Archived

Avalanche Forecast

Mar 18th, 2015–Mar 19th, 2015

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

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

Regions: Northwest Inland.

Forecast snowfall amounts are uncertain. Pay close attention to how much snow falls in your area, and choose terrain accordingly.

Confidence

Fair - Intensity of incoming weather systems is uncertain on Thursday

Weather Forecast

A pacific storm will intensify on Wednesday night bringing snowfall to the region for Thursday and Friday. A clearing trend is forecast for Saturday. Up to 15cm of snow is forecast for Wednesday night and Thursday. Around 5cm of snow is expected on Friday. Only light flurries are forecast for Saturday. Ridgetop winds should remain strong to extreme from the southwest. Freezing levels are expected to hover between 1200m and 1500m with Friday being the warmest day.

Avalanche Summary

On Monday, a skier triggered a size 2 wind slab on a NE aspect at 1300 m. Several loose avalanches also failed on steep sunny slopes. Click on the blue dot on the map to see a recent wind slab that may have failed naturally or remotely in Sinclair. It was a thick, hard wind slab on a north aspect. There are likely to more like this lurking. New snow and wind on Thursday will likely promote further wind slab activity.

Snowpack Summary

Anywhere from 20 to 120 cm recent storm snow has been redistributed by winds into soft and hard wind slabs at alpine and treeline elevations (highest storm snow amounts were in the north and west). This overlies various surfaces including old wind slabs, hard crusts, surface hoar, and/or surface facets. New snow and wind on Thursday is forecast to form new wind slabs in exposed lee terrain.At the base of the snowpack, weak facets may be found. Cornices are large and potentially fragile. Below treeline, the snow appears to be in a spring melt-freeze cycle.

Avalanche Problems

Wind Slabs

Forecast wind and snow is expected to form fresh and reactive wind slabs. Watch for triggering in gullies and in the lee of ridge crests.

Travel on ridgetops to avoid wind slabs on slopes below.>Give cornices a wide berth when travelling on or below ridges.>Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 4