10 Apr 2012

Even the winds from Sunday help to get cornices looking like this.                  R. Bougie Photo

At 2280 meters the temperature was 0, winds are 10-25 KPH from the ESE as of 06:00. At 1550 meters the temperature was +2, 70 % relative humidity, and the barometer is dropping slightly. No new snow, and in the valley it was 0.

For the Latest Avalanche Advisory click here: Avalanche Advisory

Speed kiting and ski cutting,  who would have thunk: Avalanche Control on the Fly

Urban Avalanche in Scotland: Roof Avalanche

Jeeps and Avalanches: Jeep Commercial




After the wild winds on Sunday thought I should bring up the topic of Anabatic and Katabatic Winds:




An anabatic wind, from the Greek anabatos, verbal of anabainein meaning moving upward, is a wind which blows up a steep slope or mountain side, driven by heating of the slope through insolation.[1][2] It is also known as an upslope flow. These winds typically occur during the daytime in calm sunny weather. A hill or mountain top will be radiatively warmed by the Sun which in turn heats the air just above it. Air at a similar altitude over an adjacentvalley or plain does not get warmed so much because of the greater distance to the ground below it. The effect may be enhanced if the lower lying ground is shaded by the mountain and so receives less heat.
The air over the hill top is now warmer than the air at a similar altitude around it and will rise through convection. This creates a lower pressure region into which the air at the bottom of the slope flows, causing the wind. It is common for the air rising from the tops of large mountains to reach a height where it cools adiabatically to below its dew point and forms cumulus clouds. These can then produce rain or even thunderstorms.[2]



katabatic wind, from the Greek word katabatikos meaning "going downhill", is the technical name for a drainage wind, a wind that carries high density air from a higher elevation down a slope under the force of gravity. Such winds are sometimes also called fall winds. Katabatic winds can rush down elevated slopes at hurricane speeds, but most are not that intense and many are on the order of 10 knots (18 km/h) or less.
Not all downslope winds are katabatic. For instance, winds such as the FoehnChinook or Bergwind, are rain shadow winds where air driven upslope on the windward side of a mountain range drops its moisture and descends leeward drier and warmer. Examples of true katabatic winds include the Bora (or Bura) in the Adriatic, the Bohemian Wind orBöhmwind in the Ore Mountains, the Mistral, the Santa Ana in southern California, the Tramontana and the Oroshi in Japan.

Yesterday I had mentioned the slide on Overlord, here is some information and pictures from Andre Charland. 






Date
2012-04-08
Location
11:50am
Location Description
Bottom of Overlord Glacier
Province
BC
Mountain Range
Coast Mountains
Coordinates

Elevation
1900m
Activity
Backcountry Skiing
Involvement
-
Injury
-
Fatality
-
Description
Skier traversed from flatter ridge heading skiers left into the middle of a moderate pitch convex slope that was wind loaded. A stiff slabbed release and the skier was able to ski out of it to the skiers right. It appeared to have released above the skier and step down a layer. Debris was large blocks up to 2m and very dense.


Date/timeSizeTypeTriggerElevationAspectSlab widthSlab thickness
2012-04-08 22:16 2SS1900w75m50cm 





Present TempMax TempMin Temp24hr TrendWind SpeedWind DirectionSky ConditionPrecipitation Type & Intensity
-5--RisingMECLRNone
Weather comment
Very strong winds the night before from the east.
Snowpack24hr SnowStorm SnowStorm Date
-070-
Snowpack comment
Wind pack, however was blower the day before in none sun affected aspects.



9 Apr 2012

Looking around the corridor there have been some large results from a few days ago.

At 2280 meters the temperature as of 06:00 hrs was -2. Winds were out of the SSE at 10-20 KPH.
At 1550 meters the temperature was 0, 62 % relative humidity and the barometer is falling slightly.
In the valley it is +1.

Report of a size 2 Sa in a gully feature on  Overlord Glacier around 12:00 yesterday. Three ski tourers doing the Spearhead. No involvement, not wide but stepped down so it was deep. Winds were certainly having their way with the snow yesterday. In places mother natures grooming was certainly evident with the wind transported snow.

For the latest Avalanche Advisory click here: Avalanche Advisory

Sledder near Alpine Wyoming gets lucky: Wet Slide

Dirt Bikes & Avalanches, What next? : Dirt Bike in an Avalanche

Snowmobile doing cornice control: Close Call

Falling off a cornice: Walking on a cornice?

