25 Dec 2011
One whole cm recorded over night. Maximum temperature at 2260 meters was -3 at 18:00 Hrs Dec 24, and Max temperature of 0 at 1550 meters was at 0645 this morning. Freezing level stayed below the forecasted levels. With these strong zonal flows the weather models are not as accurate, off by 4-6 hours, or not even close.
Yesterday produced mostly size 1 avalanches with explosive and ski testing with a couple of size 2's on the larger start zones. Some areas remained closed due to the continuous redistribution of the snow over various surfaces.
Click here for the forecast and avalanche advisory: Weather Forecasat
24 Dec 2011
|Thanks to Darren Saul for contributing these images of a ski cut on the NE aspect of Vantage Peak in the Duffy Lake Region. The size 2 avalanche propagated from rock to rock, was 25 cm at the crown, the 30 by 50 meter slab ran about 300 meters.|
|Slab in motion|
|Shot of run out zone|
|Looking up the slide path|
|Toe of the avalanche. Forecasters have been talking about isolated wind slabs, here is a classic example. Luckily the party was very experienced, recognised the hazard and could perform an effective ski cut. Less experienced tourers may have been caught in the slide and with the amount of rocks evident in the slide path it would not have been pretty. As discussed in a previous post, once these pockets receive more load from the new snow arriving there will be many more of these events. Click here for the updated hazard rating: Avalanche Danger Advisory|
22 Dec 2011
|La Nina: Everyone was hope full that this winter would be a repeat of last winter. The fact of the matter is that there have been past La Nina years that are very dry! This could be one of those winters. Its still early yet and only time will tell if we get back into a good cycle of low pressure systems giving us what we really want! A toast to Ullr might be necessary. Click here to find out about Ullr: ULLR|
|Lenticular clouds moved in early this morning and then dissipated. The approaching front could finally be seen at the end of the day. The high pressure playing with our enthusiasm for snow and continuing to give us dry conditions. . For an explanation of lenticular clouds click here: Lenticular Clouds|
21 Dec 2011
In the avalanche community we use the term often when we describe the old loose facets around rocks or when a crust starts to break down and we refer to it as rotting. I am sure you have read the avalanche bulletins and the word rotten has come up on many postings.
So, when we have decomposing stellars with lots of skier traffic do we have rotten snow?
At 06:00 Hrs the temperature at the Horstman Hut was -13 with light winds. The ridge will break down again on Friday. The weather models are all trending to powder on Christmas Day.
20 Dec 2011
18 Dec 2011
|Not a lot of development in the Valley.|
|Thank you to Cliff Jennings for sharing these pictures of a cornice blast in Back Bowl on Whistler Mountain.|
17 Dec 2011
|Toni Sittlinger Photo: Earlier in the season we were talking about depth hoar. Here is an example. Not exactly weather today for developing depth hoar, warm temperatures in the alpine with strong winds. I asked what the avalanche conditions were today and was given a very descriptive term "Pasted pockets of wind slab". There are pockets of up to 30 cm of wind slab. For the updated avalanche advisory click here. Advisory|
|For a great read and if you are interested in improving your skiing check out this book written by Ken Chaddock. Click here for more info: Improve your skiing|
16 Dec 2011
15 Dec 2011
|This picture of the pump house at Horstman Creek was taken this time last year (Dec 15, 2010).|
|It is finally snowing, not much but enough to make the surface we so enjoy a tad softer. We received 6 cm over night at the Pig Alley weather plot. The next few days will give us snow showers to light snow. Every centimetre counts.|
14 Dec 2011
|The high pressure finally broke down yesterday allowing the first low into our area in a long time. Not much precipitation associated with the clouds but for now the high has been pushed to the south.|
|The grooming yesterday in Lakeside Area provided great skiing with 1 cm of new contributing to soft corduroy. Even a centimetre can help the snow quality.|
|Cliff Jennings photo of Mt. Neal on the Duffy lake Road taken yesterdeay. Very large slide with a crown line that is 3 weeks old. We have been in a draught!!|
13 Dec 2011
11 Dec 2011
|Hazard Acceptance Risk Tolerance Hazard Analysis Human Factors|
This individual is skiing a south west exposure at the end of the day in a shallow snow pack above a cliff band with no companion. The photographer is a fair distance away, patrol has long gone for the day. This individuals acceptance of exposure to potential hazards is very high.
In my career I have gone to many avalanche incidents where the individual has been badly injured or killed. Ironically most of those individuals had just completed their CAA Level 1 course. The new terminology is very important and everyone should pay attention. Play hard but be safe!!!
10 Dec 2011
|Not the best place to be!! Might have been an unpleasant ride into the rocks if it were just a bit bigger. From the photo think about this skiers decision making process. Will post my thoughts tomorrow. Perhaps some Kodak courage!|
|Nigel Stewart Photo: Taken up on the ice cap on Thursday December 8, 2011.|
|Nigel Stewart photos: Debris from the natural cycle we had November 22, 2011. Certainly tells the story about how much snow we have had in the past 16 days.|
|Amanda Taylor Photo: Surface Hoar from the Cerise Creek Trail. The perfect place for surface hoar development, no sun, surface temp -6 and a water source near by.|
8 Dec 2011
|Spatial Variability: I tried to look up this definition in the Websters Dictionary sitting on my office bookshelf. Published in 1988... no definition!! Today looking up the same term on Wickapedia: Spatial Variability occurs when a quantity that is measured at different spatial locations exhibits values that differ across the locations. This picture is older than my dictionary, the slope is just above the top station of Jersey Cream chair circa 1982. The road from 7 Th Heaven to the top of JC lift is now here. Who would have thunk! If you look up the definition on the Bilingual site of the CAA it is on page 211, scroll down, Click: Spatial Variability There is much to learn about avalanches and travelling in the back country certainly has its risks. Digging a pit and feeling confident about the slope should be one of many considerations. This definition is important!!|
|Jeff van Driel Photo and Observations. A pit displayed on the new App PitPod below:|
|The tests performed are the Compression test and the Propagation Saw test (PST) For an explanation of the compression test click here, scroll down: Compression test It will be listed in the glossary. The Propagation saw test is explained in this link: Propagation saw test|
6 Dec 2011
|Persistent Weak layers: This picture shows the formation of the December 4, 2007 crust which was very active, went to sleep, woke up went dormant and then woke up again on May 17 th and produced some very large Spring Time Avalanches. The temperatures went to + 17 degrees on that day and there were several large events in the Whistler Area. When this crust formed it rained to 2200 meters, the rain percolated down about 40 centimetres into the new snow and accumulated on a buried surface hoar layer. That winter was a prime example of a snow pack with a Persistent weak Layer. Click here to see the definition of PWL. Persistent weak Layers|
|This result occurred 163 days after the formation of the crust.|
5 Dec 2011
4 Dec 2011
|Present conditions are ideal to form surface hoar. In the past few weeks there has been much discussion on buried surface hoar layers. Click on this link to understand its formation. Surface Hoar|
3 Dec 2011
|For now the snow pack has tightened up and there appears to be significant bridging. The hazard rating is trending to Moderate. Click here for scale.Hazard Rating Read the description carefully. Skiers are unlikely to initiate a large avalanche but a snowmobile still has enough weight to possibly trigger the deep weak layers still present in the snowpack.|