Avalanche Forecast

Issued: Jan 20th, 2014 9:00AM

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

ghelgeson, Avalanche Canada

Sea To Sky.

Summary

Confidence

Good

Weather Forecast

Synopsis: The proud upper ridge remains in place. Get used to it as its not going to make its exodus anytime soon.Tuesday: Freezing Level: 2700m; Precip: Nil; Wind: Light, SWWednesday: Freezing Level: 1300m; Precip: Trace; Wind: Mod, NWThursday: Freezing Level: 2500m; Precip: Nil; Wind: Light, NE

Avalanche Summary

No significant new observations over the weekend.

Snowpack Summary

Unseasonably warm daytime temperatures have left the snow surface in rough shape. A crust can be found on steep solar aspects to ridge top and on all aspects below 1600m. The crust may moisten when the air is still and the skies are clear. Previous winds have scoured windward slopes and sculpted sastrugi (raised ridges of snow) in exposed areas. Average treeline snowpack depths are around 170 cm. Initially, the bond below the most recent storm snow was reported to be weak and comprised surface hoar, at least in some locations. Recent snowpack tests indicate that this layer has gained strength and it is difficult to find a shear within the top 100 cm of the snowpack.There are two lower layers that professionals area tracking near the base of the snowpack. A facet/crust combo from late November is still giving "sudden" results in compression tests and exists at treeline and alpine elevations. Facets likely still exist at the base of the snowpack, especially in areas where the snowpack was particularly shallow early on in the season. The most likely places you would find this problem is in the alpine in shallow rocky areas.

Problems

Loose Wet

I suspect that the snowpack has largely adjusted to the warm temperatures. Regardless, it's prudent to adjust travel plans to avoid sun drenched slopes in the afternoon.

Cornices become weak with daytime heating. >Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

The affect of warm alpine temps will likely diminish in the coming days, but intense direct sun could destabilize the snowpack, especially on southerly aspects.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

4 - 7

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