Avalanche Forecast

Issued: Apr 20th, 2018 3:39PM

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

jsmith, Avalanche Canada

Northwest Coastal.

25-30 cm of new snow has formed touchy storm slabs reactive to human triggers; especially in wind affected terrain.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

FRIDAY NIGHT: Snow; accumulation 5-10 cm. Strong south wind. Freezing level 800 m. SATURDAY: Cloudy with flurries; accumulation 3-5 cm. Moderate southwest wind. Alpine temperature -2. Freezing level 1000 m. SUNDAY: Cloudy. Light southwest wind. Alpine temperature 0. Freezing level 1300 m. MONDAY: Cloudy with isolated flurries. Light to moderate southwest wind. Alpine temperature +3. Freezing level 1800 m.

Avalanche Summary

No new avalanches were reported in this region on Thursday. However, I would expect the 20-30 cm of new snow to have formed fresh storm slabs reactive to human triggers; especially in wind affected terrain at treeline and above. Avalanche reports have been limited due to very few information sources this time of year. If you have been out, please post your observations on the Mountain Information Network. (MIN)

Snowpack Summary

20-30 cm of new snow and moderate winds have formed touchy storm slabs.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

25-30 cm of new snow has formed touchy storm slabs reactive to human triggers; especially in wind affected terrain.

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: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

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

Likely

Expected Size

1 - 2

Valid until: Apr 21st, 2018 2:00PM