Northwest Coastal

Forecast 25-35 cm of snow and strong southwesterly wind are expected to form reactive storm slabs.

Large, naturally triggered storm slab avalanches are likely on Wednesday.

Travel in avalanche terrain is not recommended.

A size 2.5 cornice fall was reported on a northerly aspect in the alpine on Monday. Additionally, a naturally triggered size 2 wind slab was observed on a northeast aspect in the alpine.

A fatal avalanche occurred north of Stewart on April 11th. It was a skier-triggered size 3 persistent slab avalanche that occurred on a northeast aspect in the alpine.

Most professional operations are now closed which means we have very little snowpack or avalanche observation data. Please consider sharing any information or photos you have on the Mountain Information Network to help guide our forecasts.

Forecast 25-35 cm of snow and strong southwesterly wind are expected to form fresh storm slabs reactive to human triggers.

A crust exists up to ridgetop on south-facing slopes and on all aspects up to approximately 1300 m.

The primary concern is two buried weak layers down 40-140 cm deep in most areas. They include facets and surface hoar in shaded areas and a melt-freeze crust elsewhere. Numerous human-triggered persistent slab avalanches have occurred on these layers during the past week.

The mid and lower snowpack is considered generally strong and well-bonded. In the far northern reaches of the region, basal facets may exist which are currently considered inactive. This layer may become active with abrupt changes to the snowpack, such as rapid loading (heavy snowfall or rain) or prolonged warming.

Tuesday Night

Snow; 15-30 cm / 60 km/h south ridgetop wind / Temperature at treeline around -3 C / Freezing level 1000 m

Wednesday

Snow ending mid-morning, then mostly cloudy; 10-15 cm / 50 km/h southwest ridgetop wind / Temperature at treeline around -3 C / Freezing level 1000 m

Thursday

Mix of sun and cloud / 40 km/h southwest ridgetop wind / Temperature at treeline around -1 C / Freezing level 1200 m

Friday

Sunny / 10 km/h west ridgetop wind / Temperature at treeline around 10 C / Freezing level rapidly rising to 3200 m!

More details can be found in the Mountain Weather Forecast.

• Only the most simple non-avalanche terrain free of overhead hazard is appropriate at this time.
• Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
• Use small low consequence slopes to test the bond of the new snow.
• Storm slabs in motion may step down to deeply buried weak layers resulting in very large avalanches.
• Back off slopes as the surface becomes moist or wet with rising temperatures.