Mountain Conditions Report

Mar 27, 2009

2009-03-27T22:10:00.000-07:00

Whistler Avalanche conditions

For Fri Sat Sun
Alpine: Considerable Considerable Considerable
Treeline: Moderate Considerable Moderate
Below Treeline: Moderate Moderate Moderate
Avalanche Danger Rating Descriptions

Travel Advisory:
Large slab avalanches continue to be reported by ski operators across the Coast Mountains. Wind loaded soft slabs are sitting over variable surfaces in the alpine and treeline. Areas of stiff windslab are loaded onto exposed alpine features. Caution is advised around any previously shallow rocky areas that are now loaded with storm snow. Although cooling temperatures have tightened up the snowpack, we have seen widespread natural and skier triggered deep slab avalanches stepping down to the December facets. Remember that sun warming may make the snowpack more fluid and ready to react. Give cornices a wide berth as cornices have triggered many of the recent large avalanches.

Avalanche Activity:
Large slab avalanches continue to be reported throughout the Coast Mountains from steep shallow areas. These avalanches are running into skiable terrain. Widespread natural avalanche activity with dozens of deep size three slabs, and even a size four, ran last weekend. Triggers for this cycle ranged from naturals and cornice faliures to skier-remote and explosives triggered avalanches. This avalanche activity has settled down somewhat since Monday. The deeper releases were all between 1700m and 2300m on all aspects. One fracture line profile at 1775m on a NE aspect showed the bed surface to be surface hoar on a crust. Most large avalanches in the alpine appeared to involve the Dec 6 facet layer.

Snowpack:
Wind loaded snow is sitting on a variety of surfaces in the alpine and treeline. There continue to be several persistent weak layers in the snowpack. Stepped fracture lines would indicate that the weaknesses from December, February and March are all at or near their threshold. Stability tests in profiles are indicating hard shears, but the widespread easily triggered large avalanche activity indicates a more acute weakness. As always, the areas to avoid are those where the snowpack is shallow and the weak basal layers are more extensive.

Update Feb 16, 2009

2009-02-16T08:27:00.000-08:00

Whistler Alpine conditions

Snowpack depth varies

-320cm on the pemberton icecap at 8000ft
-244cm at 7500ft north aspect spearhead glacier
-180cm at 6800ft decker glacier
-144cm at most treeline locations
-110cm backside of the main crest of the coast mountains
-70cm inland

Good skiing can be found in most areas above and below treeline.

Tuesday, January 20, 2009

2009-01-21T06:51:00.000-08:00

Whistler Avalanche conditions

:�Tuesday, January 20, 2009 7:51 AM
For: Tue Wed Thu
Alpine Considerable Considerable Considerable
Treeline Considerable Considerable Considerable
Below Treeline Moderate Moderate Moderate

Note: If you do manage to trigger down to the facet/crust layer a stiff slab now sits on top of it creating an avalanche the would most likely be unsurvivable due to large frozen chunks of snow that would grid you into pulp.

Travel Advisory:

The amazingly warm temperatures are finally starting to affect the surface layers on solar aspects. The upper snowpack is warming and trending towards strengthening, but the underlying facet weakness remains relatively unchanged. Numerous large slab avalanches have been observed over the past week. Expect continued natural avalanche activity with the real possibility of skier triggered activity as well. Many results are likely to be very large. The avalanche danger will increase through the day.

Avalanche Activity:

We have been seeing natural remotely triggered avalanches, even in low angle terrain. Explosive testing and ski cutting carried out during the past week has produced numerous slab avalanches up to two meters in depth. They have been failing in the storm snow and in the facets above the December 6th crust. Some slopes at treeline elevations have run on a layer of depth hoar in the rocks and on the heather. Many settlement whumphs have also been felt. At lower elevations, rainfall produced widespread loose sluffing and snowballing. The unseasonally high freezing levels and solar radiation have produced wet loose slides up to size 2 on solar aspects and cornice failures have triggered slab avalanches up to size 2 as well.

Snowpack:

The current snowpack is very atypical for the West Coast. The shallow early December snowpack was exposed to prolonged cold temperatures which caused it to become weak and faceted. Depth hoar formed in shallow rocky terrain. Compounding this problem is the underlying Dec.6 raincrust that provides a nice hard sliding surface. The buried facets and depth hoar above and below the December 6 crust are likely the weak layers causing the settlement whumphs. The crust/facet combo is now buried up to 200 cm below the surface on some lee slopes. Not all start zones are running on the crust, but you can expect more widespread activity as the load above it grows. Rocky terrain is very rotten and will be particularly prone to deeper releases in the future. Below treeline terrain is quite variable depending on aspect and elevation. Some areas have been crusted over while others have a layer of surface hoar sitting on winterlike snow.

Weather:

Mostly clear skies and very warm alpine temperatures are forecast to last into mid week. As the ridge begins to break down we should see increasing cloud cover on Thurs and Fri with freezing levels gradually falling to around 1000m, and snow flurries possible on Saturday. Enjoy the sunshine while it lasts, as payback time will arive at some point this winter!!