And yet another person falling off a cornice and into an avalanche: Going Down

Update on Avalanche in Kashmir: 139 Now presumed buried

The cornices in our area are huge, its wise to stay away from them!!


Wet snow avalanche.


8 Apr 2012


Overview of slide North of Mt Fee from yesterdays post. Avalanche occurred April 6, 2012.

At 2280 meters the temperature is - 7, winds were 25-45 KPH from the E as of 06:00. At 1550 meters the temperature is -5, 73 % relative humidity and the barometer is declining slightly. In the valley it is -1.

Surface Hoar from April 7, 2012, developing in protected areas.


For the updated Avalanche Advisory click here: Avalanche Advisory

What it would be like being hit by a small avalanche from behind: Dry And Fast

Nothing like being dug out quickly: Short Clip

135 Missing after avalanche in the Pakistan\India Border: There is a lot of snow

Another report with some history of the area: Siachen Glacier

Some information on the ACMG blog: Spearhead

More avalanche news from Europe: Austria


Some photos from Braden Douglas from Decker Yesterday:

Huge Cornice
Natural on Decker- ran shortly after storm sz 2.5
-Decker shoulder- ran during storm all the way down to decker meadows sz 3
-SW side unsupported rocks- recent



Very Large Cornice

Storm slide off Decker form last week

Old Fracture Line

Recent Slab Avalanche in the Rocks


Some news from the Duffy :
NW, NE, N slopes skiing well to about 1600m.  Corn on true S slopes starting around 2-3pm or so.



Some natural releases on E slopes - probably solar : From Lee Lau







If you have not had the time to do it yet, please fill in the Spearhead Hutt Survey, click on this to get to it: Spearhead Huts

7 Apr 2012


Not the best place to ski cut or board, certainly hard to High Mark?? April 6, 2012

At 2280 meters the temperature was -10, winds were 5-15 KPH from the E, as of 06:00.
At 1550 meters the temperature was - 8, 89 % relative humidity and the barometer is steady.
In the valley it is -4. No new snow over night.

Some Na size 1-2 avalanches on solar aspects, some isolated Sa on very steep terrain like this example.
Not much activity considering the temperature.

For the latest Avalanche Advisory click here: Avalanche Advisory

Snow boarder pops his Snowpulse: Going Down

Snowmobiling in Norway, not fast enough: Fast moving slide

Took a lot of effort to get there!!

Size 2.5 just north of Mt. Fee snowmobile access skiing or snowboarding release. Wow no one dead!! April 6 2012. Slide ran over there snowmobile tracks. NW aspect.


Epic just getting to where the trigger point is!!

Access point, lots of sleds involved in this adventure.

How strong is the sun this time of year. Picture below was taken in the valley at 08:00 East facing slope, air temperature -5.


6 Apr 2012


New snow, solar aspects, strong sun = Avalanches


At 2280 meters the temperature was - 11 as of 06:00. The winds were 0-5 KPH from the SSW. At 1550 meters the temperature was -8, 92 % relative humidity and the the barometer is rising. In the valley it was
 - 5. No new snow over night.

Good settlement and tightening in the snow, but the cornices are still large, crust on all solar aspects, and surface hoar is developing on sheltered north facing slopes.

For the updated Avalanche Advisory click here: Avalanche Advisory

What it would be like getting caught in a wet slide: Sierra Spring POW

Interesting study out of Switzerland on burial statistics: Time is a factor

Ski Touring in Alaska, big country, big rides: Talkeetnas

If you go out on the Spearhead be diligent and fill in this survey: Hut Survey

Some more information on tree wells:

Treewell Safety
NARSID stands for Non-Avalanche Related Snow Immersion Death. NARSID incidents occur with deep snow or tree well immersions, in which a rider or skier falls into an area of deep, unconsolidated snow and becomes immobilized. The more the person struggles, the more entrapped in the snow they become, and risk suffocation.
     • Each skier or snowboarder controls his or her own level of risk and are the only ones that can prevent this type of accident from happening. Always ski and ride with a partner. To minimize your risk, you must know how to travel safely with your partners in these un-groomed deep snow areas
     • Always stay in visual contact so that your partner(s) can see you if you fall. Visual contact means stopping and watching your partner descend at all times, then proceeding downhill while he or she watches you at all times. It does no good if your partner is already waiting for you in lift line while you are still descending the slope;
    • Stay close enough to either pull or dig out. If you have any question about what "close enough" to assist someone in a tree well is, hold your breath while you are reading this. The amount of time before you need air may be how much time your partner has to pull or dig you out of danger. Other factors such as creating an air pocket or the position you fall in, may affect this critical timeframe.
    • Remember, if you lose visual contact with your partner you could lose your friend. It is important to know that most people who have died in deep snow or tree well accidents had been skiing or riding with "partners" at the time of their accident. Unfortunately, none of these partners were in visual contact so they were not able to be of help in a timely manner.



