maxwell
Active VIP Member
just wanted to show you guys what taking ten minutes to read the avy bulletins can avoid. i found it amazing how well this forcast basically predicted this avalanche on sunday. this is the posted bulletin from sunday and i highlighted the areas that directly relate to this particular slide. the topic of the day is wind slabs and loading. take a look at the top left corner of this bad boy. also look at the very center of the crown where it broke and how there is a rock and about 6 inches of snow. then read the bulletin. take the highlighted information and it pretty much describes exactly what happened here. this information is free!:d:d and im in no way bashing the guy that set this off. i just find it very interesting.
New soft wind slab from higher than forecast Northeast winds. Older harder wind slabs below ridge crests, behind terrain features, and in cross-loaded gullies.
Various persistent weaknesses strewn throughout the snowpack, including facets at the base, create the potential for highly destructive avalanches running to valley bottoms. Cornice falls may be the trigger to release these very large avalanches
The dry light storm snow is sluffing in steep terrain on all aspects. In places where the winds have affected the surface, the sluffing may release the storm snow as a slab.Updated by T Riley
Special Message
Deep persistent slab avalanches are becoming less likely but the consequences remain extremely high. Diligence and discipline may be required to resist venturing into complex terrain even if there are no obvious signs of unstable snow. Pre-trip planning should involve talking to trained and experienced riders with local knowledge to determine if a weakness of concern has been removed by recent avalanche activity.
Confidence: Fair
The Northeast winds have been stronger than forecast.
Weather Forecast
Synopsis: Freezing levels remain at valley bottom with treeline temperatures around -10 to -15. Ridge top winds are light to moderate from the north-northeast. Expect little change until Wednesday evening.
Updated by T Riley
Avalanche Activity
A widespread natural avalanche cycle was reported in parts of the Cariboos on Wednesday, corresponding with new snow, warm temperatures, and strong winds. Avalanches were generally up to size 2 and involved only the new snow. Several skier triggered slab avalanches up to size 1.5 were also reported.
Very large avalanches remain possible. They are more likely in areas where the snowpack is (or was) shallow and faceted. These will generally require heavy triggers such as cornice falls, sled tracks digging deep, or smaller avalanches stepping-down.Travel Advisory
Areas to Avoid:
Common trigger points such as convexities or slopes with shallow snow cover where rocks or small trees are poking out.Convex shaped slopes or unsupported slopes where triggering an avalanche is more likely.
Be aware of what is above you. Avoid exposing yourself to overhead hazards like large complex slopes and overhanging cornices.
Slopes exposed to terrain traps like large cliffs, jagged rocks, and benches or depressions.
Techniques to Manage Risk:
Watch for signs of unstable snow such as whumpfing, hollow sounds, shooting cracks, or recent avalanches on similar slopes. If observed, back off to simpler terrain.
One person on a slope at a time, even if someone is stuck, and spot from safe areas in dense forest or on high ground.
Snowpack
The snowpack varies in depth throughout the region. Some areas are shallower and more faceted than others, but it seems to be somewhat drainage dependent. In the Cariboos weaknesses exist within and under the 60-80cm of recent storm snow, elsewhere the storm snow is generally settling and strengthening well except where it is wind-loaded. Persistent weaknesses throughout the snowpack, including different buried surface hoar layers and basal facets, create the potential for large step-down avalanches.
New soft wind slab from higher than forecast Northeast winds. Older harder wind slabs below ridge crests, behind terrain features, and in cross-loaded gullies.
Various persistent weaknesses strewn throughout the snowpack, including facets at the base, create the potential for highly destructive avalanches running to valley bottoms. Cornice falls may be the trigger to release these very large avalanches
The dry light storm snow is sluffing in steep terrain on all aspects. In places where the winds have affected the surface, the sluffing may release the storm snow as a slab.Updated by T Riley
Special Message
Deep persistent slab avalanches are becoming less likely but the consequences remain extremely high. Diligence and discipline may be required to resist venturing into complex terrain even if there are no obvious signs of unstable snow. Pre-trip planning should involve talking to trained and experienced riders with local knowledge to determine if a weakness of concern has been removed by recent avalanche activity.
Confidence: Fair
The Northeast winds have been stronger than forecast.
Weather Forecast
Synopsis: Freezing levels remain at valley bottom with treeline temperatures around -10 to -15. Ridge top winds are light to moderate from the north-northeast. Expect little change until Wednesday evening.
Updated by T Riley
Avalanche Activity
A widespread natural avalanche cycle was reported in parts of the Cariboos on Wednesday, corresponding with new snow, warm temperatures, and strong winds. Avalanches were generally up to size 2 and involved only the new snow. Several skier triggered slab avalanches up to size 1.5 were also reported.
Very large avalanches remain possible. They are more likely in areas where the snowpack is (or was) shallow and faceted. These will generally require heavy triggers such as cornice falls, sled tracks digging deep, or smaller avalanches stepping-down.Travel Advisory
Areas to Avoid:
Common trigger points such as convexities or slopes with shallow snow cover where rocks or small trees are poking out.Convex shaped slopes or unsupported slopes where triggering an avalanche is more likely.
Be aware of what is above you. Avoid exposing yourself to overhead hazards like large complex slopes and overhanging cornices.
Slopes exposed to terrain traps like large cliffs, jagged rocks, and benches or depressions.
Techniques to Manage Risk:
Watch for signs of unstable snow such as whumpfing, hollow sounds, shooting cracks, or recent avalanches on similar slopes. If observed, back off to simpler terrain.
One person on a slope at a time, even if someone is stuck, and spot from safe areas in dense forest or on high ground.
Snowpack
The snowpack varies in depth throughout the region. Some areas are shallower and more faceted than others, but it seems to be somewhat drainage dependent. In the Cariboos weaknesses exist within and under the 60-80cm of recent storm snow, elsewhere the storm snow is generally settling and strengthening well except where it is wind-loaded. Persistent weaknesses throughout the snowpack, including different buried surface hoar layers and basal facets, create the potential for large step-down avalanches.
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