Avalanche Forecast

Issued: Feb 15th, 2017 4:40PM

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

mgrist, Avalanche Canada

Sea To Sky.

We're into a period of HIGH danger with ongoing loading of the snowpack on Wednesday into Thursday: rain to treeline and heavy snow in the alpine.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

Warm and wet still on Thursday. Cooling with isolated flurries on Friday, and improving for Saturday.THURSDAY: Rain or wet snow (25-40 mm / cm) / Strong southerly winds in the afternoon / Freezing level around 1400 m. FRIDAY: Mostly cloudy with locally heavy flurries possible (5-15cm) / High temperatures to -1 Celsius / Light westerly winds / Freezing level around 1100 m. SATURDAY: Cloudy with sunny periods / Ridge winds light southerly / Freezing level around 900m / High temperatures to -2 Celsius.

Avalanche Summary

Several small loose wet avalanches were reported at treeline and below on Wednesday. Several natural storm slab avalanches to Size 2 were reported in the alpine on Wednesday.

Snowpack Summary

We had strong southerly winds and heavy rain to 1500m on Tuesday night (and rain to 2000m during the day Wednesday). This new rain (or snow higher up) sits on either wind slabs in the alpine or temperature crusts at treeline and below, especially on east and south aspects. Both of these surfaces will be good sliding layers for future snowfall. The mid and lower snowpack is generally well settled (strong). However, there remain a number of facet and crust layers (down 60-80cm in shallower areas) that are currently dormant but will require monitoring with additional loading (and warming this week), especially in the shallow, rocky areas.

Problems

Storm Slabs

Where precipitation falls as snow, watch out for storm slabs, especially on wind-loaded northerly features.

Avoid areas with overhead hazard.Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Loose Wet

Heavy rain at treeline and below will cause the snow to become soft and cohesionless. Avoid getting pushed into terrain features like gullies and cliffs, where even small slides could have large consequences.

Use extra caution on slopes if the snow is moist or wet.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Feb 16th, 2017 2:00PM