Avalanche Forecast

Issued: Jan 19th, 2013 9:31AM

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

Sea To Sky.

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

Loose wet avalanches to size 1 have been reported in steep, sun-exposed terrain.

Snowpack Summary

Above freezing temperatures 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-affected with continued surface hoar growth at lower elevations. 40-80 cm below the surface is a persistent weakness of surface hoar that was buried at the beginning of January. Recent tests have shown moderate results at this interface with resistent planar fracture characteristics. Although not widespread, this layer seems to be found in portions of sheltered terrain near treeline, and may still be fairly well preserved. 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 unsupported, shallow, rocky terrain where more facetting has taken place.

Problems

Loose Wet

Ongoing loose wet activity is possible with forecast 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 be possible in isolated unsupported terrain.

Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

Warm temperatures and solar radiation may increase the probability of avalanches releasing on a layer of surface hoar down 40-70 cm.

Conditions have improved, but be mindful that persistent instabilities are still present.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

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