Avalanche Forecast

Issued: Nov 25th, 2011 8:46AM

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

Avalanche Canada triley, Avalanche Canada

Summary

Confidence

Poor - Due to limited field observations

Weather Forecast

Moderate precipitation overnight Friday is forecast to become heavy to very heavy precipitation on Saturday morning as the next system lands on the north coast. The system should bring very strong winds with gusts above 100 km/hr. Friday evening and during the day on Saturday. Another disturbance is forecast to follow on Sunday night bringing continued moderate precipitation combined with moderate westerly winds. Freezing levels in the coastal mountains are forecast to rise to 1200 metres on Saturday and then drop back to about 700 metres on Sunday. The inland areas near Smithers are forecast to get less wind and snow as the system is aligned to travel southward along the coastal mountains.

Avalanche Summary

Very little natural activity reported given the amount of snow that has fallen in the past few days. Most reports are of size 1-1.5 along the highway corridor from steep isolated terrain features.

Snowpack Summary

Most areas received over a metre of new snow since the weekend, and it's still snowing. Fluctuating freezing levels and varying precipitation intensity and wind throughout the recent storms has probably resulted in various weaknesses within upper snowpack. Widespread large surface hoar was also observed on the previous snow surface at all elevations. The mid and lower snowpack is generally well settled and strong with an old rain crust near the ground.

Problems

Wind Slabs

An icon showing Wind Slabs
Weak wind slabs are probably lurking well below ridge crests, behind terrain breaks, and in cross-loaded gullies. Natural avalanche activity probably occurred and is expected to continue in response to heavy loading from snow and wind.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Storm Slabs

An icon showing Storm Slabs
Storm slabs are likely very touchy, especially where they are sitting on surface hoar.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Valid until: Nov 26th, 2011 8:00AM