Vanisle Avalanche Bulletin

Thursday 18 April, 2013

2013-04-18T08:28:00-07:00

It's spring time. That means it's the time when the Vancouver Island avalanche bulletin ceases three times weekly bulletins.

Many thanks to all the great sponsors who have kept this bulletin going. If you appreciate the bulletin then please go to our sponsors page and pass your appreciations on to these fine community members that make it possible. Many thanks also to the board of the Vancouver Island Avalanche Centre and to all who volunteer.

If you are interested in becoming a sponsor of the bulletin please contact us at forecaster@islandavalanchebulletin.com.

We will not issue further bulletins this spring unless we see a heightened hazard that compels us to issue an up date or warning. If you are planning spring trips do check back here to see if we have issued any updates or warnings and as always plan your trips carefully.

Below is some general advice for traveling in avalanche terrain at this time of year:

Spring avalanche danger patterns are generally quite predictable in that they relate largely to day time warming from rise in temperature and direct sun light. Danger is generally lower early in the day when temperatures are cool, the sun is not yet affecting slopes or cornices above, and a strong supportive melt-freeze crust exists. Danger increases as temperatures rise, solar radiation intensifies, and surface snow becomes wet or slushy. If wet snow does not freeze overnight or if it's raining, hazard can be up at any time of day.

Watch for snow becoming wet and slushy to more than about 5cm depth, pinwheeling, snowballing and small loose, wet snow point releases out of steep terrain and at rock outcrops. When you see these signs be prepared to change your planned route to a shadier aspect which has not yet melted or if that is not available stay out of avalanche terrain. Remember that wet snow avalanches can occur on lower angled slopes of 25 degrees or less.

Always keep an eye on what is above you. There are still many big cornices in the island mountains that are primed to fail as temperatures rise. These very heavy pieces of snow are a powerful hazard in their own right but they can also trigger an avalanche even if the place that you are lower on the slope feels cool at the time.

There is still snow in the forecast. When it does snow look for amounts of 20 to 30cm or more and be aware that this snow may not bond well initially to underlying crusts. Also watch for wind transporting new snow and creating slabs of greater depth in the lees and in cross loaded features.

While getting out early is generally the rule of thumb it is worth considering that the snow tends to be hard first thing in the day and that exposure on steep slopes could result in nasty falls on hard snow which could be especially dangerous if there are consequences below. Remember that terrain traps such as cliffs and trees are a danger not only in avalanches!

If you are tripping in the island alps this spring please send your observations to us at forecaster@islandavalanchebulletin.com.

The Canadian Avalanche Centre has some good general advice for travel at this time of year with links to educational tools if you go HERE.

Sunday April 14 2013

2013-04-13T21:34:00-07:00

Valid until: Tuesday April 16th 2013

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	Sunday	Monday	Tuesday
Alpine	CONSIDERABLE	MODERATE	MODERATE
Treeline	MODERATE	LOW	LOW
Below Treeline	LOW	LOW	LOW

Confidence: Good over all trend strong, again twice as much snow on the Western Mountains vs. the Northern or Eastern Peaks.

Past Weather: 11th 12th 13th April - Thursday - very light snow, cool all day and light South East to West. Friday - Some 5 cm to 15 accumulations. Some brisk wind from South West West or North West. Cool again below freezing. Saturday - Dry most places, with light winds variable South-West to North West a bit brisk and again cool.

Main Concerns: (Avalanche problems)

A Spring perspective: 'Spring avalanche danger rises and falls with the temperatures. If freezing temperatures occur over night things can stabilize or 'Recover'. If it does not refreeze the snow looses strength deeper and deeper making easy for a surface slough or deeper old layers to be triggered. Hanging Cornices and Snow Pillows in Steep Rocky Terrain can fail without warning and act as large triggers for avalanches on the slopes below. In the spring, at times like this, the snow is wet and dense and the Wet Loose slides can knock a person around even in small amounts.

Windslab - New Wind-slabs could form in this period with cooler temperatures snow and wind. Their distribution is West through North to East or anywhere else... at higher elevations as Re deposited snow transport is possible or may have already occurred. Old Wind slabs exist. Avalanches could be naturally triggered by rain high temperatures and or may be reactive to skiers. Avalanches to size 1.5 Destructive Scale are possible or large enough to injure or maybe kill a person. Some sliding layers could include smooth crusts and buried surface hoar.

New Snow - New snow at higher elevations and some preserved old snow sit over crusts. In the forecast period up to 12 cm of new snow may fall. Natural avalanche unlikely but human triggered possible on certain steeper slopes / aspects or sliding layers. Avalanche size small to Medium size 1 or large enough to injure a person. Some sliding layers could include smooth crusts Solar aspects and buried surface hoar Cool aspects. Watch for amounts over 15 cm.

Cornice Sun and rain and above freezing temperatures could destabilize Cornices. So far around here the Cornice failures have been mostly small but combined with terrain traps large enough to injure a person. In certain thin snowpack or thin-rocky terrain, rotted deeper snow layers are becoming more reactive too. Human triggering unlikely.

Weather Outlook:

Sunday - LIGHTENING forecast PM. Clouds and snow showers 6 - 10 cm snow. Winds 10 to 2o West South West. Freezing levels to 1000m falling over night to surface.

Monday - Clouds, snow flurries light amounts snow. Winds 10 to 20 from the West, North and East. Freezing levels to 1000m and cool over night.

Tuesday - Clearing some sun. Winds Moderate drop to light North North East. Freezing levels rising to 1500m lowering to 500m by eve.

Avalanche activity - Limited activity and reporting. Solar aspects a concern originating from rocky or thin snow pack areas worse at lower elevations... Some Glide cracks starting to show in steep terrain. Windslab somewhat reactive to testing.

Snowpack - New Wind Slab exists at higher elwevations and West to North aspects. A newer melt freeze crust is widespread at mid to high elevations, and in some areas faceting underneath. Recent snow fell on crusts with facets and perhaps surface hoar. Moderate somewhat sudden planar shears are more reactive on old/wet facets down 15 to 25 cm in those warm or thin areas. Watch for more than just new snow problems in two places: One in sunny aspects/or lower elevations and thinner snow-packs; as the thick crusts below the surface loose strength the old faceted layers under them may be willing to slide again, and the second place where old and new Wind Slabs or pillows sit at higher elevations on many aspects. These old and new Wind Slabs sit over the zippy (in some places) March 20 crust and could be reactivated.

Travel/Terrain Advise: "Test snow bridges and frozen lakes"

Sunday: Extra Caution in the Alpine due to new snow and wind. Don't stop or travel too much under large terrain, Cornices or steep rocky areas. Do not cut slopes above your friends. Expect variable snow surfaces; including crusts, moist snow. Extra Caution and avoiding steeper larger slopes, thin areas, cornices, and unsupported terrain. Slip and fall hazard may exist. Watch for winds creating redeposited wind slabs. Avoid COMPLEX terrain if it snow or blows much.

Monday: Watch for winds creating redeposited wind slabs. Extra Caution in the wind affected areas and in steeper terrain, thin rocky areas and unsupported terrain. Watch for overhead hazards. Slip and fall hazard may exist.

Tuesday: Watch for winds creating redeposited wind slabs. Caution in the wind affected areas and in steeper terrain, thin rocky areas and unsupported terrain. Watch for overhead hazards. Slip and fall hazard may exist. Watch Solar aspects and steep overhead terrain if sun is prolonged or temperatures make it to the teens.

Note: This may be one of the last detailed updates for the season; following this period we will run a generic spring message and provide updates if and when relevant. Good work people out there not getting injured too badly or killed in avalanches this season and providing good information and feedback. NW

Watch for updates to the bulletin, information on current conditions or observations on our Facebook page.

Prepared by: Niko Weis

Observations or comments? We want to hear them

Wednesday April 10 2013

2013-04-10T11:51:00-07:00

Valid until: Saturday April 13th 2013

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	Wed/Thursday	Friday	Saturday
Alpine	CONSIDERABLE	CONSIDERABLE	CONSIDERABLE
Treeline	MODERATE	MODERATE	CONSIDERABLE
Below Treeline	MODERATE	LOW	MODERATE

Confidence: Pretty good but really watch freezing levels especially if cooler and windier.

