features.
Valid until: Dec 28th, 2019 4:00PM