Backcountry travel is not advised at this time due to the weak and unpredictable nature of the snowpack

Snowpack tightening up

2009-01-16T08:34:00.000-08:00

Whistler Avalanche conditions

Friday, January 16, 2009 7:07 AM

For: Fri Sat Sun
Alpine Considerable Considerable Considerable
Treeline Considerable Considerable Considerable
Below Treeline Moderate Moderate Moderate

Travel Advisory:

A rapid change to warm temperatures in the alpine will add significant stress to the snowpack. While the surface layers have been gaining strength, the underlying facet weaknesses remains relatively unchanged. Numerous large slab avalanches have been observed over the past few days. Expect continued natural avalanche activity with the real possibility of skier triggered activity as well. Many results are likely to be very large.

Avalanche Activity:

We have been seeing natural remotely triggered avalanches, even in low angle terrain. Explosive testing and ski cutting carried out during the past week has produced numerous slab avalanches up to two meters in depth. They have been failing in the storm snow and in the facets above the December 6th crust. Some slopes at treeline elevations have run on a layer of depth hoar in the rocks and on the heather. Many settlement whumphs have also been felt. At lower elevations, rainfall produced widespread loose sluffing and snowballing. The unseasonally high freezing levels and solar radiation have produced wet loose slides up to size 2 on solar aspects, cornice failures have triggered slab avalanches up to size 2 as well.
Snowpack:

The current snowpack is very atypical for the West Coast. The shallow early December snowpack was exposed to prolonged cold temperatures which caused it to become weak and faceted. Depth hoar formed in shallow rocky terrain. Compounding this problem is the underlying Dec.6 raincrust that provides a nice hard sliding surface. The buried facets and depth hoar above and below the December 6 crust are likely the weak layers causing the settlement whumphs. The crust/facet combo is now buried up to 200 cm below the surface on some lee slopes. Not all start zones are running on the crust, but you can expect more widespread activity as the load above it grows. Rocky terrain is very rotten and will be particularly prone to deeper releases in the future. Below treeline terrain has a weak layer on the ground. We were seeing some avalanche activity at lower elevations, but the snowpack has since received a good rainfall and should have run in most areas.
Weather:

Mostly clear skies and very warm alpine temperatures are forecast to last through the weekend.

Poor conditions

2009-01-02T08:57:00.000-08:00

Whistler Avalanche conditions

Last Updated: Friday, January 02, 2009 7:14 AM
Fri Sat Sun
Alpine High
Treeline High
Below Treeline Considerable
Avalanche Danger Rating Descriptions

Travel Advisory:
The current avalanche conditions are unusual for the coast. The skiable lines that have filled in are for the most part where the avalanche hazard is at its worst. Ongoing snowfall and sometimes very strong winds have loaded a variable series of hard and soft slabs over the weak lower snow pack. While some lines are slowly looking a little more filled in, the underlying weaknesses are already reacting to small loads. Avalanches are being remotely triggered as people are approaching slopes, while lower angle areas are settling or "whumphing" repeatedly and even after explosives have been used in some areas. Travel with caution as there are still many barely covered hazards below the new snow.

Avalanche Activity:
Explosive testing and ski cutting carried out over the past few days have produced numerous slabs up to two meters in depth. They have been failing in the storm snow and in the facets above the December 6th crust. Many settlement ?whumphs? were felt as well. Some avalanches running from small start zones near treeline were observed to channel into ground features while entraining numerous boulders resulting in nasty debris piles.

Snowpack:
The upper snowpack is upside down; areas of very hard windslab alternate frequently with deep soft slabs. Shallow areas like west aspects have verythin surface weaknesses over depth hoar crystals. These buried facets and depth hoar above and below the December 6 crust are weak and very likely the cause of the settlement whumphs. This crust may be now buried up to 100 cm below the surface. We have only seen limited activity running on the crust, but you can expect that it will begin to happen as the load above it continues to grow. Rocky terrain is very rotten and will continue be particularly prone to deeper releases in the future.

Weather:
Cool and unsettled conditions are expected over the next few days until a weathe5 system arrives on Sunday.

2008-12-31T16:00:00.000-08:00

Whistler Avalanche conditions

Backcountry Avalanche Advisory
Last Updated: Wednesday, December 31, 2008 2:34 PM
Wed Thu Fri
Alpine High
Treeline High
Below Treeline Considerible
Avalanche Danger Rating Descriptions

Travel Advisory:
Ongoing snowfall and sometimes very strong winds are loading a variable series of hard and soft slabs over the weak mid snow pack. While some lines are slowly looking a little more filled in, the underlying weaknesses are already reacting to small loads. Avalanches are being remotely triggered as people are approaching slopes, while lower angle areas are settling or "whumphing" repeatedly and even after explosives have been used in some areas. Travel with caution as there are still many barely covered hazards below the new snow.

Avalanche Activity:
Explosive testing and ski cutting carried out over the past few days have produced numerous slabs up to two meters in depth. They have been failing in the storm snow and in the facets above the December 6th crust. Many settlement ?whumphs? were felt as well. Some avalanches running from small start zones near treeline were observed to channel into ground features while entraining numerous boulders resulting in nasty debris piles.

