Avalanche Forecast

Issued: Apr 18th, 2018 4:25PM

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

jsmith, Avalanche Canada

Northwest Coastal.

Forecast new snow and strong winds are expected to create touchy storm slabs reactive to human triggers; especially in wind affected terrain.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

THURSDAY: Snow; accumulation 10-15 cm. Strong southwest wind. Alpine temperature -1. Freezing level 1000 m. THURSDAY NIGHT: Snow; accumulation 10-15 cm. Strong southwest wind. Freezing level 800 m. FRIDAY: Snow; accumulation 5-15 cm. Moderate to strong south wind. Alpine temperature -1. Freezing level 1000 m.SATURDAY: Cloudy with flurries. Light west wind. Alpine temperature -1. Freezing level 1000 m.

Avalanche Summary

No new avalanches were reported in this region on Tuesday. However, I would expect the incoming storm on Thursday to form fresh storm slabs reactive to human triggers; especially in wind affected terrain at treeline and above.

Snowpack Summary

The incoming snow and strong winds on Thursday will create touchy storm slabs at treeline and above.In the south of the region, two layers of surface hoar are buried early-March and mid-March are approximately 70-100 cm deep and most prominent on north to east aspects. Further north, these layers are around 40 cm deep.Below these March layers the mid-pack is generally well-settled and strong. However in the far north of the region there are weak sugary facets near the bottom of the snowpack.

Problems

Storm Slabs

New snow may bond poorly to an underlying crust. Watch for fresh storm slabs in leeward areas near ridge crests and convex features.

Use small slopes with low or no consequence to test the bond of the new snow.Watch for signs of instability such as whumphing, cracking, or recent natural avalanches.Use caution when transitioning into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Loose Wet

New snow below treeline may quickly become moist and increase the likelihood of loose wet avalanches.

Watch for signs that the snow is heating up such as pin-wheeling or the surface snow becoming moist.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 19th, 2018 2:00PM