Vancouver Island Avalanche Bulletin

Big Thanks to all who attended the fourth annual party for the bulletin on Friday night and of course huge thanks to all the sponsors who made it possible.  We are still tallying things up but it is looking good for the next year for your island avalanche bulletin! Watch our sponsors page for an updated list of all the generous help we received from our supporters.

Valid Until: Saturday 04 February, 2012.

Confidence:  Fair. The coming weather pattern looks quite predictable but freezing levels are less certain. Watch temperatures on Friday as a rapid rise could cause instability in the snow. As the west coast received much more precipitation recently than the central, north and east island hazard there is higher than it is on the east and north island. Ratings above are median values. Check local conditions.

Main Concerns: (Avalanche problems)

Wind Slab - While the north, east and central island alps received only 10-20cm of new snow, the west coast got about 60cm. This snow came with winds strong enough to move the new snow to form slabs on west through north to north east aspects at tree line and in the alpine. These slabs could be triggered by the weight of a human especially in the alpine causing avalanches big enough to bury, injure or kill a person. Whereas mild temperatures will promote settlement in these layers at first on Thursday, if the rise in temperature is too rapid overnight to Friday, as now appears possible, this could cause instability in the snow.

Storm Slab - In areas of higher precipitation storm slab has developed with variations in temperature causing density changes within storm snow. This will remain triggerable by humans certainly in the alpine and possibly at tree line on Thursday. Whereas mild temperatures will promote settlement in these layers at first on Thursday, if the rise in temperature is too rapid overnight to Friday as now appears possible, this could cause instability on the snow.

Cornices - Cornices have continued to build and are a hazard in their own right but can also act as very heavy triggers for large avalanches in the alpine in particular but also possibly at tree line on west through north to east aspects.

Weather:

The west coast mountains on the island saw about 60cm of new snow since Monday whereas the central, east and north island got only 10-20cm. The snow came with moderate winds from the east through south to south west and from the north west on Wednesday. Freezing levels stayed well below tree line except for a short rise to near tree line on Wednesday afternoon.  The outlook is as follows:

Thursday: No new snow. Moderate south west winds rising possibly to strong in the alpine overnight Thursday/Friday. Freezing level around 700 to 1000m and rising rapidly possibly to as high as 2000m or more overnight Thursday/Friday.

Friday: A few cm of snow. Freezing levels dropping from their overnight spike back to 1000m or below. Winds light and variable but mostly from the west.

Saturday: No new snow. Light north west winds. Warm temperatures and strong solar radiation.

Snow Pack:

Wind slabs and storm slab mostly on the west island in areas of higher precipitation will continue to settle with warm temperatures on Thursday. If temperatures rise as much as forecast on Friday the snow could become less stable. The mid and lower snow pack are strong.

Avalanche Activity:

Small skier triggered avalanches less than size one have been observed in the recent snow at tree line.

Travel Advisory:

Extra caution is advised as you move from below tree line to tree line and above into areas where wind has been able to move snow and where storm snow instabilities remain. These instabilities will become less touchy with continued settlement on Thursday but may destabalise with rapid warming overnight to Friday. Give cornices a wide berth both when traveling above and below them. As temperatures rise and the sun comes out, watch for signs of thaw instability in the snow such as moist surface snow, balling and pinwheeling.

Prepared by Jan Neuspiel

There are a few tickets still available for the  Fourth Annual Party for the Bulletin. The event will sell out this year again so don't miss your chance to attend this now legendary party with live music, silent auction and lots of fun. This is the thing that keeps your source of avalanche info going so come out in support. It all happens at the Riding Fool Hostel in Cumberland on Friday 27 January. More info here.

Valid Until: Saturday 28 January, 2012.

Confidence:  Fair. Uncertainty about intensity, timing and freezing levels of coming system. If this system comes in sooner on Saturday, Hazard levels will rise earlier. Watch freezing levels and be aware that when precipitation comes as snow load increases significantly with wind transport.

Main Concerns: (Avalanche problems)

Wind Slab - Strong to very strong winds have created widespread and touchy wind slabs mostly on east through north west aspects from our recent large storms. These slabs remain sensitive to human trigger in the alpine and at tree line and could produce large avalanches particularly in the alpine where slabs are stiff. With wind changing direction to west and north west on Thursday new wind slab has formed in the alpine and at tree line on east through south east aspects. More new wind slabs will form in the alpine and possibly at tree line (depending on how high freezing levels rise) from moderate to strong west to south west winds on Saturday and Sunday.