Past Weather: 8th 9th 10th April - Dry Monday with day time temperatures into the plus 4 or 12 if sunny. Mixed rain and snow Tuesday with better freezing levels than forecast some 5 cm accumulations. Tuesday eve storm drops 16 to 25 mm on the island and the storm lingers into Wednesday AM with 14 to 25 more mm rain or snow. Snow line at 4000 feet 1250 m Wednesday the front passed and the day dried out. Wind was a factor in the period high up. West to Northwest and switch to South East with last storm.

Main Concerns: (Avalanche problems)

Windslab - New Wind-slabs could form in this period with cooler temperatures snow and wind. Their distribution is hard to predict as winds are unusual, but South East through North or anywhere else... at higher elevations. Old Wind slabs exist at higher elevations in the Alpine and on Leeward and Cross-loaded terrain on North-West to North through East aspects. Avalanches could be naturally triggered by rain and or may be reactive to skiers. Avalanches to size 2 Destructive Scale are possible or large enough to injure or kill a person. New and old Wind-Slabs could combine to form a larger slide.

Storm Slab - Friday Saturday - New snow at higher elevations and some preserved old snow sit over crusts. In the forecast period up to 40 cm of new snow may fall. Natural avalanche unlikely but human triggered likely on certain steeper slopes / aspects at higher elevations. Avalanche size small to Medium size 2 or large enough to injure or kill a person.

Loose Wet / Wet Slab - (At lower elevations and Solar aspects): Sun and rain and above freezing temperatures could destabilize the snow surfaces or deeper layers. Wet or moist snow falls out of steeper terrain on most aspects lower elevations. Skiers may trigger or cut down moist snow on slopes over 35 degrees. Avalanches will be mostly small but combined with terrain traps large enough to injure a person. In certain thin snowpack or thin-rocky terrain, rotted deeper snow layers are becoming more reactive.

Weather Outlook:

Thursday - Clouds and sunny periods. Light flurry possible. Winds 10 to 2o plus North West. Freezing levels to 1500m falling over night to 1000m.

Friday - Clouds, snow mid day 15 to 25 cm by eve. Winds moderate from the Southeast then West. Freezing levels to 1000m.

Saturday - Snow continued in early AM 10 - 15 cm more possible. The day improves though and cools and maybe clearing. Winds Moderate to Strong gusts from the South- East and switching later to Northwest lighter North. Freezing levels 1000m lowering to 500m by day time.

Avalanche activity - Limited activity. Pinwheels. Solar aspects a concern originating from rocky or thin snow pack areas worse at lower elevations... Some Glide cracks starting to show in steep terrain. Limited observations.

Snowpack - A newer melt freeze crust is widespread at mid to high elevations, and in some areas faceting underneath. New snow may fall on crusts with facets and perhaps surface hoar may form Wednesday or Thursday eves. At lower elevations; sun rain and prolonged above freezing temperatures have destabilized the snow surface and loosened up deeper layers. Moderate somewhat sudden planar shears are more reactive on old/wet facets down 15 to 25 cm in those areas. Watch for more than just new snow problems in two places: One in sunny aspects and thinner snow-packs; as the thick crusts below the surface loose strength the old faceted layers under them may be willing to slide again, and the second place where old and new Wind Slabs or pillows sit at higher elevations on many aspects. These slabs sit over the zippy march 20 crust and could be reactivated by new Wind-Slabs or Humans.

Travel/Terrain Advise: "Test snow bridges and frozen lakes"

Wednesday/Thursday: Don't stop or travel too much under large terrain, Cornices or steep rocky areas. Do not cut slopes above your friends. Expect variable snow surfaces; including crusts, moist or wet slushy snow. Extra Caution and avoiding larger slopes, thin areas, cornices, and unsupported terrain. Slip and fall hazard may exist. Watch for winds creating redeposited wind slabs.

Friday Saturday: Friday - Good in Am perhaps, watch for winds creating redeposited wind slabs.. Later in day travel gets dicey in the Alpine due to high winds and snow. Saturday - Caution in the wind affected areas and in steeper terrain, thin rocky areas and unsupported terrain. Limit use to SIMPLE or Low end Challenging terrain until Sunday. Do not cut slopes above your friends. Caution Improving weather in the PM could lure you out while Storm slab and Wind -Slabs could be reactive. Extra caution is recommended in the Alpine and wind affected areas.

General for period: Avoid steep thin snow pack areas on rocky ground cover at lower elevations during sun or rain and in general.

Watch for updates to the bulletin, information on current conditions or observations on our Facebook page.

Prepared by: Niko Weis

Observations or comments? We want to hear them

Monday April 08 2013

2013-04-07T12:10:00-07:00

Valid until: Wednesday eve April 10th 2013

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	Monday	Tuesday	Wednesday
Alpine	MODERATE	CONSIDERABLE	CONSIDERABLE
Treeline	MODERATE	CONSIDERABLE	MODERATE
Below Treeline	MODERATE	MODERATE	MODERATE

Confidence: Good - The models agree although the North Island may have more rain / snow on Tuesday and higher winds than other areas.

Past Weather: The weather forecast was wrong for the period. We had light rain and or snow with less than half the expected amounts 43 mm West Coast 16 mm East and less on the North Isle. Temperatures cooler giving more snow than rain instead of heavy rain..Wind Light generally.

Main Concerns: (Avalanche problems)

Loose Wet / Wet Slab - Sun and rain and above freezing temperatures will destabilize the snow surfaces or deeper layers. Wet or moist snow falls out of steeper terrain on most aspects. Skiers can easily trigger or cut down moist snow on slopes over 35 degrees. Avalanches will be mostly small but combined with terrain traps large enough to injure a person. In certain thin thin-rocky rotted deeper snow layers are more reactive to human triggering. Monday Solar aspects and lower elevations Tuesday Wed AM all aspects and elevations.

Windslab - Old Wind slabs will be either added to with more snow or soaked with rain by later Tuesday. Higher elevations in the Alpine and on Leeward and Cross-loaded terrain on North-West to North through East aspects is where these old slabs exist. Avalanches could be naturally triggered by rain and may be reactive to skiers. Avalanches to size 2 Destructive Scale are possible or slides large enough to injure or kill a person.

Cornice - Sun, rain more snow and prolonged above freezing temperatures are destabilizing the snow Cornices and Snow Pillows in Steep Rocky terrain. Cornices are found in the wind affected areas at Treeline and Alpine elevations. Leeward aspects for Cornices are West through North to East. Natural Cornice failures are possible but random. Human triggering is Possible but still not that easy yet.... Avalanche size from small to more than large enough to injure or kill a person are possible. The worry here is that a ton or two of cornice may trigger a deeper old weak layer now more ready to release...

Weather Outlook:

Monday - Clouds and sunny periods. Dry. Winds light North-East. Freezing levels to 1500m during heat of day.

Tuesday - Snow mid day 1 to 2 cm changing to rain changing giving 15 to 25 mm. Winds moderate from the South- East. Freezing levels to 1500m up to 2000m plus over the day.

Wednesday - Rain continued in early AM 10 - 15 mm more, the day improves though and cools and maybe snow a bit could clear. Winds Moderate to Strong gusts from the South- East and switching later to North. Freezing levels 2000m lowering to 1300m to 800m by night time.

Avalanche activity - Limited activity. Pinwheels. Solar aspects a concern originating from rocky or thin snow pack areas worse at lower elevations; but could reactivate same thing at higher elevations with rain or prolonged sun.. Some Glide cracks starting to show in steep terrain.

Snowpack - A melt freeze crust is widespread at mid to high elevations. Sun rain and prolonged above freezing temperatures have destabilized the snow surface and loosened up deeper layers at lower elevations. Moderate somewhat sudden planar shears are more reactive on old/wet facets down 15 to 25 cm in those areas. Watch for more than just new snow problems in two places: One in sunny aspects and thinner snow-packs; as the thick crusts below the surface loose strength the old faceted layers under them may be willing to slide again, and the second place where old Wind Slabs or pillows sit at higher elevations on many aspects. These slabs sit over the zippy march 20 crust and could be reactivated as old wet wind slabs with rain.

