Avalanche Forecast

Issued: Jan 18th, 2014 9:06AM

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

ghelgeson, Avalanche Canada

South Coast.

Summary

Confidence

Fair

Weather Forecast

Synopsis: A strong upper ridge of high pressure will dominate the weather pattern for least a week.Sunday: Freezing Level: 1500m Precip: Nil Wind: Light, WestMonday: Freezing Level: 3000m Precip: Nil Wind: Light, SouthTuesday: Freezing Level: 3000m Precip: Nil Wind: Light, W/NW

Avalanche Summary

Natural avalanche activity involving the basal facets continued Friday. A few avalanches to size 2.5 were reported from the north of the region on gently inclined north facing slopes at upper elevation. On Thursday, a natural avalanche occurred on the SE face of Mt. Rohr, size 2.5, running to mid runout on basal facets. On Wednesday, explosive control in the North Cascades produced a couple size 2.5 on N and NE aspects. In the same area, there were also some loose wet avalanches below treeline up to size 1. In the Northern part of the region, there were also report of remotely triggering a couple size 2 avalanches which would have run on basal facets in the alpine on NE aspects.

Snowpack Summary

Very warm alpine temperatures have created a moist snow surface. Previous winds have scoured windward slopes and sculpted sastrugi in exposed areas. Initially, the bond below the most recent storm snow was weak. However, settlement due to the warm temperatures appears to have settled the upper snowpack and it has appeared to have gained strength.There are two lower layers of note near the base of the snowpack. A facet/crust combo from late November (down approximately 100-120 cm) is still giving "sudden" results in compression tests and exists at treeline and alpine elevations. Facets and depth hoar 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, and it has been most widely reported from the Duffey Lake and Chilcotin areas.

Problems

Deep Persistent Slabs

Heavy triggers such as a moist/wet avalanche or a cornice drop could step down to deeper instabilities.

Minimize exposure to overhead avalanche terrain, large avalanches may reach run out zones.>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 6

Loose Wet

Warm alpine temperatures could destabilize the snow surface on all aspects but especially on SE and S aspects. Loose avalanches could trigger larger slab avalanches.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Avoid exposure to sun exposed slopes.>

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Valid until: Jan 19th, 2014 2:00PM