Storm Slab - Variations in temperature during the past storms have resulted in weaknesses within the storm snow which remain triggerable by humans on all aspects at tree line and in the alpine. New storm slab will form with the coming system on Saturday/Sunday in the alpine and at tree line on all aspects.

Cornices - Great quantities of snow and very strong winds have built cornices which are a hazard in their own right but can also act as very heavy triggers for large avalanches.

Weather:

The island Alps received from 125 to 165cm of snow since Sunday. The snow came with winds that exceeded 100kph at times and came from the SW through to SE. Freezing levels varied but stayed mostly at or below 1000m for the most part except for a rise to tree line for about four hours on Tuesday evening. A ridge of high pressure has shifted winds around to the NW and dropped temperatures since Thursday. The outlook is as follows:

Friday: Mix of sun and cloud. Trace amounts of snow. Moderate west to south westerly winds, freezing levels around 500m.

Saturday: Our next system approaches starting later in the day and giving about 30mm of water by midnight. This will come either as rain or as snow depending on elevations and how high freezing levels rise from 500m to possibly as high as 1800m overnight. Moderate to strong SW winds.

Sunday: 5-35mm of precipitation (most on the west island, least on the north) will come as rain or snow depending on elevation and rate of freezing level drop from as high as 1800m back down to 800-1200m. MOderate to strong west to south west winds.

Snow Pack:

Great quantities of new snow and very strong winds have created wind slab mostly on East through to Northwest aspects. Variations in temperature during the storms have created weaknesses within the storm snow. These remained touchy in tests on Wednesday and Thursday delivering easy results. A crust was formed when freezing levels rose to tree line on Tuesday evening. With cold temperatures since, this crust has thickened to support a skier by Friday. At tree line the crust is less than 1cm thick and it does not reach to the alpine. There is 10-25cm of new snow on top of this crust depending on location. This snow is not bonding well to the crust and has been moved by north and north west wind to create new wind slabs on south to south east aspects. The mid and lower pack are strong.

Avalanche Activity:

A widespread natural avalanche cycle during the past storms with avalanches to size two observed.

Travel Advisory:

In the alpine and at tree line be aware of deep and stiff winds slabs which are sensitive to the load of a human. Stay out of wind affected areas and be aware of what is above you. Winds shifting to west and north west on Thursday have also created new wind slab on east through south east aspects. Also be aware that even where there is not wind slab, instabilities exist withing the storm snow which remain triggerable by humans. Sticking to lower angled and supported terrain in the alpine and at tree line is recommended. Be aware that cornices are a hazard in their own right but can also act as very heavy triggers for large avalanches. Cornice failure is very difficult to predict. Give them a wide berth. Watch the approach of our next system on Saturday. If it arrives earlier than forecast hazard levels will rise sooner. New wind and storm slab will form with this system. Stay out of avalanche terrain on Sunday.

Prepared by Jan Neuspiel

Tickets are on sale now for the Fourth Annual Party for the Bulletin. The event sells out every year so don't miss your chance to attend this now legendary event with live music, silent auction and lots of fun. This is the thing that keeps your source of avalanche info going so come out in support. It all happens at the Riding Fool Hostel in Cumberland on Friday 27 January. More info here.

Valid Until: Wednesday 25 January, 2012.

Confidence:  Fair. Uncertainty about intensity of coming systems and freezing levels later in the forecast.

Main Concerns: (Avalanche problems)

Storm Slab - With significant snowfall amounts and variations in temperature in the forecast, weaknesses will exist within the recent, current and forecast storm snow. Storm slab avalanches will be happening at all elevations and on all aspects.

Wind Slab - Strong to very strong winds have created widespread and touchy, deep wind slabs. Continued snow and strong winds will form yet more wind slabs at tree line and above and particularly from SE to NW aspects.

Weather:

Two storms, one on Friday and a second which started Sunday and continues at time of writing (Sunday afternoon) have delivered from 25cm to over a metre of snow to the Island Alps (least on the north island, most on the west coast). Freezing levels rose to around 1400m during the first storm with strong winds mostly from the SW. The second storm has seen cooler temperatures so far with freezing levels reaching no more than about 300m and very strong winds from the SE shifting to SW. The outlook is as follows:

Remainder of Sunday: 5-15cm more snow. Strong SW winds. Freeing level to around 800m.

