Avalanche Forecast

Issued: Dec 7th, 2014 8:27AM

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

rbuhler, Avalanche Canada

Cariboos.

Watch for signs of changing stability as the temperature rises during the day.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

A warm, wet storm system will reach the coast early Monday. The Cariboos should remain dry for Monday and a mix of sun and cloud is expected. Temperatures will rise rapidly on Monday with the freezing level reaching 1500-2000m and winds increasing to moderate in the alpine. On Tuesday, the Cariboos will begin to see precipitation (3-6mm) and the freezing level is expected to be around 2000m. Wednesday is expected to be similar with freezing levels around 2000m and precipitation. Amounts are uncertain for Tuesday night and Wednesday with models currently showing 10-30mm. Strong alpine winds from the SW are expected for both Tuesday and Wednesday.

Avalanche Summary

The storm snow is reactive to ski cutting and is producing isolated avalanches up to size 1. I expect wind loaded areas in the alpine to be the main concern at the moment.

Snowpack Summary

Around 15cm of new snow sits on a weak layer of surface hoar. Reports from the region suggest that anywhere from 50-150 cm of settling snow overlies one or more weak layers which formed during November. Snowpack tests suggest that these weak layers are getting harder to trigger but still have the potential to produce large avalanches if triggered. Recent wind has created wind slabs in lee features in exposed alpine terrain.

Problems

Storm Slabs

We are at the early stages of a storm slab problem. Wind loaded features are the main concern at the moment. As we add warming and new precipitation to the equation, this problem is expected to become more widespread.

Use caution in lee areas in the alpine. Recent wind loading have created wind slabs.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The chances of triggering a persistent slab have decreased, but the consequences are still high. Any slopes that did not avalanche during the last storm cycle should still be considered potentially hazardous.

Choose well supported terrain without convexities.>Avoid common trigger zones including thin snowpack areas, near rocky outcrops, and steep alpine slopes.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Dec 8th, 2014 2:00PM