Travel/Terrain Advise: "Test snow bridges and frozen lakes"

Monday: Don't stop or travel too much under large terrain Cornices or steep rocky areas. Do not cut slopes above your friends. Expect variable snow surfaces; including crusts, moist or wet slushy snow. Extra Caution and avoiding larger slopes, thin areas, cornices, and unsupported terrain. Slip and fall hazard may exist.

Tuesday: Travel not recommended in the Alpine due to high winds and rain. Caution in the wind affected areas and in steeper terrain, thin rocky areas and unsupported terrain. Avoid steep thin snow pack areas on rocky ground cover at lower elevations during sun or rain and in general. Don't stop or travel too much under large terrain Cornices or steep rocky areas. Do not cut slopes above your friends.

Wednesday- Early AM: Travel not recommended in the Alpine due to high winds and rain. Caution in the wind affected areas and in steeper terrain, thin rocky areas and unsupported terrain. Avoid steep thin snow pack areas on rocky ground cover at lower elevations during sun or rain and in general. Improving weather in the PM but hazards may be still lurking. Storm slab could be reactive. Extra caution is recommended in the Alpine due to prior rain. Caution in the wind affected areas and in steeper terrain.

Watch for updates to the bulletin, information on current conditions or observations on our Facebook page.

Prepared by: Niko Weis

Observations or comments? We want to hear them

Friday March 29 2013

2013-04-04T16:54:00-07:00

Valid until: Sunday eve April 7th 2013

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	Friday	Saturday	Sunday
Alpine	CONSIDERABLE	HIGH	CONSIDERABLE
Treeline	MODERATE	CONSIDERABLE	MODERATE
Below Treeline	MODERATE	MODERATE	MODERATE

Confidence: Fair - The models disagree on freezing levels and precipitation amounts.

Past Weather: The good weather ended and we had light rain and near freezing temperatures then above freezing for two days with sun cloud and light rain again..

Main Concerns: (Avalanche problems)

A Spring perspective: 'Spring avalanche danger rises and falls with the temperatures. If freezing temperatures occur over night things can stabilize or 'Recover'. If it does not refreeze the snow looses strength deeper and deeper making easy for a surface slough or deeper old layer to be triggered. Hanging Cornices and Snow Pillows in Steep Rocky Terrain can fail without warning and act as large triggers for avalanches on the slopes below. In the spring, at times like this, the snow is wet and dense and the Wet Loose slides can knock a person around even in small amounts.

Loose Wet (Friday mainly) - Rain and above freezing temperatures are destabilizing the snow surfaces. Wet or moist snow falls out of steeper terrain on most aspects. Skiers can easily trigger or cut down moist snow on slopes over 35 degrees. Avalanches will be mostly small but combined with terrain traps large enough to injure a person. In certain thin thin-rocky or wind loaded areas older slabs may become more reactive to human triggering.

Storm Slab - New snow is expected to start over night Friday as freezing levels lowers over the storm duration. 15 to 25 cm new snow is expected Saturday at higher elevations. Additional amounts to 0 to 10 cm for Sunday at elevations above 800m. Steeper slopes and most aspects will be loaded on a crust or slush. Natural avalanches are unlikely and human triggered likely on steeper slopes. Avalanche size small to large enough to injure a person.

Windslab - Wind and new snow should combine to build new Wind-slabs in the Alpine Saturday and into Sunday. Leeward and Cross-loaded terrain on North-West to North through East aspects will see loading. Avalanches should not be Naturally triggered but may be reactive to skiers. Avalanches to size 2 are possible or slides large enough to injure or kill a person.

Cornice - Rain more snow and prolonged above freezing temperatures are destabilizing the snow Cornices and Snow Pillows in Steep Rocky terrain. Cornices are found in the wind affected areas at Treeline and Alpine elevations. Leeward aspects for Cornices are West through North to East. Natural Cornice failures are possible but random. Human triggering is Possible but still not that easy yet.... Avalanche size from small to more than large enough to injure or kill a person are possible. The worry here is that a ton or two of cornice may trigger a deeper old weak layer now more ready to release...

Weather Outlook:

Friday - Clouds and showers giving 15 mm rain possible. Winds light and rising from the South-East. Freezing levels to 1500m.

Saturday - Lightening possible. Rain changing to snow giving 15 to 25 cm. Winds moderate from the South- East. Freezing levels to 1500m down to 1000m over the day.

Sunday - Snow or snow showers and clouds 0 to 10 cm. Winds Moderate dropping from the South- East and switching later to North. Freezing levels 1000m lowering to 800m Sun possible later in day.

Avalanche activity - Ski controlled slushalanches to size 1 plus were gaining size on way down. Random natural size 1 and 1.5 Wet Loose avalanches or wet sheet slides on Solar aspects originating from rocky areas or near trees were seen back 4 days..One or two old wind slabs a mid elevations steep ground West Facing mid way down slopes 5 days old. Some Glide cracks starting to show in steep terrain.

Snowpack - New snow will fall over the weekend on a wide variety of surfaces; Crusts, slush or wet snow. Sun rain and prolonged above freezing temperatures have destabilized the snow surface and loosened up deeper layers. Moderate somewhat sudden planar shears are more reactive on old/wet facets down 15 to 25 cm. Watch for more than just new snow problems in two places: One in sunny aspects and thinner snow-packs as the thick crusts below the surface loose strength old faceted layers may be willing to slide again, and the second place where old Wind Slabs or pillows sit at higher elevations on many aspects. These slabs sit over the zippy march 20 crust and could be reactivated as old wet wind slabs.

Travel/Terrain Advise: "Test snow bridges and frozen lakes"

Friday: Don't stop or travel too much under large terrain Cornices or steep rocky areas. Do not cut slopes above your friends. Expect variable snow surfaces; including crusts, moist or wet slushy snow. Extra Caution and avoiding larger slopes, thin areas, cornices, and unsupported terrain.

Saturday: Travel not recommended in the Alpine due to high winds and snow. Possibility of Lightening. Caution in the wind affected areas and in steeper terrain, thin areas and unsupported areas.

Sunday- Improving weather in the PM but hazards may be still building. Storm slab could be reactive. Extra caution is recommended in the Alpine due to high winds and snow. Caution in the wind affected areas and in steeper terrain.

Watch for updates to the bulletin, information on current conditions or observations on our Facebook page.

Prepared by: Niko Weis

Observations or comments? We want to hear them

Tuesday April 02 2013

2013-04-01T18:38:00-07:00

Valid until: Thursday April 4th 2013

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	Tuesday	Wednesday	Thursday
Alpine	MODERATE	LOW	MODERATE
Treeline	LOW	LOW	MODERATE
Below Treeline	LOW	LOW	LOW

Confidence: Fair - The precipitation amounts for the Western side of the island could be much higher than all other areas Thursday (85mm)

Past Weather: The Easter weekend was dry and warm with temeratures into the teens during the day and close to or above freeezing over night. Light winds throughout.

Main Concerns: (Avalanche problems)

A Spring persective: 'Spring avalanche danger rises and falls with the temperatures. If freezing temperatures occur over night things can stabilize or 'Recover'. If it does not refreeze the snow looses strength deeper and deeper making easy for a surface slough to be triggered. Hanging Cornices and Snow Pillows in Steep Rocky Terrain can fail without warning and act as large triggers for avalanches on the slopes below. In the spring, at times like this, the snow is wet and dense and the Wet Loose slides can knock a person around even in small amounts.

Loose Wet - Sun and prolonged above freezing temperatures are destabilizing the snow surfaces. Wet or moist snow falls out of steeper terrain on sunny aspects and skiers can esily trigger or cut down moist snow on slopes over 35 degrees. Avalanche will be mostly small but combined with terrain traps large enough to injure a person. In certain thin or wind loaded areas older slabs may become more reactive to human triggering (esp Sleds).

Cornice - Sun and prolonged above freezing temperatures are destabilizing the snow Cornices and Snow Pillows in Steep Rocky terrain. Cornices are found in the wind affected areas at Treeline and Alpine elevations. Leeward aspects for Cornices are West through Niorth to East. Natural Cornice failures are Probable but random. Human triggering is Possible. Avalanche size from small to more than large enough to injure or kill a person are possible. The worry here is that a ton or two of cornice may trigger a deeper old weak layer now more ready to release...