Snowpack:
The upper snowpack is upside down; areas of very hard windslab alternate frequently with deep soft slabs. Shallow areas like west aspects have ver4ythin surface weaknesses over depth hoar crystals. These buried facets and depth hoar above and below the December 6 crust are weak and very likely the cause of the settlement whumphs. This crust may be now buried up to 100 cm below the surface. We have only seen limited activity running on the crust, but you can expect that it will begin to happen as the load above it continues to grow. Rocky terrain is very rotten and will continue be particularly prone to deeper releases in the future.

Weather:
We are expecting more wind and possibly more heavy precipitation over the next few days.

December 23, 2008

2008-12-23T17:06:00.000-08:00

Whistler Avalanche conditions

Travel Advisory:
20 cm. of low density snow has fallen during the past several days. Mountain top winds have been moderate to strong at times, resulting in some transport of the storm snow. Some slopes at tree-line are approaching the threshold for avalanche activity, but below tree-line elevations still do not have much of a snowpack. In the alpine, glaciers and permanent snow slopes have more coverage, but other slopes still have widespread rock anchors visible. Travel with caution as the new snow may be barely covering numerous underlying hazards.

Avalanche Activity:
In the alpine terrain, the storm snow has formed pockets of soft slab that were observed to be reactive to the weight of a person yesterday. The debris has been unconsolidated, with little in the way of destructive potential.

Snowpack:
The storm snow is sitting on a variety of old surfaces - windslab, sustrugi and in some places the December 6th crust. In the upper 50 cm of the snowpack you may find two pencil density windslabs that are both sitting on softer layers. Facetted layers above and below the Dec 6 crust are also very weak. Compression tests are producing shears below the windslabs and also above the crust. In the coming weeks when we finally begin to see more of a normal snowfall pattern and these layers get more of a load, deeper slabs releases could be a possibility.

Flute Backside. December 23, 2008
Ton's of stuff poking through still. Rocks, creeks, branches.
Base:
Top: 110cm
Bottom: 80cm

Windslabs at 20cm and faceted layers observed at 50cm with 10cm raincrust, and more facets under.

Compression tests: moderate on 20cm and 50cm
Shear: easy at 50cm above crust

Weather:
Cloud cover will increase throughout the day today as a weak system arrives onshore bringing snow flurries tonight and tomorrow morning. Another slightly stronger system is forecast to arrive onshore tomorrow evening. Cnt?d cool and unstable weather on Thursday with another stronger system forecast for Friday and Saturday with more seasonable temperatures.

Moderate

2008-12-15T07:24:00.000-08:00

Whistler Avalanche conditions

	Sun	Mon	Tue
Alpine
Treeline	Below Threshhold	Below Threshhold	Below Threshhold
Below Treeline	Below Threshhold	Below Threshhold	Below Threshhold
Avalanche Danger Rating Descriptions

Travel Advisory:

Some slopes at tree-line are approaching the threshold for avalanche activity, but below tree-line elevations still do not have much of a snowpack. In the alpine, glaciers and permanent snow slopes have more coverage, but other slopes still have widespread rock anchors visible. Some new snow has finally arrived in the alpine, but don't go too crazy yet as it is only barely disguising many of the underlying hazards. Strong outflow winds today will be scouring what little snow there is on windward aspects.

Avalanche Activity:

There has been little in the way of avalanche activity over the past few days. There is isolated areas of thin stiff windslab that may be triggerable by the weight of a skier.

Snowpack:

The 20-25 cm of snow that has fallen since last weekend is resting on a melt-freeze crust that formed after temperatures fell on Saturday night. A layer of mixed forms lies immediately above the crust and compression tests are producing moderate shears within this layer. Strong NE winds today are moving the low density surface layers and forming pockets of windslab on lee slopes. The Arctic air that arrived overnight will promote faceting in the upper snowpack, particularly in areas where there is little in the way of coverage.

Weather:

Cold temperatures and little precipitation are forecast for the next two days. The temperatures should moderate on Tues/Wed and then return to more arctic outflow for the rest of the week.

Travel with a partner and be equipped and prepared for self-rescue.

Alpine update

2008-12-10T08:29:00.000-08:00

Last Updated: Wednesday, December 10, 2008 7:38 AM
For Wed Thu Fri
Alpine
Moderate

Treeline Below Threshhold
Below Threshhold
Below Threshhold

Below Treeline Below Threshhold
Below Threshhold
Below Threshhold

Avalanche Danger Rating Descriptions

Travel Advisory:
Treeline and below treeline elevations have little in the way of a snowpack, so avalanches are very unlikely to occur. In the alpine, glaciers and permanent snow slopes have more coverage, but other slopes still have widespread rock anchors visible. Some new snow has finally arrived in the alpine, but don't go too crazy yet as it is only barely disguising the underlying hazards.

Avalanche Activity:
Ski cutting on Sunday produced a few small soft slabs that were running a few cms above the melt freeze crust. Although these soft slabs have since settled and the shears have tightened-in, the new windslabs that developed throughout the day yesterday will likely still be reactive to ski testing on some lee slopes today.

