Avalanche Forecast

Issued: Dec 14th, 2020 8:06AM

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

jonas hoke,

Sluffing continues to be a concern in steep unskied terrain Today.

Expect the hazard to increase steadily Tuesday and Wednesday with the incoming weather system.

Summary

Weather Forecast

Light snow and overcast today. A system hitting the central Coast will push a series of fronts inland, giving intensifying snowfall early Tuesday morning with up to 15cm by end of day Tuesday and 30cm by Wednesday. Wind will pick up on Tuesday afternoon to strong from the W, and alpine temps will rise to a high of -6 C by Tuesday afternoon.

Snowpack Summary

Traces of new snow and surface facetting continue to make for fast sluffing in steep terrain. Last weeks storm(30cm) buried a variety of surfaces; surface hoar up to 10mm (rounding in some areas); a thin crust from freezing rain in and around Connaught creek: and a stronger crust on steeper solar aspects. The Nov 5 crust is down between 1m and 1.5

Avalanche Summary

Skier triggered sluffing in steep terrain yesterday was significant enough to be of concern above cliffs and around terrain traps.

There was a MIN report of a skier triggered small avalanche in the alpine on Friday.

Several small-large solar triggered loose dry avalanches were observed late last week in the highway corridor from N and S aspects.

Confidence

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

Problems

Loose Dry

An icon showing Loose Dry

Cold temperatures and relatively light winds in most of the park have left unconsolidated snow with enough mass to push skiers and riders around in steep terrain. Extra care is required around cliffs and confined gullies.

  • Avoid travelling on ledges and cliffs where sluffing may have severe consequences.
  • Be aware of party members below you that may be exposed to your sluffs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A 30cm slab sits on the Dec 7th weak interface of rain crust/sun crust/surface hoar combo. Recent slab avalanches have failed on this layer. This layer could be more reactive in isolated terrain features that experienced more wind

  • Persistent slabs may be more sensitive to human triggering on solar asp where it sits on sun crust
  • Caution on open slopes and convex rolls at treeline and below, buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 2.5

Storm Slabs

An icon showing Storm Slabs

Storm slabs will begin to form Tuesday with snowfall and strong westerly winds.

  • The new snow will require several days to settle and stabilize.
  • Minimize exposure during periods of heavy loading from new snow and wind.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 15th, 2020 8:00AM