A dedicated site to tree well & deep snow issues: Tree Well & Deep Snow Safety

Posted this video already this year, but here it is again: Tree Well Rescue


Fresh off the Press


Grizzly lake today! Sledder got stuck on hill, buddy drives over top of him and cuts the slide. Stuck guy was taken about 60m Thanks to Peter Norie for the information. April 5, 2012



Same location as fatality last month.


I watched it happen from the other side of the valley. Victim drives right up the slope and gets stuck. You can see his track on the left into the slide area. His riding partner goes up the back side and descends down the hill towards him. The slide let go before the upper sledder reached the future fracture line. We watched it all go down in complete amazement that more people don't die in the backcountry doing what these two did!

5 Apr 2012

One of several size 2.5 avalanches from explosive control on Blackcomb yesterday. The slide path referred to as Rock Shot 1 ran into the Hour Glass releasing it, then running out to the lake in Ziggy's Meadow.

At 2280 meters as of 06:00 the temperature was -10, winds were 10-20 KPH from the NNE. At 1550 meters the temperature was -7.5, 95 % relative humidity, and the barometer os on the rise. No new snow over night. In the valley it is -2.

Field observations from yesterday in the corridor, natural avalanches from size 1-3 during the storm, natural activity in the am up to size 2.5 and natural size 2 on solar aspects in the pm.

Did anyone get pictures of the slides in the Spearhead yesterday??

For the updated Avalanche Advisory click here: Avalanche Advisory

Sad to report a tree well tragedy: Snow Boarder found in tree well

Large avalanches near Elkford B.C. : Smith Basin




Another result from explosive control on a path referred to as Tifosi.

4 Apr 2012

Unsettled weather for a few days, hopefully the new snow gets a chance to settle out.

At 2280 meters the temperature was - 12 as of 06:00. Winds were 0-10 KPH from the SE. At 1550 meters the temperature was -9, 95 % relative humidity, and the barometer is on the rise. At that elevation 7 cm of new was recorded, and 8 cm at pig alley. In the valley it is -2.

Natural avalanches (Na), Skier Accidental (Sa), Explosives (Xe), Ski Cutting (Sc) from size 1-3 recorded in the corridor yesterday. Some activity was stepping down into the March 27 th interface.

Yesterday 22 cm was recorded at pig alley during the day, for a 24 hr total of 62 cm. Not bad for an April Storm. A size 3 slide was initiated with explosives on the hanging roll yesterday.

It is unfortunate that people are still disobeying avalanche closures and skinning into areas where potential avalanche control could be initiated. Just because the alpine is closed does not mean that at some point of time in the day the Ski Patrol will not try to test or control slopes when they are able. Control work is essential to protect machinery which is used at night to keep the mountain opened for our skiing pleasure.
Use your brain and go touring some where else.


For the latest Avalanche Advisory click here: Avalanche Advisory

Creating an avalanche, jumping off a cliff then filming it from the air: Air Borne Avalanche

Knocked down by a size 1: Pole Cam

Spearhead Hut Survey, click here: Hut Survey


Just a little wind effect.

3 Apr 2012

Traverse into Disease Ridge popped out slide Sunday.

You can see the first traverse into the chute where we backed off and
decided to go in higher and ski cut. The fracture line sort of lines up with
the lower traverse line, so it appears that that was where the fracture
occurred, but it wasn't. It was a good a wakeup call for us to see the snow
slide well beyond the flats and continue to travel uphill onto the moraine
at the bottom. 








At 2280 meters as of 06:00 hrs the temperature is -5, winds are 75-100 KPH from the SSE.  At 1550 meters the temperature is - 2, 99 % relative humidity, and the barometer is dropping.  At that elevation 23 cm of snow fell over night. At Pig Alley 40 cm was recorded. In the valley it is
 +1. 


 Size 1-1.5 SSL were reported yesterday where people could get to.  


Yesterday afternoon a gust of 125 KPH was recorded at the Horstman Hut at 15:30. Over night the Max gust was recorded at 117 KPH at 02:30.


