Avalanche Forecast

Issued: Nov 18th, 2017 8:17AM

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

ian gale, Parks Canada

Glacier.

Avalanche hazard is increasing.Avalanches now have the potential to run to valley bottom in places like Connaught Creek.

Summary

Weather Forecast

We're in for a stormy weekend! Today 5 cms are forecast, with 25km/hr winds from the Southwest gusting up to 50. Tonight we can expect 7cms of new snow and 25cm on Sunday. Further out the current forecast shows clearing Monday then another weather system Wednesday/Thursday bringing precipitation and high freezing levels

Snowpack Summary

Over of 50 cm of new snow has fallen in the last 48hrs. The snow pack has almost doubled in the last week and a half! The Halloween crust is the prominent layer we're watching and it's down approx 70cm. The November 9th is a hard to find & spotty surface hoar layer that might be found in the top 70cm.The snowpack remains shallow below 1700m

Avalanche Summary

Numerous avalanches to size 2 were observed yesterday in the highway corridor from very steep terrain on Mt MacDonald and Tupper. There was also avalanche debris reported from steep north facing terrain in Cannaught creek drainage. This increase in avalanche activity can be attributed to recent snow loading and strong winds in the alpine.

Confidence

Forecast snowfall amounts are uncertain

Problems

Storm Slabs

Heavy snow loading and strong alpine winds have created a reactive storm slab in the alpine. This storm slab will need a few days to bond to old snow surfaces. This problem will persist through the weekend.

Minimize overhead exposure during periods of heavy loading from new snow, wind.The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

The Halloween Crust layer is buried down approximately 70 cms, with the recent loading from heavy snow and strong winds we could see this layer become reactive. If it does the resulting avalanches would be large!

Minimize exposure during periods of heavy loading from new snow and wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Nov 19th, 2017 8:00AM