Avalanche Forecast

Issued: Nov 23rd, 2014 7:55AM

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

Avalanche Canada triley, Avalanche Canada

Avalanche Danger is expected to increase as weather systems roll across the province and add to the developing storm slab. If new snow amounts are greater than 20 cm, consider these danger ratings to be too low.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

A fast moving Low pressure system is expected to move through the interior mountains overnight bringing moderate precipitation and strong Westerly winds. There should be a brief break between this storm and the next one that is forecast to move onto the West coast early Monday morning. The timing and trajectory of this next system are difficult, but it looks like it might get pushed down into the Southeast corner of the province by Monday night or Tuesday morning. Some of this moisture may still be lingering in the Southeast when a more southerly storm moves across the interior on Tuesday night or early Wednesday. Expect warm, wet and windy conditions on Tuesday, with a cooling trend into Wednesday.

Avalanche Summary

We have no reports of avalanches from this region. I suspect that recent storm slabs in the alpine may be easy to trigger where they are associated with a crust and/or facets. Storm slabs are expected to continue to develop with the forecast snow and wind.

Snowpack Summary

As we begin our forecasting season we are working with very limited field data. If you have been out in the mountains, please send us a note with your observations to forecaster@avalanche.ca.The limited field data that we have received suggests that there is not enough snow at and below treeline for avalanche activity. If this is not the case in your area, then you may want to consider the avalanche danger to be similar to the Alpine. The storm slab in the alpine may be sitting on a weak layer of facetted snow, surface hoar, and/or a wind or sun crust that developed earlier in the month. This storm slab has been touchy to human triggers, and is expected to continue to develop with the forecast snow and wind.We are interested in snow depths at different elevations ( alpine, treeline, below treeline), spatial extent of the crust/facet weak layer, and new snow/ storm snow amounts. Avalanche danger may rise quickly if new snow amounts are greater than 20 cm per day.

Problems

Storm Slabs

An icon showing Storm Slabs
Storm slabs are expected to continue to develop as a series of storms keep rolling through from the coast over the next few days. If temperatures cool a couple of degrees, this problem may develop at lower elevations.
Be cautious as you transition into wind affected terrain.>The new snow will requires several days to settle and stabilize.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Nov 24th, 2014 2:00PM