Weather Outlook:

Tuesday - Clouds and showers giving 5 mm possible. Winds light from the North to East. Freezing levels to 2000m down at night to 1500m

Wednesday - Sunny periods possible showers as well less than 1 mm. Winds light from the Northeast to East. Freezing levels to 1700m down at night to 1500m

Thursday - Rain showers and clouds 10 to 80 mm depending on location Western Island expecting much more. . Winds light from the South to East. Freezing levels to 15000m down at night to 1300m

Avalanche activity - Natural pin wheels and balling widespread on solar aspects. Ski triggered slushalanches to size 1 but not really gaining size on mostly the sunny aspects. Random natural size 1 and 1.5 Wet Loose avalanches or wet sheet slides on Solar aspects oringinating from rocky areas or near trees..On or two old wind slabs a mid elevations steep ground West Facing mid way down slopes. Some Glide cracks starting to show in steep terrain North aspects.

Snowpack - Sun and prolonged above freezing temperatures are destabilizing the snow surface and losening up deeper layers. Moderate sudden planar shear on old/wet facets down 15. Expect wet snow during the day on the sunny side and moist sorfter old snow on the shady sides. Watch for more than just slush problems in two places: One in sunny areas and thinner snowpacks as the thick crusts below the surface loose strength old faceted layers may be willing to slide again, and the second place where old Wind Slabs or pillows sit at higher elevations on many aspects. These slabs sit over the zippy march 20 crust and could be reactivated as old wet wind slabs.

Travel/Terrain Advise: Avoid the warmest part of the day. Avoid steep sunny slopes and corniced areas. Don't stop or travel too much under large terrain or steep rocky areas. Leave early, get out early if travelling. Do not cut slopes above your friends. Expect variable snow surfaces; including crusts, moist or wet slushy snow.

A slip and fall hazard is possible on slush or crusts and snow bridges and lakes should be well tested these days (Tennant Lake OK today)

Thursday- if rain amounts exceed 15 - 20 mm watch out a natural loose avalanche cycle may start

Watch for updates to the bulletin, information on current conditions or observations on ourFacebook page.

Prepared by: Niko Weis

Observations or comments? We want to hear them

Friday March 29 2013

2013-03-29T18:51:00-07:00

Valid until: Monday April 1st 2013

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	SATURDAY	SUNDAY	MONDAY
Alpine	MODERATE	MODERATE	MODERATE
Treeline	MODERATE	MODERATE	MODERATE
Below Treeline	LOW	LOW	LOW

Confidence: GOOD - 3 day forecast stable

Past Weather: Thursday and Friday were both dry and warm with temeratures into the teens in the sun, if it shone. The North and West were a bit more cloudy and clouds formed and winds were light on the Eastern Island later in the day.

Main Concerns: (Avalanche problems)

A Spring persective: 'Spring avalanche danger rises and falls with the temperatures. If freezing temperatures occur over night things can stabilize, but if they do not the snow looses strength deeper and deeper making one less step for an avalanche or surface slough to be triggered. Hanging Cornices and Snow Pillows in Steep Rocky Terrain can fail without warning and act as large triggers for avalanches on the slopes below. In the spring, at times like this, the snow is wet and dense and the Wet Loose slides can knock a person around even in small amounts.

Cornice - Sun and prolonged above freezing temperatures are destabilizing the snow Cornices and Snow Pillows in Steep Rocky terrain. Cornices are found in the wind affected areas at Treeline and Alpine elevations. Leeward aspects for Cornices are West through Niorth to East. Natural Cornice failures are Probable but random. Human triggering is Possible to Likley. Avalanche size from small to more than large enough to injure or kill a person are possible. The worry here is that a ton or two of cornice may trigger a deeper old weak layer now more ready to release...

Weather Outlook:

Saturday - Sunny dry and clouds possible. Winds light from the North to East. Freezing levels to 2200m down at night to 500m

Sunday - Sunny dry and clouds possible. Winds light from the Northeast to East. Freezing levels to 2700m down at night to 700m

Monday - Sunny dry and clouds possible. Winds light from the Northeast to East. Freezing levels to 2000m down at night to 700m

Avalanche activity - Natural pin wheels and balling widespread. Ski triggered slushalanches to size 1. on mostly the sunny sides. Random natural size 1 and 1.5 Wet Loose avalanches or wet sheet slides on Solar aspects.

Snowpack - Sun and prolonged above freezing temperatures are destabilizing the snow surface and losening up deeper layers. Expect wet snow during the day on the sunny side and moist sorfter old snow on the shady sides. Watch for more than just slush problems in two places: One in sunny areas and thinner snowpacks as the thick crusts below the surface loose strength old faceted layers may be willing to slide again, and the second place where old Wind Slabs or pillows sit at higher elevations on many aspects. These slabs sit over the zippy march 20 crust and could be reactivated as old wet wind slabs.

A slip and fall hazard is possible on slush or crusts and snow bridges and lakes should be well tested these days

Watch for updates to the bulletin, information on current conditions or observations on ourFacebook page.

Prepared by: Niko Weis

Observations or comments? We want to hear them

March 20,2013: 2 Skier involvement North Bowl above McKay Lake

Date Issued March 20, 2013 at 09:12PM

Size 2 Involvement above McKay Lake adjacent to the Mount Washington Ski Resort. Skiers were NOT inside the ski area boundary.

Report is a bit vague but essentially 2 skiers cut out a size 2 slab that released on the latest storm snow / ice crust interface. Surface hoar was reported present at the interface of these two layers. This was a treeline elevation feature on a North aspect, 45 degrees on the treed shoulder above McKay Lake that rolls into the cliffs. The slab was 10 meters wide and 30-40cms deep. This would be the latest storm snow from the past 48hrs. No injuries, but missing equipment.

The hazard today was High at Treeline and High in the Alpine.

cu.

Tuesday March 19, 2013

Date Issued March 18, 2013 at 09:54PM

Valid until 9pm Monday March 21 2013.

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	TUESDAY	WEDNESDAY	THURSDAY
Alpine	MODERATE	HIGH	HIGH
Treeline	MODERATE	HIGH	CONSIDERABLE
Below Treeline	LOW	MODERATE	MODERATE

Confidence: GOOD - WEATHER FORECASTS SEEM IN AGREEMENT OF APPROACHING FRONTAL SYSTEM

Past Weather: Light snow over the Island, 4-8cms. Freezing levels have been as low as 200m on Saturday night. Winds light - Moderate from the SW

Main Concerns: (Avalanche problems)

Storm Slab- A frontal system will hit the Island on Tuesday night bringing up to 40-50cms for the western side and 20-30cms of snow for the Eastern mountains. Wednesday morning will see new wind slab overlying a variety of surfaces. The 12th of march surface hoar layer will now be buried much deeper, especially in high alpine terrain and should be given healthy respect. Slabs will be possible to likely to trigger in the alpine and into treeline on all aspects over Tuesday and Wednesday due to switching winds. Avalanches up to size 2 - 2.5 are possible which is big enough to easily bury or injure a skier.

Weather Outlook:

Tuesday - Snow developing later in the day, winds moderate from the North, freezing levels 1100m

Wednesday - 20-50cms of new snow, the latter on the Western side. winds moderate to strong from the NW, freezing levels 1000m

Thursday - 10cms of new snow, winds dropping to moderate from the West, freezing levels 500m

Avalanche activity - Loose snow up to sz 1 on old hard surfaces

Snowpack

New snow will fall over the Island alps over the next 3 days adding another 20-50 cms of new snow onto the March 12 surface hoar layer. This layer is of concern in the high alpine mostly but be aware of it and keep an eye out around the treeline elevations. Watch for new wind slabs overlying this layer and for weakness within the new snow. The potential for step down avalanches from within the new snow down to the older interfaces does exist. Below this interface the snow pack is strong and well settled.

Travel/Terrain Advise:

The avalanche hazard will be High for two days in the alpine. Use extreme caution and avoid all avalanche terrain and the runout zones beneath. Keep a vary eye out for new slab development in wind loaded areas and remember that Northerly winds will reverse load many slopes that usually do not see wind loading.

Watch for updates to the bulletin, information on current conditions or observations on our Facebook page.

Prepared by: Cliff Umpleby

Observations or comments? We want to hear them

View older posts »

Friday 29 March, 2013.

