Avalanche Forecast Sea to Sky

Date Issued: Valid Until:

Avalanche Canada jsmith, Avalanche Canada

Avalanche Forecast

Fri Apr. 12th ยท 4:29PM

Alpine

Danger Ratings Considerable

Treeline

Danger Ratings Considerable

Below Treeline

Danger Ratings Moderate
Storm Slabs Storm Slabs

Alpine

Danger Ratings Considerable

Treeline

Danger Ratings Considerable

Below Treeline

Danger Ratings Moderate

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Moderate
A brief return to winter! 10-20cm of new snow, strong winds, and low freezing levels are forecast to create fresh storm slabs reactive to human triggers by the end of day Saturday. Hazard may be lower in areas that receive less than 15 cm of snow.

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

FRIDAY NIGHT: Increasing cloudiness / Moderate, southwesterly winds / Alpine low -2 C / Freezing level 1000 m.SATURDAY: Snow; 10-20 cm. (rain below roughly 1000 m.) / Strong, southwesterly winds / Alpine high -1 C / Freezing level 1200 m.SUNDAY: Mostly cloudy / Light, southwesterly winds / Alpine high -1 C / Freezing level 1100 m.MONDAY: Mostly cloudy / Light, southwesterly winds / Alpine high 0 C / Freezing level 1300 m.

Avalanche Summary

On Thursday, there were numerous small (size 1) skier triggered storm slabs reported on primarily northerly aspects below ridgetops near Whistler. Avalanche activity is expected to increase on Saturday with the forecast snow and wind.On Monday, four skier-triggered storm slab avalanches (size 1.5-2) in the Whistler backcountry were reported on north facing aspects below alpine ridgetops, including this Decker Main MIN report here.

Snowpack Summary

Currently, the snowpack structure changes dramatically with elevation and aspect. 15-30 cm. of recent storm snow (amounts tapering with elevation) is sitting on a melt/freeze crust, except for north facing terrain above 2000 m. where the old snow surface remained dry and small surface hoar (weak, feathery crystals) may be present in isolated locations. This recent snow has been affected by the sun and re-distributed by southerly winds, forming wind slabs on lee features below ridgetops.Below roughly 1900 m, the snowpack is moist and is melting rapidly at lower elevations. Check out this useful link for managing avalanche hazard during spring conditions HERE.

Problems

Storm Slabs

Storm Slabs

10-20 cm of new snow, strong winds, and low freezing levels are forecast to create fresh storm slabs reactive to human triggers by the end of day Saturday.

Minimize overhead exposure during periods of heavy loading from new snow and wind.Pay attention to changing conditions with elevation/aspect.Use small slopes without consequence to test the bond of the new snow.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2