Archived

Avalanche Forecast

Apr 18th, 2019–Apr 19th, 2019

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

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: Sea To Sky.

Expect to find rapidly changing conditions with elevation, particularly as you transition through the rain-snow line. Travel conservatively to avoid wind slabs and loose wet avalanches.

Confidence

Moderate - Freezing levels are uncertain

Weather Forecast

THURSDAY NIGHT: Cloudy with rain switching to snow, accumulation 10 to 20 mm rain followed by 5 to 15 cm of snow, moderate to strong southwest wind, alpine temperature 0 C, freezing level 2400 m dropping to 1600 m.

FRIDAY: Cloudy with isolated flurries and afternoon clearing, accumulation 2 to 5 cm, light to moderate west wind, alpine temperature -3 C, freezing level 1700 m.

SATURDAY: Clear skies, light north wind, alpine temperature -2 C, freezing level 2000 m.

SUNDAY: Mix of sun and clouds, light southwest wind, alpine temperature -2 C, freezing level 2000 m.

Avalanche Summary

A few small natural avalanches were observed on Wednesday. Avalanche activity should be elevated Thursday into Friday as the storm pummels the Coast Mountains.

Snowpack Summary

Around 20 to 30 cm of snow likely accumulated above 2000 to 2400 m on Thursday into Thursday night. The snow fell with strong southwest wind, forming new slabs in the alpine. A freezing level decrease Friday night should drop another 5 to 10 cm of snow down to 1500 m by Friday morning. Below the rain-snow line, the snowpack is saturated and rapidly melting.

Avalanche Problems

Wind Slabs

Above the rain-snow line, around 20 to 30 cm of snow is expected to accumulate by Friday morning, with associated strong south to southwest wind. This new snow will likely remain touchy on Friday, particularly in lee terrain features.

Be careful with wind-loaded pockets, especially near ridge crests.
Expect conditions to change rapidly with aspect and elevation.
Use small slopes without consequence to test the bond of the new snow.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2.5

Loose Wet

Clearing on Friday afternoon could cause the new snow to moisten on sun-exposed slopes, forming loose wet avalanches.

Avoid terrain traps such as cliffs and gullies that increase the consequence of small avalanches.
Minimize overhead exposure and avoid steep slopes during periods of strong sun.

Aspects: East, South East, South, South West, West.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2