Another Big Storm?

While it’s still a few days away, and therefore subject to change, one of our weather forecasting services has said that all the various elements are coming together for a  major storm to sweep across BC and into the southern and central Rockies Friday night and most of Saturday. You may have heard the forecasts warning of frighteningly cold temperatures arriving this weekend. Well, this now seems to be a certainty, but the cold arctic air that is on its way to freeze us out of house and home will first collide with a moist flow coming in from the Pacific ocean, resulting in this storm.

The only question that remains is: will we have to wait until the cold snap is over before we venture out onto the mountain? We’ll let the -30 temperatures answer that one!

A Morning on Avalanche Control

As those who have been here over the past few days know,  Lake Louise is enjoying great skiing conditions, thanks to the recent storm and the relative lack of wind accompanying it. No wind means that the snow gets evenly distributed over the terrain, and remains soft and fluffy.

The wind picked up yesterday, however, and kept up through the night and into today with gusts at reaching 50-60km an hour. With lots of snow available to be blown around (called fetch), things can change dramatically in a short time, depending on how hard and from which direction the wind is blowing. This recent wind came from the south-west, and since this is where pretty much all of our wind comes from, the wind-loading that occurred as a result followed fairly predictable patterns. 

The avalanche forecaster usually arrives at the Snow Safety office by6:30am, and begins the process of gathering weather information from a number of sources in order to produce a plan of attack for the day’s avalanche control. From our automated weather stations, we can see a detailed record of what happened since the resort closed the previous day. The stations record snowfall, wind speed and direction, temperatures, and moisture content of the snow, among other things. With this knowledge, the control teams head out the door and up the mountain, having a good idea in their heads of what they’ll see when they get there, but still careful to travel cautiously, since while a weather station can give a good general picture of the weather, complicated and varying terrain have their way of affecting the weather around them, and one should always be ready to experience the unexpected.

My control team headed out the door with the plan to control the front side of Summit, then Whitehorn I, and then over into Whitehorn II. On the front side of Summit, there aren’t a lot of places of concern, but the few that are there still need the same attention we pay to everywhere else. For Whitehorn I, we travelled down the fence line on skier’s right, since that is where the cornice usually forms, and a large part of avalanche control is making sure cornices don’t have the chance to grow too large. The newly-deposited snow was between 15-25cm in isolated spots, and only somewhat showed signs of slab. Our ski cuts produced few results, and the sow appeared to be bonding well to the underlying layer.

After these runs were opened, we moved on to Whitehorn II – D, E, and F Gullies in particular. We had a bunch of explosive charges, and planned to place them on both sides just below the tops of the gullies, where they roll over into their steepest pitches. These ‘convexities’ in the slope are the usual suspects when it comes to avalanche trigger points, and are most likely to produce results when explosives are used. In D Gully, it was hard to tell exactly what kind of result we got since the light was poor, but we could still see the powder cloud that signifies the advancing edge of avalanching snow. Into E Gully, we used a similar placement for the charges, and the photo below shows the bombs as they’re thrown onto the slope below:

Hand charges thrown into E Gully

One shot landed and stuck in the snow, right where it was meant to be. The other shot landed on hard snow and started to slide down the slope, stopping in the narrowest part of the choke, 150m below where it was supposed to be. The choke didn’t have much snow, so we weren’t expecting the shot to produce any significant results. After a wait of 2.5 minutes (length of the fuse), the bomb that had slid downhill went off. It started an avalanche in its immediate area, but as the snow started to slide away, the snow above became unsupported from below and began to go as well, piece by piece, until eventually the snow in which the other charge was sitting began to slide as well. Our hearts sank as we realised that the second shot might be moved away from where it would have the most impact, but just as quickly as the slide began the shot went off, increasing the size of the already moving avalanche. We watched with amazement as almost the entire gully was completely cleared of snow, and a few boulders as well. The poor light didn’t permit any photos of the avalanche, but if you’re up skiing Boomerang or Brownshirt in the next few days, look up into Whitehorn II – you can’t miss it!

Big Storm Ends

Arrived at work early Monday morning to see the final tally of this weekend’s storm, and our backside weather plot has recorded 29cm since Saturday morning. The excellent conditions we have now will only get better if the snow that is forecast to fall throughout this coming week actually arrives! A quick look around the internet at various other western North American ski resorts shows that most are still anxiously awaiting snow, so even after a bit of a dry start for us, we feel fortunate to have such great skiing. Get out there and enjoy the powder!

New Ptarmigan Chairlift at Lake Louise

After a long process of planning, approval, and construction, the brand-new Ptarmigan chair is poised to open to the public in the next few days. This Leitner-Poma fixed-grip quad replaces the older lift of the same name, and will have the same uphill capacity. The unload is in the exact same spot, but the base station has been moved about 5m to the right as you face uphill in order to keep the lift line further away from the forest edge  that makes up one side of Exhibition. While the old lift had its drive station at the bottom, this new one has its at the top, which, combined with more modern technology, will result in a reduction of energy required to run the lift.

From start to finish, the fact that Lake Louise is located in a national park governs how any project proceeds, if at all. Since the Ptarmigan chair replacement is what is considered a “like-for-like” construction project, the approval process is less arduous than a proposal for, say, a new lift in an entirely new location. Like-for-like in this case means that what is being built is going in the same place as what is being replaced, with no change in uphill capacity, and little to no terrain modification, deforesting, etc. Any project that does not fall into the like-for-like classification must be included in the long-range plans currently being drafted by the Banff and Jasper ski areas, and are subject to a more intensive review and approval process. Like anything, there are exceptions to the rules, as can be the case when public safety is involved, but even then things are dealt with on a case-by-case basis.

Part of the approval process for the new lift is having guidelines in place to ensure no environmental loss resulted from construction and installation. The resort must do a thorough environmental screening report that addresses the impact of construction on all aspects of the local area – wildlife, plants, waterways, landscape, tourism, etc, and then pays what is called a performance bond, which is returned once construction is complete and all reclamation work has been performed to the satisfaction of Parks Canada. Environmental procedures are many and varied, and can include things like identifying rare plant species, training all construction workers on best practices with regards to bears and other wildlife, and removing and properly disposing of all waste material and old lift components.

So – now that the project is approved, construction can begin. What gets built first? Nothing – the first two months were almost exclusively devoted to removing the old lift. The main exceptions to this were the installation of sediment and drainage controls, and the installation of tower foudations, which were able to proceed before the removal of the old ones due to the slight re-alignment of the lift line.

July 24 2008 - Haul cable has been removed.

Aug 16 2008 - New tower foundations are excavated.

Once all excavations were complete and all forms in place, then came what is always a big day in the life of a lift construction project – concrete flying! A Bell 214 helicopter was brought in for the day, and even this big machine could only transport about 1 to 1.5 cubic metres of concrete per trip, and the foundation for the lift top station required almost 50 flights to complete. With the flying finished, the concrete was left to cure for a few days, then the pace of construction visibly intensified with the installation of the lift towers and the top and bottom stations.

Sept 15 2008 - Top station ready to receive concrete.

Sept 15 2008 - One load of concrete at a time...

Sept 15 2008 - ...and then another...

Just last week, the chair grips arrived from France, and chair installation wrapped up a few days ago. Currently the lift is going through a thorough inspection by provincial authorities to ensure all systems are functioning. One component of this examination is the load test, which involves placing barrels filled with water on each chair to simulate the weight of a loaded lift, and then running the lift under that load. Once this load test is complete, the chair is pretty much ready to go.

Dec 2 2008 - Almost ready to go!

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