Avalanche Forecast

Issued: Feb 20th, 2014 9:02AM

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

Avalanche Canada bcorrigan, Avalanche Canada

With the end of this last storm cycle we`ll be transitioning from storm slab to persistent slab for the major concern.See the latest Blog Post

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

The last of the Pacific fronts should have moved out of the area by mid day Friday, although there may be some small "squall" precipitation events before the area cools down and clears off. Cold weather in the forecast for early next week.Thursday night: Freezing level at valley bottom, light flurries with possibility of 5cm in the forecast. Winds at ridge top NW, gusting to 50 Km/h.Friday: Freezing at valley bottom, no precipitation in the forecast. Cool dry air moves into the region, ridge top winds, NW up to 40Km/h.Saturday: Freezing level at valley bottom no precipitation, sunny, ridge top winds from the north up to 20 Km/h.Sunday: Freezing level at valley bottom, Cold clear weather, ridge top winds around 30 Km/h.

Avalanche Summary

No recent reports of natural avalanches, but we are still hearing reports of whumpfing and wind loaded slopes cracking. Numerous skier remote (up to 50 m away) have been reported in the northern part of the region. I would be highly suspicious of wind loaded slopes at all elevations. Use conservative terrain choices and make observations as you travel.

Snowpack Summary

The region has received between 35-90 cm of new snow, with more snow to the western part of the region, tapering of as you travel further east, now overlying a variety of old surfaces.  These buried surfaces consist of weak surface facets, surface hoar (more predominant at tree line and below tree line elevations), a scoured crust, wind pressed snow, or any combination of these left over from earlier weather. Whumpfing, cracking, and reports from the field indicate a very poor bond between the new snow and these old surfaces. Reports from the Hankin area on a NE facing slope 1300m show an ice crust down 50cm with facets above and below. A compression test easy @ 25cm and another down @48cm, sudden collapse ( Thanks BH!) Strong winds and slight warming have added cohesion to the storm slab, and transported some of the new snow into deeper, and more destructive wind slabs on the lee side of ridge tops.The mid and lower snowpack are generally strong and well-settled. Basal facets and depth hoar are likely to exist in some parts of the region, but skier triggering has become unlikely. A wind slab avalanche could step down to these basal facets and produce a large destructive avalanche.

Problems

Storm Slabs

An icon showing Storm Slabs
Wind slabs and shallow snow pack areas should be on the radar now. It's not necessary to be on a big slope to trigger it, that could happen from a distance. Use careful route finding and cautious evaluation of the terrain where you plan to ride/ski.
Choose conservative lines and watch for clues of instability.>Avoid freshly wind loaded features.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Valid until: Feb 21st, 2014 2:00PM