Snowpack:
At 2200m on north facing glaciers there is up to 200 cm of snow. Several crusts have been observed within this snowpack, the most recent having formed after rain and freezing rain moistened the surface layers of snow on Friday and Saturday. The 20-25 cm of snow that has since fallen is now resting on this crust and appears to be bonding well to it. An easy shear was observed yesterday at the interface of a stiff windslab and the underlying softer layer of snow.In some areas you may still find layers of moist snow below the uppermost crust. Once the cold airmass arrives next weekend, the upper snowpack will begin to deteriorate rapidly, particularly in areas where the snowpack is still relatively shallow and rocky.

Weather:
The forecast is calling for mainly cloudy skies with a chance of Flurries today, and a mix of sun and cloud for tomorrow. Another system is forecast to arrive on Friday. Cold outflow conditions are expected to develop over the weekend.

Tips UP!!

2008-11-27T07:03:00.000-08:00

Mountain Conditions
November 27, 2008
Packed and or untracked boot top powder mixed with rocks, boulders, stumps etc.

Snowbase: 39.8cm

Tips UP!!

Too much warm air

2008-11-15T08:09:00.001-08:00

A warm flow of air off the pacific is giving Whistler plenty of precipitation along with high freezing levels. The outlook into late next week looks bad for the mountains. Freezing levels will be high for all incoming systems through Thursday next week.

The freezing level is currently around 2300m. Last night saw winds at the top of Whistler mtn blowing 104km/ph.
Alpine base is 20cm and shrinking.

On a positive note environment canada is calling for below average temperatures through January, combine that with all this precip, and things could be looking up.

First snow that should stay

2008-11-04T22:36:00.000-08:00

We've received anywhere from 20-30cm of new snow during the last storm cycle around 1800m. Winds were strong out of the SE. Alpine areas above 2200m would most likely have 60cm. More storms are forecast through the end of the week bringing rising freezing levels. Snow was down to the village this morning briefly.

Meltdown

2008-06-14T08:02:00.000-07:00

Alpine conditions

1ft-2ft of snow left at 6000ft.

Conditions Report

2008-06-04T18:36:00.000-07:00

http://www.weatheroffice.com/scripts/nphshowarf.pl?html&1010.txt

April 11, 2008

2008-04-11T09:50:00.000-07:00

Whistler Avalanche conditions

April 11, 2008

Alpine: Moderate

Treeline: Low

Below Treeline: Low

Travel Advisory: A gradually increasing load of low density snow has been accumulating over the old stiff and or crusty interface dating back to April 2nd. On north facing aspects up to 30cm of snow can be found resting on this layer. The surface layers of snow have rapidly become temperature affected on any slopes exposed to the brief appearances of the sun during the past few days. Elsewhere the soft slabs that have been formed by moderate southerly winds may remain reactive to the weight of a person in some isolated areas. Rapidly rising freezing levels on Friday and Saturday may produce a widespread spring avalanche cycle involving at least the surface layers of snow on steep solar aspects. There is always the possibility as well that a moist sluff in motion could step down to some weakness buried deeper in the snowpack.

Avalanche Activity: Explosive testing on Monday morning produced a few size 1.0 to 1.5 soft slabs that were propagating easily. Small natural sluffs were also observed to have occurred. Although the storm snow layers have rapidly been settling and gaining strength, you can expect to find some soft slabs on lee slopes that remain reactive to the weight of a person around some isolated terrain features on more northerly aspects. Any appearances of the sun today could rapidly produce moist sluffing in steep rocky terrain.

Snowpack: Ridge lines remain predominantly scoured down to the old melt freeze crust and solar aspects have a variety of weaker crusts in the upper layers. The early April crust has proven to be a failure plane in some areas particularly in terrain where the old surface remained smooth and was not roughened up. North aspects have retained winterlike conditions, although that may change with the forecast warm temperatures over the weekend.

Weather: Mainly cloudy conditions are forecast for today, tonight and Saturday. Some breaks and flurries can be expected. Temperatures will begin warming today and the freezing level should get up to 2500m. by Saturday. More clouds and flurries are on the way for next week with temperatures cooling again on Monday.

Late season powder

2008-03-30T16:52:00.001-07:00

A recent late season dump gives one last taste of winter as things get deep again.

South Coast Avalanche Forecast
Date/Time issued:
Friday, March 28, 2008 at 4:00 PM
Valid until:
Monday, March 31, 2008 at 6:00 PM
Next Scheduled Update:
Monday, March 31, 2008

---------- Sea-to-Sky ----------
Saturday Sunday Monday
Alpine 3 - CONSIDERABLE 2 - MODERATE 2 - MODERATE
Treeline 2 - MODERATE 2 - MODERATE 2 - MODERATE
Below Treeline 1 - LOW 1 - LOW 1 - LOW
---------- Duffy Lake & Inland Areas ----------
Saturday Sunday Monday
Alpine 3 - CONSIDERABLE 3 - CONSIDERABLE 3 - CONSIDERABLE
Treeline 3 - CONSIDERABLE 2 - MODERATE 2 - MODERATE
Below Treeline 2 - MODERATE 1 - LOW 1 - LOW

Confidence:
Primary Concerns:
Persistent Slab:
40-80cm of storm snow is now sitting on a crust and surface hoar layer from March 10/11 or on sun crusts on south aspects. Wherever this storm snow has formed into a slab, from wind or temperatures, there are human triggered avalanches occurring. This is a particular concern in the Duffy Lake and Inland Areas.