2013-03-29T11:11:00-07:00

PLEASE NOTE:

The Island Avalanche Bulletin web site is having technical dificulty. Below are the current danger ratings. We will post a full bulletin as soon as the technical issues can be rectified. Thanks for your patience.

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	FRIDAY	SATURDAY	SUNDAY
Alpine	MODERATE	MODERATE	MODERATE
Treeline	MODERATE	MODERATE	MODERATE
Below Treeline	LOW	LOW	LOW

Friday March 29 2013

2013-03-29T10:59:00-07:00

Friday March 29 2013.

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	FRIDAY	SATURDAY	SUNDAY
Alpine	MODERATE	MODERATE	MODERATE
Treeline	MODERATE	MODERATE	MODERATE
Below Treeline	LOW	LOW	LOW

Confidence: GOOD - Weather Models stable

Past Weather: Dry and above freezing Thursday.

Main Concerns: (Avalanche problems)

LOOSE WET - Sun and continued above freezing temperatures are destabilizing the snow surface. This has been worse on Solar South and West facing aspects, but will now affect colder slopes which may not have shed their snow. All aspects and elevations are active but watch for the colder North aspects and higher areas. Avalanche Size, small but dense to large enough to injure a person.

CORNICE - SNOW PILLOWS - Sun and continued above freezing temperatures are destabilizing Cornices and areas snow in roack bandsngs of hang. Cornices are found at wind affected Treeline and Alpine elevations on West through North and East aspects. Natural Cornice falls are becoming more and more possible, while Humans are likely to knock at least part of one off.

Weather outlook -

Friday - Clouds give way to sunny. Dry and warm with light North winds. Freezing levels to 2000m/500m over night

Saturday - Sunny. Dry and warm with light North winds. Freezing levels to 2000m/500m over night

Sunday - Sunny. Dry and warm with light North East winds. Freezing levels to 2500m/1000m over night

Avalanche activity - Continued pin wheels and some natural size 1 loose wet slides from steeper Solar terrain. Some reports of Cornice collapses.

Snowpack -

Travel/Terrain Advise:

Watch lee zones for wind slabs within the new snow. In the alpine caution is advised with the potential to trigger deeper slabs over the latest buried weak layer.

Watch for updates to the bulletin, information on current conditions or observations on ourFacebook page.

Prepared by: Cliff Umpleby

Friday March 29 2013

2013-03-29T09:47:00-07:00

Friday March 29 2013.

Valid until March 31 2013

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	FRIDAY	SATURDAY	SUNDAY
Alpine	MODERATE	MODERATE	MODERATE
Treeline	MODERATE	MODERATE	MODERATE
Below Treeline	LOW	LOW	LOW

Confidence: GOOD - weather is very stable.

Past Weather: Thursday was dry and warm in all areas. Night time lows got to near freezing in some areas over 1300m.

Main Concerns: (Avalanche problems) Spring is here!

Loose Wet- Sun and well above freezing temperatures continue to destabilize the snow surface. Colder slopes have not yet shed the surface snow in all areas. Watch all aspects and elevations with day time warming and sun. Skiers may cut surface snow easily from slopes. Natural sloughs and up to size 1 avalanches are possible. These slides could knock a person down or over a cliff.

Cornice - Sun and well above freezing temperatures continue to destabilize Cornices and high angle snow pillows. Colder slopes have not yet shed the surface snow in all areas. Cornices are found in the wind affected Treeline and Alpine elevations and on leeward aspects North through East. Natural avalanches are possible anytime with lack of refreezing over night. A large cornice could be a problem but would be worse if it triggered a deeper layer and subsequent larger slide. Human triggering is likely. Expected avalanche size from small to more than large enough to injure or kill a person.

Weather Outlook:

Friday - Mainly sunny, winds light from the North. No new precipitation. Freezing levels to 2000m dropping to 500m over night.

Saturday - Mainly sunny, winds light from the North. No new precipitation. Freezing levels to 2000m dropping to 500m over night.

Sunday - Mainly sunny, winds light from the North East. No new precipitation. Freezing levels to 2500m dropping to 1000m over night.

Outlook for Monday more clear dry weather.

Avalanche activity - Continued pin wheels and size one naturals in steeper Solar terrain. Some cornice reports.

Snowpack

Spring conditions on most aspects and elevations. Crusts and slush abound! Colder slopes have not yet shed the surface snow in all areas. Old wind slabs still exist over the March crust. The two thick bridging crust layers from March and February have associated weaknesses which could produce a sliding layer if melted enough or hit with a large enough natural trigger. These two layers are down 50 to 150 cm. Step down avalanches are remotely possible at higher elevations with large triggers.

Travel/Terrain Advise:

Conditions will differ from night time to day time. Day time warming and sun will continue to destabilize the surface or in some areas deeper layers.

Travel early and get off steep large slopes before the heat peak of the day.

Stay out from under Cornices or areas with snow pillows hanging in rock bands.

Avoid large steep Solar slopes. Avoid gullies or channeled terrain.

Do not cut slopes above others and stop well away from gullies or channeled terrain.

Watch for updates to the bulletin, information on current conditions or observations on ourFacebook page.

Prepared by: Niko Weis

Observations or comments? We want to hear them

Thursday March 28th 2013

2013-03-27T23:25:00-07:00

Valid until: Saturday March 30th 2013. (10 PM)

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	THURSDAY	FRIDAY	SATURDAY
Alpine	CONSIDERABLE	MODERATE	CONSIDERABLE
Treeline	MODERATE	MODERATE	MODERATE
Below Treeline	LOW	LOW	LOW

Confidence: Fair - Double the wet rain snow for West side of island. Thursday Fri (11mm)

Past Weather: Not much snow since last weekend anywhere. Light snow or rain over Monday and Tuesday clearing Tuesday clear and warm Wednesday well over 10 degrees. No real wind since last weekend.

Main Concerns: (Avalanche problems)

'Spring is really here. Natural triggered avalanches from sun rain or prolonged above freezing temperatures create different challenges. Occasional Cornice or hanging slabs may drop triggering and starting larger slides in some cases. Crusts or slush on Solar aspects and loose wet snow on steeper slopes is to be expected.'.

Wet Loose - Rain, snow, sun and rising temperatures will make the surface weak and moist over the next few days. Skiers may cut or dislodge surface snow on Solar and other aspects at most elevations. Avalanches will be generally small but could be large enough to injure person in the right terrain. Natural slides are also possible from steep ground and higher elevations.

Cornice - Rain, snow, sun and rising temperatures will make Cornices loose strength. Cornices are found in the wind affected Treeline and Alpine elevations and generally hanging Northwest through East. Natural failures are possible; while human triggering is getting more likely. Avalanche size is small to large enough to kill or injure a person (if it is a large Cornice section or if it triggers a deeper layer and larger avalanche).

Wet Slab - Cornices or prolonged heat or surface avalanches may trigger older wind slab which site above one of two crusts. This is most likely in the higher elevations and on previously wind loaded aspects West North East South East in some places. Sledders or larger human triggers may also reactivate deeper layers.

Weather Outlook:

Thursday - Some rain or flurries, 3 cm to 11 cm, light South-ish winds and freezing levels 1600m to 1700m. Old wind slab -

Friday - Left over sowers or flurries will give way to clearing skies and High pressure. Winds light from the South East switching to Light North North West. Freezing levels to 1700m. (No over night freeze expected)

Saturday - Sunny Clear WARMING MORE. Winds light North North East. Freezing levels to 2200- 2900m!

Expect continued sun Sunday and on...

Avalanche activity - Surface sloughing and pin wheeling many aspects. Moist surface snow to size 1 with ski cut.

Snowpack

The surface snow is melt freeze crust or just melt at lower elevations and Solar aspects. Much surface disturbance has taken place by surface sloughing. Some cold snow is preserved higher up on colder aspects, this snow may have yet to slide. The March 20th crust is in some places on the surface and others buried under old snow or wind slabs, 20 to 50 cm down. The deeper crust from February will take a while to UN-bridge or re activate but if the warm weather keeps up...or a really large trigger hits it?!

Travel/Terrain Advise:

Over head hazards such as Cornice or Wet Loose slides may take place. Natural triggering or slides may take place. Stay out from under Cornices or steep slopes and larger terrain in full sun.

