Archived

Avalanche Forecast

Dec 31st, 2015–Jan 1st, 2016

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

1: Low

The avalanche danger rating in the alpine will be low

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: South Rockies.

There's a lot of uncertainty around what affect warming alpine temperatures will have. Widespread cornice failure and loose snow avalanches are likely, wind slabs may become more sensitive to triggering too. A cautious approach will serve you well.

Confidence

Low - Freezing levels are uncertain

Weather Forecast

The recent stormy pattern that December begat is history, and we enter a new meteorological regime marked by remarkable stability and a strong temperature inversion with an almost complete void of storminess over B.C for the next week. FRIDAY: No precipitation, freezing level at valley bottom with above freezing temperatures between 1600 and 2900 m, light SW winds. SATURDAY: No precipitation, freezing level at valley bottom with above freezing temperatures between 1500 and 2800 m, light SE winds. SUNDAY: No precipitation, freezing level at valley bottom, light S/SW winds. For a more detailed look at mountain weather visit avalanche.ca/weather

Avalanche Summary

On Wednesday control work produced a size 2 storm slab on a high elevation east facing feature. Previous to this, the last reported avalanche activity was on Sunday when a group of sledders triggered or remotely triggered a slab avalanche size 2.0 about 2 km south of Castle Mountain that resulted in one rider deploying his airbag and being partially buried. More details here: https://bit.ly/1TqhuQf

Snowpack Summary

As our field team travels around the region they are seeing very little wind effect. There is around 110 - 150 cm of snow on the ground at 2250 metres. The upper snowpack consists of about 40 cm of loose dry snow above 10 cm of cold facets that have been producing variable moderate to hard shears in snowpack tests. The storm snow is unconsolidated and earlier in the week the field team remarked that even the small larch trees still had new snow on them; continued evidence of very little in the way of wind. There may be more wind effect at higher elevations. These observations are consistent with reports from near Castle Mountain with storm snow above facets.

Avalanche Problems

Wind Slabs

Pockets of wind slab may not be well bonded to the old surface. Forecast warming may increase the sensitivity of wind slabs to triggering.

Use ridges or ribs to avoid pockets of wind loaded snow.>Avoid travelling in areas that have been reverse loaded by winds.>Avoid freshly wind loaded features.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Loose Wet

Loose moist or wet snow may release naturally on solar aspects or be easily triggered by light loads. Warming temperatures may cause cornices to fail naturally too.

Extra caution needed around cornices with current conditions.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Be alert to conditions that change with elevation, time of day and aspect.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2