Solar Radiation:
Every day as the south aspects get soft and moist the avalanche danger is rising in response. What is rated as Moderate or Low for the morning freezing temperatures will climb to Considerable or High with the intensity of the sun. My concern is for south facing bowls and large drooping cornices.

--------------------------------------------------------------------------------

Travel Advisory

The valleys are certainly starting to feel like spring, still chilly though. In the mountains it is still very much winter. Given the variety of tricky weak layers with deep wind slabs scattered around the region it will be wise to use caution in any steep, convex or complicated terrain. As the wind and time work the storm snow into more of a slab it will become more important to choose conservative terrain. Even at tree line choosing terrain that is well supported, avoids terrain traps and is lower angle will help reduce your exposure.

Avalanche Activity

The tricky nature of the existing weak layer on the Coast was clear from an incident yesterday north of the Duffy area where a skier was caught and partially buried after triggering a slab on the March 10/11 crust. Numerous loose natural and human triggered sloughs off north aspects will continue through the weekend. Cornices are also continuing to drop off.

Snowpack

40-60cm of storm snow is making for thigh deep foot penetration. The wind is starting to form this up into a soft slab. There are moderate and sudden planar shears being reported down 40-50cm on the March 10/11 layer. South aspects are moist in the mid day and forming into a crust as the diurnal cycle continues. Below the upper snow pack is a very firm and dense mid and lower snow pack which will continue to provide fast traveling for the as long as the weather continues to be cool.

The weather is forecast to bring 5-10cm of snow to the alpine by Saturday night. With convective cells imbedded some valleys may get more intense short bursts of snow fall. Clouds and light flurries are expected for Sunday. The winds will be in the moderate 30km/hr range from the East and swing through the south and west by Sunday. The temperatures will remain cool through the weekend with freezing levels not getting above 800 metres. Monday will bring somewhat clearer conditions.

February 26, 2008

2008-02-27T07:18:00.001-08:00

Whistler Avalanche conditions

February 26, 2008

Alpine: Low

Treeline: Low

Below Treeline: Low

Travel Advisory: A dusting of fresh snow fell Feb 23 and it is overlying a variety of old surfaces. Exposed alpine terrain is wind affected and a sun crust dominates solar aspects. Cornices have grown and are fragile so give them a wide berth from both above and below. Keep in mind that a surface slab in motion has the potential to step down to older buried windslabs and wind-hammered surfaces.

Avalanche Activity: Cloud cover today will help preserve the melt freeze crust on solar aspects, so unless the sun makes an appearance there should be little sluff activity. Cornices have been reactive to small triggers, stay well back. The most recent activity on the Dec 04 Crust and facet layer was on January 21st and was initiated by a large cornice fall.

Snowpack: Sunny mild weather last week resulted in the formation of a sun-crust on any sun exposed slopes. The crust varies in strength depending on the aspect and steepness of the terrain. North aspects have maintained winter like snow in spite of the warm temperatures. Strong east and northeast winds Sunday moved small amounts of loose snow around, but there was little snow available for transport and any resulting windslabs are quite small. At treeline and below treeline elevations several surface hoar and facet layers are now buried anywhere from 40-80cm in depth. There have been no reports of any whumphing, cracking, or any isolated skier and machine triggered avalanche activity on these buried weaknesses since last week. The Dec 4th crust and facet layer lies dormant for now, buried deeply within our snowpack in most areas.

Weather: We can expect to see clouds and flurries today with the freezing level rising to 1400m by this afternoon. Periods of snow with small amounts of accumulation are forecast for tonight and Wednesday. There will be sunny breaks on Thursday and there is a possibility of heavy snow fall on Friday.

February 20, 2008

2008-02-21T07:23:00.000-08:00

Whistler Avalanche conditions

February 20, 2008

Alpine: Moderate

Treeline: Low

Below Treeline: Low

Travel Advisory: Exposed alpine terrain is widely wind affected. Pleasant spring like days have left a melt freeze crust on solar aspects. Cornices have been fragile, so give them a wide berth from both above and below. There have been several reports of cornice failures propagating large slab avalanches in the area. Keep in mind that a surface slab in motion has the potential to step down into older buried weaknesses.

Avalanche Activity: Snowballing and point releases to Size 1 have been widespread on solar aspects. Cornices have been very reactive to small triggers, so stay well back. The most recent activity on the Dec 04 Crust and facet layer was on January 21st and was initiated by a large cornice fall.

