- Date Issued
- Friday, April 7, 2023 at 23:00
- Valid Until
- Saturday, April 8, 2023 at 23:00
- Prepared by
Terrain and Travel Advice
- Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Carefully evaluate bigger terrain features on an individual basis before committing to them.
Avalanche Problem 1: Deep Persistent Slab
The base of the snowpack remains very weak. Avoid thin, rocky start zones and shallow areas with variable snowpack depths.
Deep persistent slab avalanches continue to be reported in this forecast area. See the avalanche summary for details of a deep persistent slab avalanche that were kindly shared by some backcountry users who had a close call.
This is a low-probability/high-consequence avalanche problem, and managing it is very tricky.
Avalanche Problem 2: Storm Slab
The western slopes of the Purcells (the Bugaboos, Jumbo Pass etc.) are forecasted to get more snow than the rest of the region. In areas that get 15 cm of new snow or more, you could find pockets of storm slab that will avalanche under the weight of a rider.
On Thursday, north of Golden, just outside of the forecast area, a large (size 2), rider triggered, deep persistent slab avalanche was reported on a northwest aspect in the alpine. The avalanche started 50 m above the riders, and 2 sympathetic avalanches were observed on the adjacent slope. See the excellent Mountain Information Network (MIN) post here for more information, including photos, and reflections on a close call.
On Wednesday, west of Panorama, a large (size 2.5), naturally triggered wind slab avalanche was reported. It occurred on a Northeast aspect in the alpine during a stormy period.
Dry, powder snow remains on shaded (northerly) slopes. Moist snow or thin crusts exist on solar aspects at all elevations.
The mid-snowpack may still contain a number of weak layers, primarily in sheltered treeline terrain. However, no recent avalanche activity has occurred on these layers suggesting they are likely not a primary concern.
The lower snowpack includes a widespread layer of large, weak facets and/or depth hoar crystals. This weak layer has been responsible for several very large and destructive avalanches throughout the season, including one on Thursday.
Partly cloudy, fully cloudy on the west side of the Purcells. Trace of snow expected. 5-15 cm on the west side of the Purcells. Light southwest ridgetop wind, trending to moderate at higher elevations. Freezing level 1500-1750 m. Treeline temperature around -2°C.
Mostly cloudy, fully cloudy on the west side of the Purcells. Trace of snow expected. 5 cm possible on the west side of the Purcells. Light southwest ridgetop wind, trending to strong at higher elevations. Freezing level 1750 m. Treeline temperature around -2°C.
Cloudy on the west slopes and around Golden, mostly sunny on the east slopes. 0-5 cm of snow expected. Rain below 2000 m. Light southwest ridgetop wind, trending to strong at higher elevations.
Cloudy. 5-10 cm of snow expected in the alpine. Rain below 1900 m. Possible 25-35 cm on the west slopes of the Purcells. Light southwest ridgetop wind, trending to strong at higher elevations.
More details can be found in the Mountain Weather Forecast.
- Uncertainty is due to the fact that deep persistent slabs are particularly difficult to forecast.