Monday: 20 to 40cm snow. Strong SW winds. Freezing level around 900m.

Tuesday: 30 to 60 cm snow. Strong SW winds. Freezing levels to 1500m.

Wednesday: 20 to 25 cm snow. Strong SW winds. Freezing levels to 1500m

Snow Pack:

Wind slab has formed and continues to form in the alpine and at tree line from strong winds mostly from SE to SW. These slabs will be deep and triggering naturally. Weaknesses deeper in the snow pack (surface hoar in places, thin crust at tree line and lower density, colder  snow from earlier in the first storm Friday) will have been the failure plane in avalanches over the week end and will continue to fail and/or be pressed down by the coming load.The mid and lower pack are strong.

Avalanche Activity:

A natural avalanche cycle is certain to be occurring.

Travel Advisory:

When hazard is this high the best way to avoid being caught in an avalanche is to stay out of avalanche terrain. Stick to low angled and well forested areas and stay away from wind effected areas. Avoid steep, open terrain below tree line. Be aware of hazard overhead from avalanche paths and cornices.

Prepared by Jan Neuspiel

Tickets are on sale now for the Fourth Annual Party for the Bulletin. Don't miss your chance to attend this now legendary event with live music, silent auction and lots of fun. This is the thing that keeps your source of avalanche info going so come out in support. It all happens at the Riding Fool Hostel in Cumberland on Friday 27 January. More info here.

Valid Until: Thursday 19 January 2012.

Confidence:  Good.

Main Concerns: (Avalanche problems)

Wind Slab - In the Alpine and exposed tree Line winds will rise to moderate and even strong mostly from the west forming wind slabs from SE through to NW aspects.

Persistent Slab - At higher elevations in the alpine on colder aspects, instabilities deeper in the snowpack could produce large avalanches with large triggers such as cornice falls if they hit just the right spot in a shallow snow pack area.

Weather:
Cold temperatures and little snow have been the main features in our weather. From 7 to 20cm of snow have fallen since Friday. Temperatures at tree line have ranged from around -5 early in the period to -15. Winds have been mostly light and shifted from southerly early in the period to north westerly for the remainder. The outlook is for continued cold arctic air and little or no precipitation. Winds will be from moderate to strong and generally from the west with wind strength increasing significantly as you go up in altitude.

Snow Pack:
The island snowpack varies quite a bit from the east coast to the west and north island and is more complex in the alpine than many are accustomed to seeing on the island. Snow pack conditions described below may or may not apply exactly to the area that you are in so local investigation is important.
There is wind slab at tree line and alpine mostly from southerly winds earlier in the week end which was touchy to human triggers a few days back but is more stubborn now. New slabs will form with forecast winds. Surface hoar has been forming at all elevations and on all aspects. Increasing winds will likely knock this down but it could preserve in areas sheltered from the wind and could be buried as we get new snow. The crust which formed from rain one week ago is thin at tree line elevations and collapses easily on loose dry snow making it a possible failure layer at tree line elevations with load. The mid pack is solid. Persistent layers deeper in the snow pack are delivering hard, if any, results and are likely only a concern in areas of thin snow pack in the alpine and with big loads such as cornice fall. The island snowpack is at around 1.5 metres at tree line and likely considerably more on the west coast though we do not have recent measurements.

Avalanche Activity:
No new natural avalanches have been observed. A few small skier cut wind slabs were observed on Saturday.

Travel Advisory:
In the alpine and at tree line watch for the effects of wind and avoid wind loaded areas. Test small slabs on safe, small features to gauge how they react to load. Give cornices a wide berth.

Prepared by Jan Neuspiel

Date Issued January 11, 2012 at 08:33PM

Valid Until: Monday 09 January, 2012.

 Confidence:  Fair. Uncertainty about precipitation amounts and freezing levels. Danger ratings above are for areas of highest precipitation and wind.

Main Concerns: (Avalanche problems)

Wind Slab - Widespread Wind slab has been created in the alpine and at tree line in the lees of ridges and in cross loaded features from the NW to the SE.

Persistent Slab - Instabilities deeper in the snowpack in the alpine  which date from mid November have significant depths of snow on them where they have not failed in recent storms and could produce large avalanches in those areas. While not widespread they could be triggered from thin slab areas, from heavy triggers such as cornice falls, or from wind slab avalanches stepping down to the deeper weaknesses.