Snowpack: The strong winds have created a wide variety of conditions in the alpine and treeline terrain. There are extensive areas of stiff windslab in exposed terrain, and areas of less wind affected unconsolidated snow in sheltered terrain. On solar aspects the upper 5-10 centimeters has been through a multiple day melt-freeze cycle. Below the new snow layers are several layers of buried windslab. At treeline and below treeline elevations several surface hoar and facet layers are now buried anywhere from 40-80cm in depth. Now that these layers have received a critical load, there have been reports of whumphing and cracking on some treeline slopes, as well as isolated skier and machine triggered avalanche activity on these buried weaknesses. The Dec 4th crust and facet layer seems dormant for now, buried deeply within our snowpack in most areas.

Weather: Weak low pressure systems are expected to bring cloud with mild day time temperatures to our area for a few days. No significant changes are expected through the weekend.

February 13, 2008

2008-02-14T08:01:00.000-08:00

Whistler Avalanche conditions

February 13, 2008

Alpine: Considerable

Treeline: Moderate

Below Treeline:Low

Travel Advisory: A series of storms have swept through our region depositing approximately 66cm of snow during the past week. Winds accompanying the bulk of the snowfall since Feb 7th have been strong. The freezing level on Saturday rose to 1700m and some areas experienced periods of freezing rain mist. Wind exposed slopes will be scoured, while you can expect to find some soft windslabs in lee terrain and around terrain features on more North facing aspects. Cornices have grown and are fragile so give them a wide berth from both above and below. Keep in mind that a slab avalanche triggered within the storm snow has the potential to step down to deeper instabilities in the snowpack.

Avalanche Activity: Explosive and ski testing this morning was producing mostly size 1.0 to 1.5 soft slabs with crowns up to 20cm in depth, stepping down deeper to earlier storm snow layers in some isolated areas. Cornices were observed to be very reactive with some large cornice falls triggered with small bombs. The most recent activity on the Dec 04 Crust and facet layer was on January 21st and was initiated by a large cornice fall.

Snowpack: The strong winds have created a wide variety of conditions in the alpine and treeline terrain. You will find pockets of soft windslab, scoured surfaces, and areas of less wind affected new snow as you descend closer to the treeline. Below the new snow layers are several layers of buried windslab, as well as old hard wind-hammered surfaces. You may also feel a weak ice lens that developed with the freezing mist on Saturday. At treeline and below treeline elevations several surface hoar and facet layers are now buried anywhere from 40-80cm in depth. Now that these layers have received a critical load, there have been reports of whumphing and cracking on some treeline slopes, as well as isolated skier triggered avalanche activity on the most recent surface hoar layer. The December 4th raincrust and facet crystal weakness is well buried in most areas, and although it has gradually been gaining strength, it has continued to pop up sporadically. Its unpredictable and persistent nature has been problematic and backcountry travelers should continue to be cautious. The deep slab releases have generally appeared to initially fail in a shallow part of the slab in rocky start zones, propagating into the deeper areas.

Weather: Mainly sunny skies should prevail today, with increasing cloud cover tomorrow on the approach of a weak system. Periods of flurries are expected to persist right thru the weekend with sunny breaks inbetween.

Blower Pow

2008-02-03T08:29:00.000-08:00

Whistler Avalanche conditions

February 03, 2008

Alpine: Moderate

Treeline: Moderate

Below Treeline: Low

Travel Advisory: The storm snow that has fallen throughout the past week was accompanied by light winds resulting in very little consolidation of the surface layers. Last night's moderate winds from the East have possibly formed isolated pockets of soft slab. Some areas the wind pressed surfaces from last week's outflow winds are still very much in evidence. Keep in mind that large unpredictable avalanches are still very much a possibility, particularly if a cornice fall is involved.

Avalanche Activity: Natural point released sluffs from steep start zones and on solar aspects were observed yesterday. Explosive testing produced size one surface avalanches. The slabs that were moving with explosive and ski testing on January 31 appear to have tightened in. The most recent activity on the Dec 04 Crust and facet layer was on January 21st and was initiated by a large cornice fall. New cornice tabs are soft and have been observed to be very fragile.

Snowpack: The snow that has fallen since last Saturday is loose sitting on a variety of old hard surfaces that were created by last week's strong NE winds and sun. At treeline and below treeline elevations, surface hoar up to 10mm in size is overlying a layer of faceted crystals. These layers are now buried by 50-70 cm of loose storm snow. Adjacent to creek beds these crystals are much larger and could provide an easy failure plane for future avalanches. The December 4th raincrust and facet crystal weakness is well buried in most areas, and although it has gradually been gaining strength, it has continued to pop up sporadically. Its unpredictable and persistent nature has been problematic and backcountry travelers should continue to be cautious. The deep slab releases have generally appeared to initially fail in a shallow part of the slab in rocky start zones, propagating into the deeper areas.

Weather: An upper ridge of high pressure will produce mainly sunny skies for today. Some cloud will move into our area tonight as a small disturbance approaches our area for Monday. A more organized system should bring periods of snow for Tuesday. The freezing level is expected to remain at the valley level throughout the period.