Slip and fall hazard may exist on crusts or slush.

Avoid the heat of the day, avoid thin snow packs and smooth rock ground cover.

Don't cut over down hill skiers and stop out of chutes or confined tracks.

Test the firmness of the crusts below with your pole, if the pole goes through old thick crust easily then get off slope.

Watch for updates to the bulletin, information on current conditions or observations on ourFacebook page.

Prepared by: Niko Weis

Observations or comments? We want to hear them

March 20,2013: 2 Skier involvement North Bowl above McKay Lake

Date Issued March 20, 2013 at 09:12PM

Size 2 Involvement above McKay Lake adjacent to the Mount Washington Ski Resort. Skiers were NOT inside the ski area boundary.

Monday March 25 2013

2013-03-25T00:05:00-07:00

Valid until: 11pm Wednesday March 27 2013.

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	MONDAY	TUESDAY	WEDNESDAY
Alpine	MODERATE	CONSIDERABLE	CONSIDERABLE
Treeline	MODERATE	MODERATE	LOW
Below Treeline	LOW	LOW	LOW

Confidence: Fair - Weather models disagree on rain/snow amounts + - 5 mm & watch the snow line!

Past Weather: The past 3 days was a dry period with only light snow to 4 cm. The temperatures were mostly below freezing except day time highs to 4 plus. The wind got up to a brisk 20 km dropped and rose to 20 km again; starting West North West and North and moved around to South East to South West.

Main Concerns: (Avalanche problems)

Wind Slab- Old re-deposited and fresher Wind Slabs lay over the March 20 surface hoar/ or crust facet layer or lighter snow/graupel weak layers. Many aspects are loaded at higher treeline and alpine elevations from the South East to North and North East with a cross loaded West. Triggering by skiing was likely over the last weekend and may be getting more stubborn now. Extra Caution should be exercised in the Wind Zone; it is possible to trigger avalanches down to the march 20th layer. Avalanches from pockets up to size 2 or just big enough to injure or kill a person are possible.

Wet Loose- Rising temperatures and rain or wet snow will soak the upper snowpack and new snow will be loose at middle to lower elevations all aspects, perhaps worse on colder aspects and much steeper ground. Natural surface activity is expected on steeper slopes and angles over 35 degrees will be reactive to ski cuts by later Monday on to Wednesday. Size 0.5 to 1.5 except in larger terrain and gullies perhaps large enough to inure a person..

Wet Slab- Rising temperatures and rain or wet snow may at first add to and then weaken/load the stiff older windslabs and near surface snow. Natural avalanche activity is possible and skier triggered avalanche also possible Monday PM and Tuesday especially in steeper terrain and at Tree line and Below. Size of avalanches small and up to just large enough to kill or injure a person if rain amounts are over 20 mm in the period. These slides have a chance of triggering down to a deeper layer at the highest elevations or with larger trigger.

Cornice- Possible during rain or wet snow event. North West through East aspects at and above Treeline. Triggering naturally is possible, human triggered likely Tuesday and Wednesday. Avalanches from small to Large enough to kill or injure a person if the Cornice triggers an old wind slab or deep instability at higher elevations.

Weather Outlook:

Monday - The day starts with snow up to 5 cm and by later in day breaks give way to rain up to Tree line, starting in the later; PM freezing levels from 200 m day time to 1500 m near end of day. Wind 10 to 15 km East South East.

Tuesday - The bulk of the rain or snow 10 to 20 mm or 20 cm at higher elevations above 4500' - 1300m. Winds lighter to brisk 20 km from the SE, freezing levels to 1500m

Wednesday - 5 to 10 mm rain or 7 cm snow possible towards end of day. Winds light to moderate from the SE, freezing levels 1500 m lowering to 1300m in the PM will bring snow levels lower.

Avalanche activity - Natural and ski triggered avalanches on Wednesday, no new last 24hours.

Snowpack- Spring means faster stability change: with sun becoming a player on Solar aspects. Longer days, fast temperature spikes; snow changes to rain and back to graupel pellets and then to snow and weird winds. Don't take it too lightly avalanche season is not over.

The latest new snow overlying the march 20th interface is settling out and gaining strength in Treeline areas but caution needs to be taken where winds have created stiff wind slabs over top of this layer. This layer is 30-40cms deep and could be much deeper in lee zones, ( 1 meter plus). Snow observations from the past 72 hours are reporting mod shears on this layer at treeline elevations.

The current surfaces are variable from light snow on higher or colder aspects and or new or old March 20 crusts or moist snow on the surface at lower elevations and Solar aspects. Surface hoar may have formed and remained in shady sheltered or higher elevations.

The rain events 10 days ago and the early February inversion have left two big thick bridging crusts 50 to 120 cm down. Between these crusts are moist or dry facets depending on elevation. The Feb 12 and March 20 layers could still be a player in the alpine in colder areas and thinner snow packs. With large triggers or rain the potential for a step down avalanche on this layer could be possible in specific terrain features at higher elevations.

Travel/Terrain Advise:

Monday - Caution in the Alpine and Wind affected areas. Normal Caution until rain starts then Extra Caution. Watch the Wind Zone for wind slabs within the new snow on many aspects. In the high Alpine caution is advised with the potential to trigger deeper slabs over the latest buried weak layer. This is more likely in colder steeper terrain.

Tuesday - Avoid Complex Alpine Terrain. Extra Caution as rising freezing levels, rain and or snow with some lighter wind are likely to destabilize the surface. Watch for over head hazards below steep ground or cornice areas. Some natural avalanches are possible with rain amounts over 15 mm. Loose surface snow will be reactive to skiers in steeper terrain. Higher elevations could be very different; watch freezing levels and if snow for any wind transport and accumulations.

Wednesday - Avoid Complex Alpine Terrain. Extra Caution continued with 1500 m freezing levels persisting and a bit more rain or snow possible. Watch for over head hazards below steep ground or cornice areas. Some natural avalanches are possible with rain amounts over 15 mm. Loose surface snow will be reactive to skiers in steeper terrain.

Watch for updates to the bulletin, information on current conditions or observations on ourFacebook page.

Prepared by: Niko Weis

Monday March 25 2013

2013-03-24T22:45:00-07:00

Valid until: 11pm Wednesday March 27 2013.

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	MONDAY	TUESDAY	WEDNESDAY
Alpine	MODERATE	CONSIDERABLE	CONSIDERABLE
Treeline	MODERATE	MODERATE	LOW
Below Treeline	LOW	LOW	LOW

Confidence: Fair - Weather models disagree on rain/snow amounts + - 5 mm & watch the snow line!

Main Concerns: (Avalanche problems)

Weather Outlook:

Tuesday - The bulk of the rain or snow 10 to 20 mm or 20 cm at higher elevations above 4500' - 1300m. Winds lighter to brisk 20 km from the SE, freezing levels to 1500m

Wednesday - 5 to 10 mm rain or 7 cm snow possible towards end of day. Winds light to moderate from the SE, freezing levels 1500 m lowering to 1300m in the PM will bring snow levels lower.

Avalanche activity - Natural and ski triggered avalanches on Wednesday, no new last 24hours.

Travel/Terrain Advise:

Watch for updates to the bulletin, information on current conditions or observations on ourFacebook page.

Prepared by: Niko Weis

Friday March 22, 2013

2013-03-22T18:37:00-07:00

Valid until 9pm Sunday March 24 2013.

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	FRIDAY	SATURDAY	SUNDAY
Alpine	CONSIDERABLE	CONSIDERABLE	MODERATE
Treeline	CONSIDERABLE	MODERATE	MODERATE
Below Treeline	LOW	LOW	LOW

Confidence: GOOD - Weather Models stable

Past Weather: 35cms new snow on Tuesday night: Light snow with some major squalls rolling through over the last couple of days.

Main Concerns: (Avalanche problems)

Storm Slab- 30-40 cms of new snow with wind effect now overlies the March 20 surface hoar/ facet layer. This layer has been reactive to skiing over the last couple of days. It will settle out at treeline elevations quickly. Areas that have been wind affected will be reactive to skiing and caution should be exercised in lee areas where wind slabs will overly this new instability. It is possible to trigger avalanches on the march 20th layer on Northern aspects at higher treeline and alpine elevations. Avalanches up to size 2 are possible.

