Avalanche Forecast

Issued: Jan 19th, 2013 9:37AM

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

jlammers, Avalanche Canada

South Coast.

Summary

Confidence

Good

Weather Forecast

The stationary ridge of high pressure is expected to bring continued dry conditions to the region for the forecast period. Alpine temperatures are forecast to be about 3.0` for Sunday and Monday, and then dropping on Tuesday. Winds should remain mainly light from the west.

Avalanche Summary

Recent observations mostly involve snowballing and several wet loose sluffs up to Size 2 on sun-exposed slopes. A few wind slabs were observed to size 2 in the north of the region. They were formed by strong west winds a few days ago and have most likely gained some strength.

Snowpack Summary

Above freezing temperatures at higher elevations have caused snow surfaces to moisten on sun-exposed slopes; however, a nightly crust recovery is likely with forecast clear skies. The surface snow on northerly aspects is dry and wind-pressed with continued surface hoar growth at lower elevations. Below this, 40-80 cm of settling storm snow sits on a persistent weakness of buried surface hoar, facetted snow, and /or a crust. Recent snowpack tests show that this interface is gaining strength but may still be susceptible to human triggering . No significant weaknesses have been reported recently below this in the mid snowpack layers. Near the base of the snowpack, a crust/facet layer exists, which is now unlikely to be triggered, except perhaps by warming or heavy triggers in steep, shallow, rocky terrain where more facetting has taken place.

Problems

Loose Wet

Loose wet activity is expected with ongoing warm temperatures. Watch for triggering in steep, sun-exposed terrain.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

Strong variable winds have produced wind slabs in exposed lee and cross-loaded terrain. Although they've gained strength, human triggering may still be possible in unsupported terrain.

Stay off recent wind loaded areas until the slope has had a chance to stabilize.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Persistent Slabs

A buried weakness, down 40-80 cm, may become more reactive as a result of daytime warming. Watch for triggering on unsupported terrain.

Conditions are greatly improved, but be mindful that deep instabilities are still present.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Jan 20th, 2013 2:00PM