Avalanche Forecast

Issued: Mar 4th, 2020 1:00AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Persistent Slabs and Storm Slabs.

Bill Phipps, VIAC

Vancouver Island.

No new avalanche observations have been submitted since Sunday.

Summary

Past Weather

Small amounts of new moist snow have fallen since Sunday with accumulations around 2 to 4 cm. Temps have been mild (-4 to 0). Winds have been moderate from the SE to SW. Freezing levels 1100 to 400 m.

Weather Forecast

Here comes another hit of winter! No Juicy Fruit gum commercial spring skiing yet.... If you are too young to get this, is worth looking it up on Goggle... (greatest snow quantities in the west/Strathcona, then norths/Cain and least in the east/Washy) Wednesday- 5 to 16 cm of new snow, winds strong to moderate SW-SE, temps -4 to -8, freezing levels 500 to 800 m.Thursday- 18 to 46 cm of new snow, winds strong SE-SW with potential for some gusts to EXTREME SE, temps -3 to -6, freezing levels 400 to 1000 m.Friday- 5 to 20 cm of new snow, winds light SE-SW, temps -6 to -9, freezing levels 0 to 600 m.

Terrain Advice

Don't pull out the garden tools and golf clubs just yet. A large storm system arrives Tuesday night and brings significant snowfall into Wednesday. Avoid lee slopes (NW to NE) in the alpine and open treeline until this new snow has had time to bond and settle. There will be fun to be had below treeline, on less steep terrain and in the protected forest zones during this winter blast.

Snowpack Summary

Small amounts of moist new snow has fallen on the previous surfaces since Sunday with accumulations of 2- 4 cm.

Snowpack Details

Surface: Small amount of new snow (2-4 cm) over a thin sun crust on solars and on old snow on non solars.
Upper: 30 to 100 cm of settled storm snow with a few thin crusts sandwiched between on solar aspects.
Mid: a thick crust with weak snow crystals on top and some weak crystals forming below as the crust degrades
Lower: well settled

Confidence

High - Many days of field data and weather models in agreement

Problems

Persistent Slabs

Our weak crystal layer (facets and buried surface hoar) has been slowly settling and becoming less of a concern, however it still (though unlikely) has the potential to slide. It is now down anywhere from 35 to 100 cm and sits upon a decomposing crust. If this persistent slab layer were to be triggered it could produce an avalanche up to size 3. If we were to seek out its main location it would be at treeline on northern aspects. This layer maybe come more reactive with the substantial new snow and wind loading expected during this forecast period.

Likelihood

Possible

Expected Size

1 - 1

Storm Slabs

A big winter hit will bring significant new snowfall and strong winds during this forecast period. This new snow will certainly create storm slabs with the potential to avalanche up to size 2.5 in the alpine and open treeline. These slabs will very likely trigger with human activity and are likely to fail with natural causes. They will be on all aspects in the alpine and treeline especially NE to NW slopes, cross loaded features, gullies and open bowls. Sticking to the trees and low angled terrain will be your best bet to avoid this danger.

Likelihood

Possible

Expected Size

1 - 1

Valid until: Mar 5th, 2020 1:00AM