Avalanche Forecast

Issued: Nov 18th, 2012 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

A strong wet storm is headed onshore and looks like it will bring us moderate and possibly heavy snowfall depending on the exact track. This could create the first major avalanche cycle of the season. JBW

Summary

Weather Forecast

A strong southwesterly flow with a strong supporting jet will bring heavy precipitation to the southern Rockies. We may see as much as 20-30cm of snow. Winds will be very strong from the south west.

Snowpack Summary

First wave in a series of storms brought some light snowfall. Nov 6 crust is down 30. Windslabs in open areas. Expect up to 30 cm new by Tuesday.

Avalanche Summary

No new avalanches reoprted. Expect increase in avalanche activity within 24 hrs with new snow and wind.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Monday

Problems

Wind Slabs

Strong winds have begun to move snow creating some new slabs. If the strong storm coming onshore reaches us with the forecasted snowfall amount, it will rapidly increase the danger.

Aspects: North, North East, East, South East, South.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

Deep slabs size 2-3 have been noted on isolated steep alpine slopes over the past week. Failure plane was at the bottom of the snow pack on firn or glacier ice. Additional load and wind may be enough to create more avalanches of this nature.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Nov 19th, 2012 4:00PM