Avalanche Forecast
Issued: Jan 1st, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Loose Dry.
mark herbison,
A juicy storm system will affect most of the forecast region, bringing snow and strong wind for the weekend.
Expect the avalanche hazard to rise throughout the day as the storm progresses.
Summary
Weather Forecast
Here we go! A storm system will track its way through the region starting Friday night through Sunday. Saturday will see snow accumulations of 10-20cm by the evening, strong to extreme winds from the SW and temps ranging from 0 to -8. By Sunday morning there is an additional 20-25cm forecasted accompanied by the continued strong to extreme winds.
Snowpack Summary
On Friday the surface snow was soft with isolated areas of wind effect in the alpine. The Dec 13 and Dec 7 sun crust/surface hoar/facet layers are down ~ 50cm and ~80 cm respectively and will be tested by the incoming snow load. The decomposing Nov crust/facets sits at the bottom of the snowpack. Height of snow at tree line is 120-180cm.
Avalanche Summary
As the storm intensifies Saturday and into Sunday, expect avalanche activity to increase. The additional snow load may wake up deeper layers, resulting in large avalanches.
No reports of natural or human triggered avalanches on Friday. Skier triggered sz 1.5 on Hector South area on Thursday.
Confidence
Problems
Storm Slabs
The accumulating snow has the potential to form storm slabs at all elevations, potentially overloading deeper layers in the snowpack. The strong SW winds will build wind slabs in the alpine and in open areas at tree line.
- If triggered the storm slabs may step down to deeper layers resulting in large avalanches.
- Use caution in lee areas in the alpine and treeline. Storm snow is forming reactive slabs.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Dry
This problem will progress as the snow continues to fall and will be an issue in steep, confined terrain features in the alpine and down below tree line.
- Be careful of loose dry power sluffing in steep terrain.
- If triggered dry loose point releases can form deeper deposits in terrain traps.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 2nd, 2021 4:00PM