Weather Outlook:

Friday - Mainly sunny, winds light from the SE. No new precip. Freezing levels to 700m

Saturday - Some light snow possible. Winds light to moderate from the SE, freezing levels to 900m

Sunday - 5cms of snow possible. Winds light to moderate from the SE, freezing levels to 1100m

Avalanche activity - Natural and ski triggered avalanches on Wednesday, no new last 24hours

Snowpack

The latest new snow overlying the march 20th interface is settling out and gaining strength in Treeline areas but caution needs to be taken where winds have created stiff wind slabs over top of this layer. This layer is 30-40cms deep and could be much deeper in lee zones. Snow observations from the past 24 hours are still reporting easy shears on this layer at treeline elevations. Cold alpine temperatures will help to preserve this layer.

20-30 cms Below the March 20 layer lays the march 12th interface that has been mostly eradicated at below treeline and treeline elevations but may still be a player in the alpine. The potential for step down avalanches on this layer could be possible in specific terrain features at higher elevations.

Travel/Terrain Advise:

Watch lee zones for wind slabs within the new snow. In the alpine caution is advised with the potential to trigger deeper slabs over the latest buried weak layer.

Watch for updates to the bulletin, information on current conditions or observations on ourFacebook page.

Prepared by: Cliff Umpleby

Observations or comments? We want to hear them

Tuesday March 19, 2013

2013-03-18T21:54:00-07:00

Valid until 9pm Monday March 21 2013.

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	TUESDAY	WEDNESDAY	THURSDAY
Alpine	MODERATE	HIGH	HIGH
Treeline	MODERATE	HIGH	CONSIDERABLE
Below Treeline	LOW	MODERATE	MODERATE

Confidence: GOOD - WEATHER FORECASTS SEEM IN AGREEMENT OF APPROACHING FRONTAL SYSTEM

Past Weather: Light snow over the Island, 4-8cms. Freezing levels have been as low as 200m on Saturday night. Winds light - Moderate from the SW

Main Concerns: (Avalanche problems)

Weather Outlook:

Tuesday - Snow developing later in the day, winds moderate from the North, freezing levels 1100m

Wednesday - 20-50cms of new snow, the latter on the Western side. winds moderate to strong from the NW, freezing levels 1000m

Thursday - 10cms of new snow, winds dropping to moderate from the West, freezing levels 500m

Avalanche activity - Loose snow up to sz 1 on old hard surfaces

Snowpack

Travel/Terrain Advise:

Watch for updates to the bulletin, information on current conditions or observations on our Facebook page.

Prepared by: Cliff Umpleby

Observations or comments? We want to hear them

March 16, 2013

2013-03-15T18:38:00-07:00

Valid until 9pm Monday March 18 2013.

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	SATURDAY	SUNDAY	MONDAY
Alpine	CONSIDERABLE	CONSIDERABLE	MODERATE
Treeline	CONSIDERABLE	CONSIDERABLE	MODERATE
Below Treeline	LOW	LOW	LOW

Confidence: Fair - Conflicting precipitation amounts

Past Weather: 20-45mm of precipitation fell in the Island mountains over the last 3 days. Much of this was in the way of rain at elevations, tree line and into the alpine due to high freezing levels. Winds have been fairly light out of the South.

Main Concerns: (Avalanche problems)

Wind Slab- A mixture of rain crust with soft slab overlying it will exist in areas at higher elevations where the recent rains did not reach. This soft slab is sitting on a variety of layers that will be reactive to ski traffic. Treeline elevations may have the same issue but freezing levels to above treeline may have helped stabilize this layer previously. Caution should still be taken at tree line elevations however as wind slab may still exist and will be reactive to skiing. New snow in the forecast will contribute to prolonged instability on these layers and with low freezing levels and strong winds forecasted soft slab overlying melt freeze or rain crusts at tree line elevations and higher are likely. Many areas at below treeline elevations are starting to become below threshold depths for avalanches.

Avalanches are possible to likely in alpine terrain on all aspects and could generate avalanches up to Sz 2 - 2.5 which is big enough to bury or injure a skier.

Weather Outlook:

Saturday - Freezing levels dropping to 800m, 5-10cms of new snow, moderate winds from the West

Sunday - Freezing levels 600m, 5-10cms of new snow, light to moderate West to South West winds

Monday - Freezing levels 400m, 10cms of new snow. Winds rising to strong from the SW

Avalanche activity - Some wet avalanches and signs of instability in moist snow over the last 48hours

Snowpack

Soft slab of varying depths now overlies a melt freeze crust that was buried on the 12th of March. This old surface consists of melt freeze crusts with surface hoar or facets overtop of it. Sun crusts widespread on solar aspects. This interface will continue to be reactive to skiing with varying results depending on depth of slabs. Freezing levels have been up and down all over the map over the last few days thus complicating the situation and creating variation in snow depths over the crust. Stability tests have been showing easy results on this layer.

Travel/Terrain Advise:

Caution is advised when dealing with this march 12th layer. Watch for soft slab in areas of larger accumulation and be aware that ski triggering will be easy in specific areas at treeline and into the alpine. Watch the lee zones where larger accumulations are lurking. There is a large variety in snow depths potentially out there so do not assume uniform depths as you increase in elevation especially when approaching areas lee to wind.

Watch for updates to the Bulletin, current observations or conditions on our facebook page

Prepared by: Cliff Umpleby

Observations or comments? We want to hear them

Wednesday March 13, 2013

2013-03-12T20:11:00-07:00

Valid until 9pm Tuesday March 12 2013.

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	Wednesday	Thursday	Friday
Alpine	HIGH	HIGH	CONSIDERABLE
Treeline	HIGH	HIGH	CONSIDERABLE
Below Treeline	MODERATE	MODERATE	MODERATE

Confidence: Fair - Weather forecasts are dubious

Past Weather: Up to 50mm of precipitation has been observed at TL elevations with more suspected at higher elevations and on the Western side of the Island. Freezing levels spiked on Monday night with alpine temperatures rising over zero for a few hours. Winds were strong from the SW then swinging around to the SE.

Main Concerns: (Avalanche problems)

Storm Snow \ Wind Slab- Large amounts of new snow now overlies a variety of hard surfaces. The interface between these surfaces varies from Sun crust, facets or surface hoar depending on aspect and exposure to the winds. Ski triggering on this layer is likely to possible on NE to NW aspects at tree line and above. Avalanches up to SZ 3 in alpine terrain are possible.

Wet Snow Avalanches - As freezing levels rise heavy rain fall will weaken the upper snow pack. Wet snow avalanches are possible on all aspects at treeline elevations into the alpine as the freezing levels spike to 1800m

Weather Outlook:

Wednesday - Rain and snow with freezing levels spiking to 1900m. Strong winds from the SW

Thursday - Rain and snow at higher elevations continues with up to 25mm possible. Strong SW winds. Freezing levels spiking to 1800

Friday - Freezing levels dropping to 1200m, Precipitation tapering off with possibly up to 10mm, Winds dropping to mod-light from the South-Southwest

Avalanche activity - Natural activity to size 2 at treeline elevations, NW aspects.

Snowpack

Up to 50cms of new snow now overlies our old hard surfaces. Shallower depths of 15-10cms on the Eastern side of the Island. This new snow is currently sitting on sun crusts on solar aspects and facets \ surface hoar in sheltered Northern aspects. This new snow is bonding poorly to the old surfaces and will be reactive to ski triggering over the next few days as accumulations continue. This instability will remain a problem due to the persistent nature of surface hoar and facets. At tree line elevations high freezing levels may improve conditions by rain soaking this layer where accumulations are shallower.

Travel/Terrain Advise:

Stay out of avalanche terrain when the hazard is high. Caution in avalanche run out zones should be taken as avalanches will run fast and far at higher elevations. Watch out for the wet snow and be cautious at treeline elevations as the rain soaks the snow pack. Rain soaked snow has no strength and is easily triggered once saturated. As the hazard drops make sure you know what you what you are dealing with under the new snow.

Prepared by: Cliff Umpleby

Observations or comments? We want to hear them

Sunday March10,2013

2013-03-09T17:23:00-08:00

Valid until 9pm Tuesday March 12 2013.