January 31, 2008

2008-02-01T07:12:00.000-08:00

Whistler Avalanche conditions

January 31, 2008

Alpine: Considerable

Treeline: Moderate

Below Treeline: Moderate

Travel Advisory: A total of 43 cm of cold low density snow has fallen since Saturday, 15cm of which arrived during the past 24hrs. Strong South-Easterly winds accompanied last night’s snowfall. The low density surface layers of snow have been readily transported by the wind resulting in soft slab formation to the lee of ridge-tops and any terrain features in the high alpine up to 75cm in depth. In some areas the wind pressed surfaces from last week’s outflow winds are still very much in evidence. Keep in mind that large unpredictable avalanches are still very much a possibility, particularly if a cornice fall is involved.

Avalanche Activity: Explosive and ski testing carried out this morning resulted in widespread soft slab avalanche activity predominantly up to size 1.5 within the most recent storm snow layers. One non-ski compacted start zone ran to size two with the most recent windslab stepping down deeper to last weeks wind-hammered surface. The most recent activity on the Dec 04 Crust and facet layer was on January 21st and was initiated by a large cornice fall. New cornice tabs are soft and have been observed to be very fragile.

Snowpack: The snow that has fallen since last Saturday is overlying a variety of old hard surfaces that were created by last week’s strong NE winds and sun. Surface hoar up to 10mm in size formed last week at treeline and below on top of a layer of faceted snow. These layers are now buried by up to 45cm of loose and unconsolidated storm snow, and up to 75cm deep in the Powder Mtn region. In some locations in the vicinity of any creek beds these crystals are much larger and could provide a failure plane for future avalanche activity with additional loading. The December 4th raincrust and facet crystal weakness is well buried in most areas, and although it has gradually been gaining strength, it has continued to pop up sporadically. Its unpredictable and persistent nature has been problematic and backcountry travelers should continue to be cautious. The deep slab releases have generally appeared to initially fail in a shallow part of the slab in rocky start zones, propagating into the deeper areas.

Weather: Snow flurries today will taper off overnight, with a mix of cloud, sun and scattered flurries for tomorrow. The next organized system is expected to arrive onshore late in the day on Saturday, but the main energy of that system appears to be heading to the south of our region.

January 26, 2008

2008-01-27T07:02:00.001-08:00

Whistler Avalanche conditions

January 26, 2008

Alpine: Moderate

Treeline: Low

Below Treeline: Low

Travel Advisory: Widespread wind affected snow is the dominant surface in the alpine. The cool temperatures have begun to weaken the snow under the surface layers and some of the windslab may begin reacting more readily to skier traffic. Loose cold new snow is loading over these layers and will sluff easily in steeper terrain. Keep in mind that large unpredictable avalanches are still very much a possibility in isolated areas.

Avalanche Activity: The December 4th crust continues to react to large triggers like cornices. Falling cornice chunks could trigger a deep slab. The north winds have built areas of hollow hard slab into unusual locations that will remain a concern and may get weaker with the continued cool conditions through this week.

Snowpack: Cold wind loaded new snow will accumulate over the old surfaces through the weekend. You will find scoured areas, sastrugi, stiff windslabs, and some thin sun-crust on solar exposures. The snow below these surface layers has begun to weaken with the persistent cool conditions of the past few days. This process is going to continue to weaken the surface layers over the next several days. The December 4th raincrust and facet crystal weakness is well buried in most areas. Its unpredictable nature is problematic and backcountry travelers should remain cautious. This persistent weakness is expected to be with us for some time to come.

Weather: Windy, cold conditions with moderate snowfall will last through Sunday. An arctic airmass is going to continue to push cold but unstable air our way into next week. Expect conditions to be particularly bitter on Monday

January 24, 2008

2008-01-25T05:47:00.000-08:00

Whistler Avalanche conditions

January 24, 2008

Alpine: Low

Treeline: Low

Below Treeline: Low

Travel Advisory: Widespread wind affected snow is the dominant surface in the alpine. Most areas are quite stiff with isolated pockets of loose snow in sheltered pockets. Be wary of any hard hollow feeling areas of windslab, and keep in mind that large unpredictable avalanches are still very much a possibility in isolated areas.

Avalanche Activity: The December 4th crust continues to react to large triggers like cornices. Falling cornice chunks could trigger a deep slab. The north winds have built areas of hollow hard slab into unusual locations that will remain a concern and may get weaker with the continued cool conditions through this week.

Snowpack: The snowpack in the alpine is quite variable due to the strong winds accompanying the past storm. You will find scoured areas, sastrugi, stiff windslabs, and some thin sun-crust on solar exposures. The December 4th raincrust and facet crystal weakness is well buried in most areas, but the crust can still be found on the surface in some wind affected terrain. Although this buried weakness has gradually been gaining strength, it continues to pop up sporadically. The resulting avalanches are getting larger as the overlying snowpack grows. Its unpredictable nature is problematic and backcountry travelers should be cautious. The deep slab releases generally appear to be failing initially in a shallow part of the slab and propagating into the deeper areas. Rocky start zones seem to be a common factor in these larger events. This persistent weakness is expected to be with us for some time to come.

