Avalanche Forecast

Issued: Mar 19th, 2019 4:24PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Loose Wet and Wet Slabs.

swerner, Avalanche Canada

South Coast Inland.

Persistent warm temperatures are penetrating and destabilizing the upper snowpack. Natural avalanche activity is possible especially on sun exposed slopes. Avoid travel under avalanche paths especially with looming cornices overhead.

Summary

Confidence

Moderate -

Weather Forecast

WEDNESDAY: A mix of sun and cloud with alpine temperatures near +9 degrees. Ridgetop winds light from the East and freezing levels above 3000 m.THURSDAY: Cloudy with sunny periods. Alpine temperatures +7 degrees with freezing levels 2600 m. Ridgetop winds light from the southwest. FRIDAY: Cloudy with isolated rain showers and some flurries at higher elevations. Alpine temperatures near +3 degrees and freezing levels dropping to 1700 m in the North and 2600 m in the South. Ridgetop winds moderate from the East.

Avalanche Summary

On Monday, a widespread natural loose wet avalanche cycle up to size 3 was reported in the Northern half of the region. These avalanches failed on solar aspects (East, South and West). In the South, numerous natural avalanches were reported up to size 1.Â As we enter a period of increased warming it's worth reminding ourselves that glide cracks are to be avoided at all times. They're incredibly unpredictable and when they fail, they often fail big. Glide avalanche concerns are especially important to consider in the Coquihalla area. A recent social media post from a professional in this part of the region does a great job of highlighting the issue. (Link here) A glide failed naturally on a southeast facing slope around 1000 m on Saturday.We suspect natural avalanche activity will continue with the sunny skies and warming temperatures throughout the forecast period.

Snowpack Summary

Snow surfaces are highly variable. On higher elevation northerly aspects (above 1900 m) you may find some dry, faceted snow. Some of this has been redistributed by southwesterly and northerly winds, potentially creating some unusual wind slabs. On solar aspects (East, South, West) moist snow exists creating melt-freeze conditions at higher elevations and mostly just melt conditions below treeline. The bigger questions are deeper in the snowpack. With little overnight re-freeze the warm temperatures will penetrate deeper and continue to destabilize the snowpack. Itâ€™s hard to say how many hot days and warm nights it will it take to wake up the more deeply buried weak layers that we haven't thought about in a long time. Currently, the snowpack is complex and with the continued warming and little overnight re-freeze natural avalanche activity remains possible.

Problems

Loose Wet

Loose wet activity is expected to continue on all aspects and elevations except north facing, alpine slopes. Cornices are softening up and weak. You don't want to be under or near one of these looming monsters when they fail.

Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.Cornices become weak with daytime heating or solar exposure.Loose avalanches may start small but they can gain mass and push you into dangerous terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Wet Slabs

As the warming penetrates deeper in the snowpack large wet slabs may fail naturally, especially where buried crust or facet interfaces exist. Avoid avalanche terrain, especially if its baking in the sun.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.Avoid exposure to overhead slopes with Glide Cracks. Avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1.5 - 2.5

Valid until: Mar 20th, 2019 2:00PM