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	Sunday	Monday	Tuesday
Alpine	MODERATE	MODERATE	HIGH
Treeline	LOW	MODERATE	HIGH
Below Treeline	LOW	LOW	CONSIDERABLE

UPDATE: Larger amounts of forecasted precip in the last 24hours.

Confidence: Fair - Some conflicting precipitation models

Past Weather: Mix of sun and cloud with occasional flurries. Winds have been light and variable with little snow available to be moved around.

Main Concerns: (Avalanche problems)

Storm Slab - 50-100cms of new snow, larger accumulations on the west side will overly a variety of smooth surfaces. North facing terrain harbours surface hoar to 7mm (observed on Myra today) and new snow and soft slab will bond poorly to these interfaces. Expect ski triggering as Very likely to likely in alpine terrain on all aspects. Avalanches up to size 3-3.5 are possible. A natural avalanche cycle is expected in alpine terrain monday night into tuesday morning with natural avalanches running fast and far on the smooth interfaces up to size 3-3.5

Weather Outlook:

Sunday - Sunny becoming Cloudy, trace of new snow. Winds from the West. Freezing levels to 1300m

Monday - Mainly cloudy with 4-10cms of snow dependent on regions of the Island. Winds light from the SE. Freezing levels to 1100m

Tuesday - Monday night a pacific system will settle in with snow accumulations of 50-100cms of new snow dependent on island regions on tuesday. Higher accumulations are forecasted for the afternoon and into the evening. Freezing levels will spike to 1900m at the onset of the storm with strong SW winds associated with it.

Avalanche activity - No new observed.

Snowpack (UPDATED MONDAY MARCH 11)

New snow on Monday night will overly a multitude of hard surfaces at treeline and up into the Alpine. Melt freeze crusts were observed to the top of Mt. Myra today with surface hoar to 7mm overlying these hard surfaces. Although alpine winds will help dissipate surface hoar in wind affected areas there will be multiple sheltered areas where it will remain preserved. Expect a natural avalanche cycle on Monday night into Tuesday morning possibly with large accumulations of new snow. The onset of the storm brought mild temps with moderate to strong west winds. Cooler snow will bond poorly to many of the hard smooth surfaces out there and ski triggering will be likely in avalanche terrain.

Travel/Terrain Advise:

The avalanche hazard is high. Natural avalanches are expected. Stay out of avalanche terrain on Tuesday. Watch for natural avalanches running fast and far.

Prepared by: Cliff Umpleby

Observations or comments? We want to hear them

Thursday March 7, 2013

2013-03-06T20:15:00-08:00

Valid until 9pm Saturday March 09 2013.

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	Thursday	Friday	Saturday
Alpine	MODERATE	MODERATE	MODERATE
Treeline	LOW	LOW	LOW
Below Treeline	LOW	LOW	LOW

Confidence: Good - Trace precipitation and constant freezing levels

Past Weather: The last few days have seen a few cm's of new snow with light winds and freezing levels to 1400m. Night time recovery of the snowpack has been slow due to the higher freezing levels through the night also.

Main Concerns: (Avalanche problems)

Wind Slab - High elevation areas where the freezing levels stayed below zero have the potential to harbour lingering soft slabs. Mild temperatures will aid in the settlement of these but caution in areas lee to the wind should be taken. At tree line elevations there is a healthy melt freeze crust formed by rain when the pineapple express rolled over us on the weekend. New snow on this crust on direct north aspects is sloughing easily and was becoming moist today on solar aspects.

Triggering these slabs is possible in the alpine and unlikely at treeline on Northern aspects. Avalanche potential to sz 1-1.5

Weather Outlook:

Thursday - Sunny periods, Light winds from the southern quadrants and freezing levels to 1100m. Possibly a trace of snow.

Friday - Sunny periods, light winds from the Southern quadrants. Freezing levels 1000m

Saturday - Sunny periods, Light winds from the Southern quadrants. Freezing levels to 1100m

Avalanche activity - Some snowballing at lower elevations today. No new avalanches observed.

Snowpack

The pineapple express that rolled over us last weekend soaked the snowpack well into the alpine. This moisture, now frozen, has now left a hard frozen surface and also taken out some of the lingering surface weaknesses that were present.

2-5cms of new snow overlies this crust at TL and possibly more at higher elevations. This snow sloughs easily on steep north aspects On solar aspects it was bonding well and becoming moist today. In the wake of lowering freezing levels the crust is now firm on the surface at treeline and becomes breakable as elevation increases. Below this crust moist snow still exists up to 40cms deep at treeline elevations. As freezing levels remain constant, colder temps will penetrate deeper into the snowpack, helping to solidify the upper snow pack.

Travel/Terrain Advise:

Caution a slip and fall hazard may exist.

The hard surfaces at TL are making it hard to get a ski edge in. Be aware of fall hazard and where you may end up. With another couple of cm's of new snow sloughing in steep terrain should be considered. Although there is not enough mass to necessarily bury a person slough can take you places you may not want to go to! Dust off the ski crampons! Boot packing is firm and fast, ensure you are properly equipped when doing so on hard surfaces.

Caution is always advised at ridge top in respect to lee areas to the wind and where the snow pack is thinner than usual.

Prepared by: Cliff Umpleby

Observations or comments? We want to hear them

Monday March 04 2013

2013-03-03T22:12:00-08:00

Valid until Wednesday March 06 2013.

DANGER RATINGS (Make sure you understand the danger level meanings)

Outlook	Monday	Tuesday	Wednesday
Alpine	MODERATE	MODERATE	MODERATE
Treeline	LOW	LOW	LOW
Below Treeline	LOW	LOW	LOW

Confidence: Fair - The West Coast of Island may receive more snow than other areas Tuesday; and if it does the Danger could go to CONSIDERABLE in the Alpine. This is true if any area gets 20 cm or more of snow Tuesday. Note: Mt Cain has already had 5 cm snow since it rained last weekend.

Past Weather: On Friday and Saturday AM the Island Alps saw 20 mm rain on the East side and up to 50 mm rain over on the West Island. The wind was not really a factor. Freezing levels rose in most places to mountain tops before cooler temperatures set in later Saturday (this was more so on the West and North island). Temperatures rose well above freezing in the sun today (Sunday) on the East Island but remained below freezing under cloud in other areas.

Main Concerns: (Avalanche problems)

Wind Slab - The higher elevations in the West and North Island areas may have some wind slab forming with dry weather winds from the NW NE or Northerly directions, loading South South West and South East aspects in the Alpine. Human triggering is possible natural triggering unlikely. Avalanches could range from small to just large enough to bury, injure a person. Tuesday this Wind Slab may continue to build.

Weather Outlook:

Monday - Clear and cloudy periods with no real precipitation expected. Winds light gusting to moderate from the North North East. Freezing level Surface to 1000m.

Tuesday - Snow above 800 m, accumulations of 10 cm to 20 cm (West island). Winds light gusting to moderate from North North East. Freezing levels from 500m morning to 1000m with the snow fall in the day, then dropping to below 1000m by end of day.

Wednesday - Sunny periods are possible with a trace of snow too. Winds variable to light from North East to East. Freezing levels Surface rising to 1000m and dropping back to surface.

Avalanche activity - Numerous natural Pin Wheels and Skier Cut Loose Wet surface sluffs were reported on the East Island. Limited Alpine observations made.

Snowpack

A deep coastal snow pack has now undergone dramatic settling, compaction and surface renovations. The surface is a crust with moist snow below that is refreezing 60 cm down. Some areas have new snow on the crust. Watch for breakable crusts on colder aspects and higher elevations. My outlook for this early week; with two cold clear nights and showers this could deposit surface hoar and or light new snow over the crust, prior to Tuesday's snow fall.

Travel/Terrain Advise:

Caution a slip and fall hazard may exist.

It might be a good time to go climb. Watch for breakable crusts on colder aspects and higher elevations and variable surfaces. Re enter the Alpine with caution, confirm refreezing and bonding in the upper snowpack.

Monday - Watch for new Wind Slab in the Alpine which could be redeposited from North North West or Easterly Winds.

Tuesday and Wednesday - additional snow may be unstable on the crust and more Windslab may form.

Prepared by: Niko Weis.

Observations or comments? We want to hear them