Avalanche Forecast

Issued: Nov 29th, 2015 7:56AM

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

bcorrigan, Avalanche Canada

Cariboos.

Rising temperatures in the alpine may change the snowpack dramatically, especially on solar aspects.A big THANK YOU! to riders sharing their observations with the Mountain Information Network. MIN

Summary

Confidence

Fair - Due to the number and quality of field observations

Weather Forecast

A ridge of high pressure continues to dominate the weather pattern over western Canada and is not forecast to move out of the area until Tuesday or Wednesday next week. In the meantime, an above-freezing layer (AFL) of air will pass through the region between 1500 and 3000m bringing temperatures in that elevation band to as high as +5c, especially on solar aspects. Arctic air pooling in the valley bottoms will keep the temperatures well below freezing until the next storm system flushes out the cold air.We can expect valley fog in the mornings, hopefully clearing out by the afternoon.

Avalanche Summary

No reports of avalanches in the Cariboo region from the last few days. If you have observed any, please share your information through the Mountain Information Network

Snowpack Summary

The snowpack is extremely variable at this time, with wind scoured North facing slopes at treeline and above. South facing slopes have wind slabs at tree line and above and may be hiding surface hoar from the previous spell of cold clear weather. Surface facetting has observed in the region as a result of the recent cold weather and clear skies, and surface hoar as large as 40mm has been reported building in sheltered locations below tree line! There are a number of surface hoar layers now buried in the snowpack that seem to be unreactive, with the most recent having been buried on Nov 24th. In shallow snowpack areas, especially on northern aspect, there is a weak facetted layer at the base of the snowpack. Warming temperatures and strong solar radiation has built a sun crust on solar aspects.

Problems

Loose Wet

Warm temperatures and solar input may create loose wet avalanche conditions on sun-drenched slopes

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

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Wind Slabs

Wind slabs on south slopes especially just below ridge tops may be triggered by skiers or sledders. The current warm temperatures at upper elevations will promote bonding of these wind slabs.

Be cautious as you transition into wind affected terrain.>Avoid travelling in areas that have been reverse loaded by winds.>Avoid freshly wind loaded features.>

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Deep Persistent Slabs

Facetted crystal have been reported in shallow snowpack areas on north aspects. A collapse of this layer could trigger a large destructive avalanche.

Be aware of thin areas that may propogate to deeper instabilites.>Now is a good time to dig a snow profile (or two) and figure out how the snowpack changes with aspect and elevation.>Avoid shallow snowpack areas where triggering is more likely.>

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

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

1 - 4

Valid until: Nov 30th, 2015 2:00PM