Storm Slab - Weaknesses within and under recent and new storm snow in the alpine are susceptible to natural and human triggers.

Loose Wet: avalanches are possible below tree line on Sunday with rising freezing levels and rain falling on precious storm snow.

Weather:

Since freezing levels dropped on Wednesday and rain turned to snow at all elevations again we have seen between about 2 and 20cm of snow on the island mountains (greatest amounts on the north island). Winds have been strong enough to move snow and to form slabs where there is snow available for transport. Freezing levels have remained low. The outlook is as follows:

Friday night/Saturday: 10-15mm of precipitation. Freezing levels 700m rising to 1400m by the end of the day. Winds moderate to strong SW.

Sunday: 20-40mm of precipitation. Freezing levels continuing to rise to 2000 meters or more. Winds strong SW.

Monday: 5-15mm of precipitation. Freezing levels dropping from 2000m down toward 1000m and below. Winds lightening and turning NW.

Snow Pack:

The island snowpack varies quite a bit from the east coast to the west and north island and is more complex than many are accustomed to seeing on the island. Snow pack conditions described below may or may not apply exactly to the area that you are in so local investigation is important. Wind slabs have been formed and continue to form in the alpine all over the island and at tree line as well on the north island. Rain has soaked the surface of the snow pack on Wednesday up to tree line. Weak facet/crust layers have been the failure plane for avalanches during the last storm cycle but likely persist in places in the alpine. The mid pack is strong. Basal weaknesses are not likely a concern in the island snowpack anymore except perhaps in rare places in the highest alpine with shallow snowpack and smooth ground cover.

Avalanche Activity:

Evidence of wet snow avalanches has been observed on the east and north island below tree line from the rain event of Wednesday.

Travel Advice: In the alpine and at tree line in places which had enough snow and wind choose conservative lines and watch for clues of instability such as cracking and shooting cracks. Assess conditions continually as you travel. Always be on the lookout for wind slab and avoid freshly wind loaded features. Be aware that cornices have formed and are both hazards in their own right but can also act as large triggers to avalanches and are difficult to predict. Skiing is good below tree line for Saturday but things will turn again with precipitation, rising freezing levels and rain on Sunday making hazard high again in the alpine and likely considerable at tree line as new loading by either snow or rain lands on existing weaknesses.

Prepared by Jan Neuspiel

Valid Until: Wednesday 4 January, 2012.

UPDATE Tuesday 3 January, 2012, 16:25

Freezing levels have reached only as high as tree line during heavy precipitation today meaning that we have been getting a lot of snow rather than rain at these elevations. This coupled with strong winds will bring the hazard at tree line to HIGH on Wednesday.

Confidence:  Fair. Timing and intensity of precipitation and in particular freezing levels are uncertain.

Main Concerns: (Avalanche problems)

Wind Slab - Wind slab has been created by winds predominantly from the SW but also around to the SE in the lees of ridges and in cross loaded features. These slabs date from days ago as well as more recently but they remain triggerable by increased loads from humans and from forecast precipitation.

Persistent Slab - Increased load from snow, rain or wind driven snow could bring instabilies deeper in the snowpack on all aspects to the point where they will fail naturally.

Storm Slab - If freezing levels do not rise as high as forecast below and precipitation comes as snow, it will be in sufficient quantity to cause a natural avalanches on layers within or at the base of the storm snow or on deeper layers as described above.

Weather:

The island alps saw little precipitation over the weekend. Winds have been strong enough to  move snow. At time of writing (Monday 14:00) our latest system has just hit the east coast of the island. The outlook is as follows:

Monday: 10-25mm of precipitation. Freezing levels 1200-2000m (uncertainty about this). Winds strong SW.

Tuesday: 40-80mm of precipitation (greatest amounts on the west coast). Freezing levels seem likely to head well over the tops of the island mountains though again we lack certainty about freezing levels. Winds strong SW.

Wednesday: 50-60mm of precipitation. Freezing levels making their way from 2000m down toward 700m. Winds strong SW easing slightly and becoming more W.

