Register for an account and never miss a forecast again!
RegisterRegister for an account and never miss a forecast again!
RegisterDec 22nd, 2019–Dec 23rd, 2019
Lizard-Flathead.
A huge amount of snow and rain has stressed the snowpack, and overloaded a weak crust deep in the snowpack.
Sunday Night: Cloudy with isolated flurries, trace accumulation. Alpine temperature -4 C. Moderate south wind with gusts to 50 km/hr. Freezing level 1100 m.
Monday: Scattered flurries, trace to 10 cm. Alpine temperature -4 C. Moderate southwest wind gusting to 55 km/hr. Freezing level 1200 m.
Tuesday: Mainly cloudy. Alpine temperature -8 C. Light southwest wind. Freezing level at valley bottom.
Wednesday: Mix of sun and cloud. Alpine temperature -10 C. Light west wind. Freezing level at valley bottom.
Snow accumulation over the weekend overloaded deeply buried weak layers. A natural storm slab avalanche cycle to size 3 occurred Saturday and Sunday following intense and heavy loading from snow/rain and wind.
Skiers and snowmobiles triggered large (size 2) avalanches on Saturday. Explosives triggered very large (size 3-3.5) avalanches Saturday and Sunday, these avalanches failed on a deep persistent layer with some avalanche crowns over 200 cm. A complex avalanche problem has developed, read the latest forecaster blog here.
Upwards of 60 cm of heavy snow has fallen since Dec 20. Snowfall at upper elevations covered a previously variable and wind-affected surface and produced reactive (and large) storm slab avalanches. Wind and additional flurries will add to slabs at higher elevations. Below 1500 m, rain saturated the snowpack.
Crust layers from November and October can be found 40-100 cm below the surface. The intense loading from new snow has overloaded these weak layers, producing very large (size 3) avalanches on Saturday and Sunday triggered by explosives.
Snowpack depths range between 60-130 cm at higher elevations and taper rapidly below treeline.