Avalanche Forecast

Issued: Mar 26th, 2021 2:00AM

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

Ryan Shelly, VIAC

Vancouver Island.

No new avalanches observed.

Summary

Past Weather

Spring melt freeze cycle continues to exhibit its will onto the Vancouver Island snowpack creating a dense surface snowpack and some minimal wet sloughing on steep unsupported terrain. Friday: No snow expected throughout forecast area, Winds Moderate from the WNW, Freezing level 1,700MSaturday: Less than 2cm snow expected throughout forecast area, Winds Moderate from the WSW (gusting to moderate in afternoon), Freezing level 1,000M (except Freezing level rising to 1300M on Central Vancouver IslandSunday: Moderate to heavy Snowfall expected (Rain expected at Below Treeline Elevation band) 15cm snow to 35cm snow expected throughout forecast area at Treeline and Alpine, Winds Moderate from the WNW, Freezing level 1,050M

Weather Forecast

Expect the spring melt freeze cycle to take a pause on Sunday as Extreme winds, Moderate snowfall rates and lower freezing level bring a return to Powder Shots?! The last gasp of winter?!

Terrain Advice

Practice patience and allow time for new storm instabilities to stabilize prior to committing to any steep terrain.Plan routes and choose terrain that is low angle and supportive as you begin to venture into unmodified and uncontrolled snowpack and terrain.Identify and avoid travel either above or below cornice features.Adjust travel plans to ensure avoidance of slopes during warming and where rain events may occur.

Snowpack Summary

A firm yet moisture laden snowpack has formed and brought about a great deal of stability as the result of warm daytime heating and a nighttime cooling (well below zero).

Snowpack Details

Surface: Hard surface snowpack on Solar aspects and firm upper snowpack on Northerly terrain
Upper: A well bonded and dense moisture laden snowpack
Mid: A well bonded and dense moisture laden snowpack
Lower: A well bonded and dense moisture laden snowpack

Confidence

Moderate - Weather models in agreement. Limited weather and snowpack observations submitted from public.

Problems

Cornices

Very large cornices exist and continued snowfall, wind and high humidity continue to promote cornice growth. Cornice failures have the potential to over load the snowpack and trigger both new snow instabilities as well deeper instabilities. Expect the new growth to be fragile and when temperatures and freezing levels rise become suspected triggers in bigger avalanche events. Location: Many aspects at ridge top in the Alpine and Tree line. Possibility: Triggering of this avalanche problem is likely to very likely from light loads such as skiers/snowmobilers. Natural avalanches are possible to likely. Size: If triggered expect these avalanches to be large size 2, on isolated terrain features very large, size 3

Likelihood

Possible

Expected Size

1 - 1

Wind Slabs

Wind slabs could become a factor Sunday in areas where precipitation arrives in excess of 20cm coupled with Extreme winds and a lower freezing level. Found predominantly on downwind aspects, the location of the wind slab will most likely be found on North facing terrain. This avalanche problem overlies a variety of snow surfaces, mostly a wet upper snowpack surface or a firm melt freeze crust (depending on elevation and aspect). Location: Many aspects and found in both the Alpine and Tree line. Winds are shifting direction on Tuesday night into Wednesday which will contribute to reverse loading and essentially complicate terrain management due to availability of new light dry snow being relocated to many downwind aspects. Possibility: Triggering of this avalanche problem is possible to likely from light loads such as skiers/snowmobilers. Natural avalanches are unlikely to possible. Size: If triggered expect these avalanches to be size 1, on isolated terrain features very large, size 2 .

Likelihood

Possible

Expected Size

1 - 1

Storm Slabs

This new avalanche problem will develop in areas that receive snow in excess of 20cm- sensitivity to triggering will increase over the course of the storm event. On isolated Alpine terrain expect this new snow to overly a firm upper snowpack, on solar aspects, expect the storm snow to overlie a melt freeze crust. Location: All aspects, Alpine and Tree line. Below tree line hazard is from above. Possibility: Triggering of this avalanche problem is possible to likely from light loads such as skiers/snowmobilers. Natural avalanches are unlikely to possible. Size: If triggered expect these avalanches to be large size 1, on isolated terrain features large, size 2.

Likelihood

Possible

Expected Size

1 - 1

Valid until: Mar 27th, 2021 2:00AM