Sunny Days at the Lake

The eternal spring just seems to go on and on at Lake Louise, as we’ve lost count of the number of weeks that skiers have been enjoying sunny skies and warm temperatures. At the same time, despite the slushy conditions that appear every day after a few hours of blazing sun, the back side is still skiing like winter, thanks to a combination of north-facing slopes and dribs and drabs of new snow. Whitehorn II in particular is in wonderful shape, and skiers are enjoying lap after lap of great turns.

We at the resort consider the sun to be a bit of a mixed blessing, as melting snow presents a few challenges that are difficult to overcome without the help of Mother Nature. When snowmaking shuts down in February, it does so without knowing what the weather will hold for the remainder of the season, and there’s nothing like long hot spells to undermine the hard work of all the snowmakers who spent months in the deepest, darkest part of winter doing their best to ensure the runs, particularly on the lower mountain, would have enough snow to last until closing day in May.

In anticipation of this, many runs have “secret stashes” of snow, where snowmaking whales are only partly flattened, and then rounded off to look like they’re just a natural part of the underlying terrain. As thin spots get thinner, these stashes are slowly scraped off and the snow redistributed to fill in where needed. While not obvious in the winter to the untrained eye, walking the runs in summer it becomes plain to see that the large, low mound you skied over all winter was just snow, and the ground underneath completely flat.

As for the groomers, their jobs become a little more involved, as more thought is needed when thinking about routine things like where to turn around on a run that’s being groomed, and how to approach a dirt patch that has recently sprung up. Dirt is a cat’s worst enemy, not only because of the challenge in covering it up, but because dirt can get caught in the cat’s tracks and then dropped of in otherwise clean snow. Dirt, pebbles, and rocks act as heat magnets, and once in the snow, accelerate the rate at which snow melts. Cat drivers must always be conscious of how much they’re disturbing the snow underneath them.

Up until a few years ago, cats would always start their shift by fuelling up in the paddock at one end of the Operations building, then driving down the ramp next to Whisky Patrol. As spring progresses, this ramp quickly disappeared, and the cats would daily be adding more dirt to places where it wasn’t welcome. Then we started making snow in the paddock itself and the road leading into to it from above, off of the lowest reaches of Juniper Jungle. The paddock gets built up to the point where there’s a platform of snow seven or eight feet tall that can park the entire fleet. Barring a weather catastrophe, this ensures that the cats are kept off the dirt until  well after closing.

Once the hill closes for the ski season, the cats still have a few weeks of work clearing the mountain roads of most of their snow so that they melt sooner, and lift maintenance crews can access the lifts and begin their summer maintenance regimes. The roads are plotted by GPS, and the cats will get as close to ground as they can without actually disturbing it. the main reason for leaving a thin layer of snow on top is that all of the roads are riddled with water bars that are essential to proper drainage of melt water. A careless pass in a cat may damage these water bars, and if water is allowed to run down a road, it could spell disaster and mean weeks of repair work to get the road back into shape. Often, this damage can remain hidden under the snow, and it’s not until it all melts that we see the damage that could have been going on unchecked for weeks. Every year, though, we get better, and like everything else, experience goes a long way in improving systems.

There’s also something else that could result from the warm weather, something that usually stays far from the minds of skiers and staff. Readers of the local Banff and Canmore papers have already seen photos of both black and grizzly bears who have woken early from their winter slumber and are out on the hunt for food. I can remember a few occasions at Lake Louise where a bear was spotted on an open run, but in all cases made only a brief appearance before discovering they didn’t have the runs to themselves. For obvious reasons, a bear on an open run could cause some concern, and we have to whip into action to close the run to prevent any bear/human encounters. While keeping our distance, as we always should, it’s also important to monitor the bears as they travel, and this can pose a problem if they’re moving quickly through the woods or uphill. As rare as bear sightings on the hill are during ski season, we still have to plan for them.

*****

As for the Lowdown, I’ll be taking a few weeks off, but will be back to post through the end of the season and right into summer. This’ll be the longest I’ve been off skis since last summer, and I’m looking forward to enjoying the last few weeks of the season when I get back. See you then…

Spring morning at the Lake - March 28, 2010.

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Snowing All Day at the Lake

The snow that was forecast to fall in Lake Louise last night came later than expected, but it still came, and it has been snowing steadily all day (as of 3:30pm). Skiing conditions are great, and have been improving with every flake that falls.

It didn’t take long this morning for some skiers to discover that thanks to the east winds that have been blowing, terrain features and snow fences have had their drifts form on their leeward, or west, sides. As the day progressed and the winds continued, some were happy to discover that they were getting fresh tracks in places they had already skied.

There’s more snow forecast to fall tonight, so this weekend is shaping up to be a great one.

Bottom of Outer Limits, near the base of the Summit Platter.


And a Great Day It Was!

There were many smiling faces to be seen at Lake Louise yesterday as skiers and riders enjoyed some of the best conditions of the last month or two. The snow was soft and the sun stayed out all day, resulting in a day of skiing that everyone dreams about.

