Archived

Avalanche Forecast

Apr 19th, 2017–Apr 20th, 2017

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

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

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

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 Coast.

The main concern is storm slabs at higher elevations in the north of the region (Sky Pilot area). If you see more than 25cm of fresh snow, stick to simple terrain with low consequence and no overhead hazard.

Confidence

Low - Intensity of incoming weather systems is uncertain on Thursday

Weather Forecast

There is disagreement amongst weather forecasts for precipitation amounts on Wednesday through to Thursday afternoon. Thankfully, all forecasts call for fine weather on Friday.THURSDAY: Snow overnight Wednesday and then tapering by noon Thursday (accumulations of 20-30cm possible in the alpine). Freezing level 1500m. Winds moderate to strong southerly.FRIDAY: Sunny with cloudy periods. Freezing level rising to 2200m. High temperatures to +9 Celsius. Winds light southerly.SATURDAY: Wet weather returns around noon (10-20mm by the evening). Freezing levels falling to 1700m. Winds moderate southerly.

Avalanche Summary

No new avalanches reported, but there have been limited observations lately.Please enter your observations on the Mountain Information Network (MIN). See here for details.

Snowpack Summary

On Monday into Tuesday we had 40mm of precipitation in the North Shore Mountains, most of which fell as rain to the summits. In the Sky Pilot area, 20-30cm of snow likely fell above 1600m, forming storm slabs in the process. On Tuesday, an additional 10cm of snow may have fallen in the alpine.Southerly aspects at treeline and below contain moist snow that typically has not been refreezing overnight: Loose wet avalanches remain a concern in this elevation band.Cornices remain large in some areas and could trigger large avalanches when they fail (especially when warmed by the sun, or drenched by rain). Additionally, cornices present a falling hazard and should be given a wide berth while traveling on ridgetops.

Avalanche Problems

Storm Slabs

Significant snowfall amounts may accumulate in the alpine (near Sky Pilot) if freezing levels are low enough and strong winds are blowing.

Minimize exposure during periods of heavy loading from new snow and wind.Storm snow totals greater than 30cm are a red flag: Avoid avalanche terrain in such a case.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Likely

Expected Size: 1 - 3

Cornices

Where cornices exist, they are unstable and should be avoided.

Falling cornices can trigger large avalanches.Give cornices a wide berth when travelling on or below ridges.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3

Loose Wet

With the incoming rainfall at lower elevations and continued warm temperatures, there is an increased risk of loose wet avalanches. Even small slides can have serious consequences.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2