Snow Pack:

The island snowpack varies quite a bit from the east coast to the west and north island. Snowpack conditions described below may or may not apply exactly to the area that you are in so local investigation is important. In the alpine and at tree line thick wind slabs overlie previous storm snow and weak faceted snow at crusts. This crust/facet layer still delivers planar test results in the moderate range and though it is deep enough in the snowpack in many places that triggering is stubborn, with increased loads from coming precipitation we expect to see failures on this layer. The mid pack is very strong. The base of the snowpack has faceted crystals which are likely too strong to fail in most places.

Avalanche Activity:

Skier cut wind slabs producing avalanches to size 1 on Sunday.

Travel Advice:

With heavy precipitation likely coming largely as rain it seems unlikely that you'll want to be in the mountains over the next few days. If you do choose to go out stay out of avalanche terrain in the alpine on Tuesday and Wednesday and only consider it at tree line if you have advanced snow stability evaluation and route finding skills. With increased load, weaknesses deeper in the snowpack will likely be activated in the alpine and possibly at tree line. Notice that cornices have been built up in the last while. These are hazards in their own right and are large potential triggers for avalanches. With heavy rain a distinct possibility, their failure seems likely. Give them a wide berth.

Prepared by Jan Neuspiel

Valid Until: Saturday 31 December, 2011.

Confidence:  Moderate. While the pattern is clear, exact timing and intensity can easily vary from what is forecast below.
Ratings above are for areas of highest precipitation. Watch precipitation amounts for the area you are traveling in.

Main Concerns: (Avalanche problems)

Wind Slab - Wind slab has been created on weak layers by winds predominantly from the SW. These slabs will continue to form with more new snow and wind in the forecast.

Storm Slab - With sufficient quantities of new snow and snow driven by wind, load will increase on weak layers making natural avalanches likely on all aspects in the alpine and possible at tree line and below.

Weather:

It's been more of the same with a series of frontal systems bringing between 20 and 70mm of water to the island mountains since Monday (greatest amounts on the west coast, lowest on the north and east island with median amounts in the center of the island). All of this precipitation came as snow to the high alpine but rain made it's way up to around tree line for some time. Winds were moderate to strong mostly from the SW to SE. The outlook is for a continuation of the same pattern as follows:

Wednesday/Thursday: one frontal system continues overnight Wednesday before a short break and then another front starting Thursday afternoon. Total accumulations for overnight Wednesday and Thursday 30-50mm. Freezing levels dropping from 1500m Wednesday to 500-900m for Thursday. Winds moderate to strong SW during precipitation and briefly NW during the break between systems.

Friday: Continuation of Thursdays system followed by another break between systems. An additional 10-25mm precipitation. Freezing levels around 900m. Winds moderate to strong SW during the system and again shifting to NW during the break.

Saturday: A short lived ridge of high pressure to bring a mix of could and sun in the morning before the next system hits later in the day. Freezing levels 300-500m in the morning and light to moderate NW winds. Just a trace of precipitation possible earlier in the day with more coming later.

Snow Pack:

The island snowpack varies quite a bit from the east coast to the west and north island. Snowpack conditions described below may or may not apply exactly to the area that you are in so local investigation is important. In the alpine and at tree line thick wind slabs overlie weak faceted snow at crusts. These slabs are easily triggerable by human loads and render easy, planar test results. Areas below tree line which are sheltered from both wind and sun may have surface hoar lurking below. The mid pack is very strong. The base of the snowpack has faceted crystals which are likely to strong to fail in most places though with increasing loads some very specific areas (shallow and rocky in the highest alpine only) may warrant attention.

Avalanche Activity:

Natural and human triggered avalanches to size 1.5 have been observed. Bigger avalanches become possible in the time frame of this forecast as snow and wind continue to build deeper slabs across larger expanses of terrain and bring loads to levels at which they will trigger deeper instabilities.

Travel Advice:

Staying out of avalanche terrain during times of high hazard is your best bet for avoiding getting caught in a potentially fatal avalanche. If you don't know what avalanche terrain is, take an avalanche course to learn to distinguish it. Stick to low angled and well forested slopes and stay away from wind loaded areas near ridge crests and in places which are "cross loaded". Watch for signs of instability in the snow such as natural avalanches, "whumpfing" sounds, cracking, shooting cracks and hollow sounds. Remember to be aware of what is above you and below you: In poor visibility it is possible to be unaware of avalanche terrain primed for release above you and remain aware that even small avalanches can have serious consequences when they drag you into a terrain trap below you such as trees and cliffs.

Prepared by Jan Neuspiel