Avalanche Forecast
Issued: Apr 17th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Dry and Persistent Slabs.
snow safety,
An upslope storm will occur Sunday but snowfall amounts are uncertain. Watch for sloughing where new snow overlies a crust.
Summary
Weather Forecast
A NE flow will develop Saturday night bringing more snow to the East side of the Rockies. Expect anywhere from 5-15cm of snow throughout the day. Temperatures will start to drop in the AM with alpine temperatures going down to -15C, and valley bottom temperatures around 0C. This cooling will continue Monday, and start to warm up again on Tuesday.
Snowpack Summary
Surface crusts present on solar aspects and all aspects up to 2200 m in the morning, quickly turning to wet snow as the day warms up. High elevation north aspects still holding dry snow. Several persistent layers exist in the mid to lower snowpack from earlier in the winter that may become active layers again over the next 48 hr as things heat up.
Avalanche Summary
On Friday and Saturday explosive control on the 93 S and in Yoho produced good results up to size 3 with small slabs at treeline gouging into deeper layers at lower elevations and running full path. Widespread natural loose wet avalanche activity up to size 2 was also observed at all elevations.
Confidence
Problems
Loose Dry
Watch locally for snow amounts that occur Sunday. Where these overly crusts sloughing is a possibility if there is a poor bond, especially in gullies.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Cooler temperatures may decrease the likelihood of deeper layers in the mid to lower snowpack being triggered. If there is a poor freeze or one of the many large cornices fails, larger avalanches on these layers are still a possibility.
- Pockets of persistent slabs linger on alpine lee features.
- Pay attention to overhead hazards like cornices which could trigger persistent slabs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 18th, 2021 4:00PM