For the updated avalanche advisory click here: Avalanche Advisory

Another avalanche fatality in Colorado: March 30

Snowboarder gets caught in large avalanche: Engulfed

When and where will there be flooding: Snowpack Science

Scary ride in Canmore: Avalanche


2 Apr 2012

Amazing tree skiing yesterday, even the kids were happy with the foolish amounts of snow.

At 2280 meters the temperature was -8 as of 06:00 hrs. Winds were 45-65 KPH from the S. At 1550 meters the temperature was -5, 99 % relative humidity, the barometer is dropping. At cat skinner weather plot 1 cm of new snow was recorded, at 1650 meters on Whistler 1 cm of new snow was recorded as of 05:30.  In the valley it is -0. Mother nature certainly had a different outlook than the forecast from yesterday!!!  The storm is still on its way with less snowfall than expected but the winds will certainly pick up as the storm moves in.

For the updated avalanche advisory click here: Avalanche Advisory

Winter has returned but when the sun does come out it is very strong, same strength as it would have in September. Cornices are still an issue as all this new snow helps them grow, several stories in the past week about cornice encounters, be aware. Here is a clip of a cornice failing on Whistler Mountain last week: Piccolo

Avalanche control in Switzerland, they have some cool toys: Rocket Launcher

Switzerland has some amazing terrain, Andermatt is one location where they are spending as much money as the Jumbo developers to create a resort like WhistlerBlackcomb, here is a great clip of some free ride skiing in that area: Good Footage


Not much information but there was an Avalanche at Panorama resort yesterday: Panorama

Using kids addition 391 cm of snow fell at 1550 meters at the Catskinner plot March 2012


The popcorn at the alpine shop was especially good!! Good incentive for child labour.

1 Apr 2012

Sasquatch seen carrying injured ski tourer on Rainbow Mountain.

At 2280 meters the temperature was - 8, winds were 20-30 KPH from the SSE as of 06:00. At 1550 meters the temperature was - 5, 97% relative humidity, and the barometer was on the rise. At that elevation 13 cm fell over night and 11 cm fell at Pig alley. In the valley it is 0.

March was amazing, just over 5 m of total snow for the month, depending where you are in the corridor. Now that April is here it does not want to quit, further  possible accumulations of around 75 cm by Tuesday Morning.

Yesterday in the corridor numerous size 1-2.5 avalanches occurred, bigger occurrences were in the Duffy area.

For the updated avalanche advisory click here: Avalanche Advisory

Wet snow slide at Bridger: Bridger Bowl

Guess this guy was ok, how many of these do we not hear about: Whistler Backcountry



Big Back Flip

Summary from Steep Creek

  • Valentine days surface hoar pwl is still active.
  • Can be triggered off shallow rocky start zones
  • To illustrate variability;  in ridge on the background, on slopes of similar N aspect with similar slope angles, cornice drops resulted in nil results.
Trigger stood in a convenient location to capture the skier about to drop into mini-Heartstrings. As he made the last step down to the shooting platform, the entire slope depicted failed to ground, carrying trees and stripping boulders and washing them downslope. The shooting cracks show that the failure initiated on Trigger's last step. The marks at picture top are where the skier crawled on his belly while thinking light thoughts and grovelled back to the "safe zone" where Trigger is standing.

The rocks in the near foreground used to be covered in snow but are obviously now uncovered. They are a classic shallow rocky start zone. None of us were terribly interested in a closer look at the aftermath but our suspicions are failure on the V-Day layer


Slope is N facing slope about 38 - 40 deg steep at 2100 m at location in Central Duffey.   
We found that the slide had zippered down from Trigger's shooting platform, had grown in size and further ripped to ground downslope entraining our skintrack and depositing rather large blocks of snow, uprooted trees and various size boulders on what was once perfectly good powder. It looks like this sympathetic release had crown sizes of between 1.5 to 2m. It too failed on the V-day layer (decomposing surface hoar of approx 1mm grains)




Taken from across the valley looking SE towards the slope in question


Other observations from the Rutherford Area
Thanks Erik
Yesterdays action Wayne
>
> Crowns down 20-60 cm, 50-200m wide, 50-200m long, east to west including north aspect start zones. Most start zones had a crust and some stiffness in the snow on that crust, suspect had small surface hoar on cr. To make it such a widespread weakness. Start zones were convex rolls at least 40 degrees. Na, sz 2-2.5 in Rutherford


>