Weather: Cool and slightly unsettled conditions are expected to persist through the week with a weak system forecast for Saturday. Another arctic outbreak is coming early next week.

January 19, 2008

2008-01-19T08:31:00.001-08:00

Whistler Avalanche conditions

January 19, 2008

Alpine: Moderate

Treeline: Low

Below Treeline: Low

Travel Advisory: Monday’s storm cycle brought a total of 25cm of new snowfall accompanied by strong winds from the south east. Temperatures were mild but fell rapidly with its passage. There has been significant drifting at alpine and treeline elevations and the resulting slabs are quite stiff. Be wary of any hard hollow feeling areas of windslab, and keep in mind that large unpredictable avalanches are still very much a possibility in some isolated areas. A dusting of new snow has freshened up the old surfaces.

Avalanche Activity: Explosive testing on Tuesday produced results that were for the most part within the storm snow layers. Cornices have grown and were failing easily. Deep slab releases are continuing to occur sporadically with both large and small explosive triggers. One anomalous result was a size 3.5 with a fracture line up to 3.5m in depth produced with a 25kg charge. It ran on the December 4th crust and facet layer. Similar occurrences have been observed on Blackcomb and in the backcountry. There was also evidence of a fairly widespread natural avalanche cycle having occurred during the storm. You can expect to see lots of new cornice buildup – a falling cornice chunk could trigger a deep slab release in some isolated areas.

Snowpack: The snowpack over the alpine terrain is quite variable due to the strong winds accompanying the storm. You will find scouring, sastrugi, stiff windslabs, and some thin suncrust. All are now covered by a skiff of new snow. The storm snow layers are continuing to tighten, but some pockets of stiff windslab may still remain reactive to the weight of a person. The December 4th raincrust and facet crystal weakness is well buried in most areas, but the crust can still be found on the surface in some wind affected terrain. Although this buried weakness has gradually been gaining strength, it continues to pop up sporadically with the resulting avalanches getting larger and larger as the overlying snowpack grows. Its unpredictable nature is problematic and backcountry travelers should be cautious. The deep slab releases generally appear to be failing initially in a shallow part of the slab and propagating into the fatter part of the slope. Rocky start zones seem to be a common quality in these larger events. This persistent weakness is expected to be with us for some time to come.

Weather: Today’s flurries should taper by this afternoon and skies are expected to clear as a strong ridge of high pressure builds. Cool temperatures and clear skies are forecast to be with us into the middle part of next week.

January 17, 2008

2008-01-18T08:44:00.001-08:00

Whistler Avalanche conditions

January 17, 2008

Alpine: Moderate trending Considerable with exposure to the sun

Treeline: Low

Below Treeline: Low

Travel Advisory: Monday's storm cycle brought a total of 25cm of new snowfall accompanied by strong winds from the south east. Temperatures were mild but fell rapidly with its passage. There has been significant drifting at alpine and treeline elevations and the resulting slabs are quite stiff. You can expect that the alpine terrain has developed many new features. Be wary of any hard hollow feeling areas of windslab, and keep in mind that large unpredictable avalanches are still very much a possibility in some isolated areas.

Avalanche Activity: Explosive testing on Tuesday produced results predominantly up to size 1.5 within the storm snow layers. Cornices have grown and were failing easily. Deep slab releases are continuing to occur sporadically with both large and small explosive triggers. One anomalous result was a size 3.5 with a fracture line up to 3.5m in depth produced with a 25kg charge. It ran on the December 4th crust and facet layer. This occurrence corresponds with similar deep slab releases on Blackcomb on Monday, and periodically during the past week in various backcountry regions. There was evidence of a fairly widespread natural avalanche cycle having occurred during the storm. You can expect to see lots of new cornice buildup – a falling cornice chunk could trigger a deep slab releas on the underlying slope in some isolated areas.

Snowpack: The snowpack over the alpine terrain is quite variable due to the strong winds accompanying the storm. You can expect to encounter wind scoured areas, as well as areas of sustrugi and very stiff windslab. Temperatures fell dramatically after the passage of the storm which helped the storm snow layers to tighten in. Although we have not observed any natural avalanche activity since the temperatures fell with the storms passage, the stiff windslabs may still remain reactive to the weight of a person in some isolated areas. The December 4th raincrust and facet crystal weakness continues to get buried deeper, but the crust can still be found on the surface in some wind affected terrain. Although this buried weakness has gradually been gaining strength, it continues to pop up sporadically, with the resulting avalanches getting larger and larger as the overlying snowpack grows. Its unpredictable nature is problematic and backcountry travelers should be cautious. The deep slab releases generally appear to be failing initially in a shallow part of the slab and propagating into the fatter part of the slope. Rocky start zones seem to be a common quality in these larger events. This persistent weakness is expected to be with us for some time to come.

Weather: A series of weak systems to the North will brush by our region periodically over the next several days bringing a mix of sun, cloud, and a chance of scattered flurries. Temperatures will remain cool at lower elevations, with an inversion. A more organized system may arrive on Saturday.