On avalanche control yesterday morning, things moved along quickly. Good visibility allowed control teams to work and travel around the mountain quickly, and the lack of slab conditions in the new snow meant that avalanche propensity was low, avoiding the intensive control work that would be needed if there had been stronger winds and slabs had formed. While the strength of the wind overnight (15-20kph, with gusts up to around 30kph) meant that slabs wouldn’t likely be an issue, it did come from other than the usual direction. Most of the time, Lake Louise gets wind from the southwest, but this storm saw it come in from the north. So, rather than thinking about how slabs may have formed, control teams instead focused on the unusual loading. In other words, a north wind will scour slopes that are usually wind-loaded, and vice-versa. Even thought the winds weren’t that strong, extra caution was required in places like Lipalian Chutes, which are usually scoured but this time had the potential for wind-loading.

As it turns out, the effect of the north wind was visible, but it didn’t really contribute to any elevated avalanche hazard, as the snow was very low-density. When ski cutting some slopes, the new snow would side below us, but not very fast and not gathering much mass. While a slab avalanche propagates out to either side and can widen dramatically from the trigger point, loose snow avalanches don’t widen, keeping to a narrow track as the snow goes downhill, as it did yesterday.

Another advantage of loose, low-density snow (other than making for great skiing) is that it is now available for transport by the wind (called fetch). When the wind does come, skiers can expect a whole different place, and it might be worth watching the wind forecast as much as the snow forecast in the near future.

Walking up to the top of Paradise (which is way faster than skiing down and riding the lift).

Early morning walk up to the top of Paradise chair for control work.

Not a single track (yet).

Near the top of Paradise Bowl, the small cornice in the bottom centre of photo is evidence of the north wind.

Bomb goes off in Swede's.


Snow at the Lake!

Put those golf clubs and bicycles away – winter hasn’t given up yet! The dreams of countless skiers and riders in the Bow Valley have finally been answered, as heavy clouds blocked the sun and opened up to provide 15-20cm of light fluffy snow at Lake Louise in the last twenty-four hours. Around 6cm had fallen by the end of the ski day yesterday, with another 13cm or so falling overnight. With the clouds parting this morning, the sky is getting blue and promising a fantastic day with fresh snow and great visibility.

Even though little wind accompanied this new snow, avalanche control teams will still have their hands full as there are still areas on the mountain with surface hoar. This new snow has produced the load we’ve been waiting for, and combined with the hard bed surface in well-skied areas, we don’t expect it to take much encouragement to get the new snow to avalanche.

It’s 7:30 am, and I’m off to do some avalanche control. I’ll add some photos and describe what we saw on our control routes shortly…


Snowfall at Lake Louise

There’s no question – snowfall seems to be on the minds of most skiers and snowboarders these days, as in “When is it coming?”. A few of our local forecasts are calling for snow around the middle of next week, but those forecasts are still a few days outside our normal window of confidence for accuracy.

I was asked recently if it was true that Lake Louise tends to get most of its snow in March, and while a positive answer may give reason to hope to powder-starved skiers, that is actually not the case. At the same time, I’ve been here long enough to know that anything can happen, and I’ve seen more than one “miracle spring”, where the skies open up and we ski powder for the last month or two of the season.

As far as monthly totals go, November, December, and January are the three months where we usually see the most snowfall. Since record-keeping began in earnest around 1970, those three months have each seen the year’s most snow 9 or ten times, with March at about 6 times, and February and April bringing up the rear. Since 1970, the season with the most snowfall  was 1971-72, when over 540cm fell during the six months of operation. December, January, and February each saw over 1m of snow, with February taking the rare lead in totals for that year. In contrast, February of this year didn’t even come close, with under 20cm total snowfall for a month that averages 50-60cm.

Most people will probably agree that if it’s not going to snow, the next best thing is sunny skies, and there’s certainly been no shortage of those this winter. One could not be blamed for thinking it was April while we were still in the throes of February, as afternoons saw soft slushy snow appearing on south-facing slopes, and hats and goggles were replaced by sunglasses and tans.

Everyone knows that sun and warm temperatures affects the snow surface, but it does so in one way that is less obvious and has important implications with regards to snow stability. Prior to the current run of warm weather, most places in the mountains of British Columbia and Alberta experienced widespread surface hoar – those light feathery snow crystals that develop on the snow surface when the right conditions line up. If they remain on top (in other words, if it doesn’t snow), they’re not an issue. It’s when more snow comes and accumulates on top that stability deteriorates and the avalanche hazard shoots up. The hoar crystals have no strength, and become a weak layer in the snowpack once they become buried. As soon as they can no longer support the weight of the snow lying on top, the layer of hoar crystals collapses, and widespread avalanching occurs.

We didn’t see a significant elevation of avalanche hazard in the Lake Louise area because there was never enough snow on top to create that critical load. In B.C., however, additional snow resulted in conditions becoming so touchy that the Canadian Avalanche Centre has issued three special avalanche warnings in two weeks. The most recent warning, which contains a link to some pretty graphic photos, can be found here:

http://www.avalanche.ca/uploads/SPAW/SPAW%202010-03-04.pdf

Now that the sun is hitting some of Lake Louise’s slopes full force, the surface hoar on those solar aspects is melting and becoming a part of the melt/freeze layer that results from the cycle of warm days and cold nights. On north-facing slopes, however, there’s less sun, and the surface hoar still exists and will be an issue when sufficiently loaded with new snow. That lack of solar radiation on north-facing slopes also explains why it’s possible to find winter-like ski conditions well into spring.