In Like a Lion, Out Like a Lion

With March 2012’s position as the best March for snowfall ever at Lake Louise cemented in the books well over a week ago, things never really let up, and skiers yesterday (Friday) enjoyed what many are now calling the best day in years. There wasn’t a dry jacket in the house after a day of wiping snow from goggles and faces, and we’re still a little in awe at how fast it all happened.

For me, it was another morning of doing the daily snow report before leaving my home in Banff for the commute to the Lake, and another near heart-attack as I arrived at work to find conditions nothing like what I had reported. An earlier post described similar shock  a few weeks ago as our weather instruments had measured 21cm of overnight snow at our Pika weather plot, and I arrived at work to find maybe 1cm in the parking lot. That time it was temperature that resulted in such a discrepancy between base area and upper mountain snowfall amounts, and I need not have worried Рwe did indeed have lots of snow higher up.

This time it was the reverse – I reported 4cm of overnight snow at around 5:00am, and as I was speaking with Avalanche Forecaster Craig Sheppard as we got off the bus in Lake Louise at around 7:30am, he informed me that I had been way off, as our Pika plot was reporting close to 20cm. WHAT?!?¬† I couldn’t believe it – how did I make that mistake? Did I forget to carry the 1? I sat down at my computer shaking my head, wondering what had happened. Logging on to our weather plot site, I saw once again that I shouldn’t have worried, as almost all of that snow had fallen in the short few hours between when I did the report and when I arrived at work. 4cm was indeed correct at 5:00am, and we all ended up hardly believing what we were seeing.

To get 20cm or more in three hours means we were experiencing a snowfall rate of over 6cm per hour, which is about as hard as I’ve ever seen it snow here. Heck, we’re thrilled when it hits 2cm per hour! It didn’t let up, and as we made our way onto the mountain for a little avalanche control work, the grins just got wider and wider as it sunk in exactly how epic this day was going to be.

The snow was accompanied by wind, but the extent to which it affected loading and slope stability had yet to be determined. Our control team headed over to Flight Chutes via Home Run, and our first few ski cuts there made it clear that wind loading wasn’t an issue, so we quickly made our way back to the Summit Platter. There were three of us, so we split up to cover more ground. Two of us took care of the Headwall area, and the other went to the Wave at the bottom of Sunset/Skyline. Same story here – drifts as deep as 40cm, and little reaction to ski cuts. The avalanche forecaster than gave the word for the upper mountain lifts to open to the public for front side access.

Whitehorn 1 was next on the hit list, and we made our way down the skier’s right fenceline to control any cornice that had built up overnight. In these cases one patroller will travel along the very top of the cornice. taking care of any overhanging sections, while the other(s) travel in the same direction a few metres below, aiming to trigger avalanches in what are usually the deepest deposits of wind-blown snow (in what we call the “immediate lee”). In a few places some soft slab conditions had developed, and small pockets slid short distances, but otherwise there were no notable results. hat’s one of the beautiful things about good stability – teams can travel much faster through the terrain and get it open to the starving masses that much sooner.

Other areas of the mountain, such as Boomerang, stayed closed longer due to the fact that they are much bigger pieces of terrain that require a corresponding amount of control work. With the heavy snowfall, it’s harder to stay on top of control work in larger areas, and often teams will leave these alone and concentrate on smaller pieces and return to the larger ones once the snow lets up or all other control work is done. Despite the fact that teams generally weren’t seeing significant results in most areas, we still must visit all locations to ensure nothing gets missed.

And now for some numbers. Once the heavy snow let up around mid-day, we were counting well over 30cm at our Pika plot, and close to 40cm on the upper mountain. With this recent storm, we’ve now cracked 2m for the month, a feat not seen in any month since the season of 1955-56 – almost sixty years! When this March beat all others a few weeks ago, this season’s total snowfall to date had us tied in 5th place for all time season totals, with over a month still to go. With this past week’s snowfall approaching 50cm, we’re now solidly in 3rd place. Another 35cm or so will put us in 2nd, and another 70cm or so will put this season at the top of the list.

While it would be nice to have been here for a record-breaking season, either way we’re thrilled with what we’ve got this year, and there’s little doubt that we’re going to have solid skiing right up to closing day on May 6.


Kicking the Ant Hill


Buried!

Well, we keep trying to come up for air here in Lake Louise, but it just keeps snowing and we’re just going to keep on holding our breath! All departments had their hands full on Sunday, and none more than the avalanche control teams, who were faced with lots of snow and lots of terrain to cover, with little visibility to allow them to see where they were going or the results of their control work.

Base area at 8:00am Monday, March 5.

Saturday night saw 21cm of snow fall at our Pika weather plot, and other than a few hours Sunday morning, it never let up. The avalanche control teams made their way onto the mountain, altering their plan of attack slightly since Top of the World (TOW) chair was not running. Once on the upper mountain, crews focused on the front side of Summit and TOW, then made their way around to Whitehorn I, Rodney’s Ridge, and the terrain off of the backside of Paradise chair. These are usually the first backside areas to receive control work, since once they’re done we can open Saddleback and give an option to those looking for a green run in the alpine.

With the main pieces of avalanche terrain opened, crews headed toward Whitehorn II. What they saw when they got there were accumulations in wind-loaded terrain of 35-40cm. This snow had been accompanied by winds that blew steadily in the moderate range (20-50km/h) and had gusts in the high range (50+km/h), so there was the expectation that slab conditions had developed and that avalanches would likely be easily triggered by ski cuts and explosives. With the snow still coming down and the wind still blowing, visibility was poor, and crews had to move slowly through the terrain to ensure their own safety.

One of the issues in Whitehorn II is that there are numerous micro-features. In other words, one must consider not only the main part of the slope when conducting control work, but also all the little areas that have their own loading characteristics due to terrain features (rock outcrops) and changes in aspect. This makes for nit-picky work, especially considering that wind-loading was ongoing, and tracks made on these slopes were quickly being filled back in. With all of these conditions making it difficult to make progress in controlling slopes, the decision was made to keep Whitehorn II, Boomerang, Brownshirt, and North Cornice closed for the day.

Which brings us to today, and another 17cm of new snow added by 6:00am this morning. A significant difference last night was that there was much less wind, so the result was lighter, non-wind-affected snow laying over top of slabbier, slightly heavier snow. We call lighter snow over heavier snow building “right side up”, which is what we want. The opposite is “upside-down”, where you have heavier snow laying over lighter, and avalanches are more likely in these cases. However, with all that terrain closed on Sunday, we did not get the skier compaction that we rely on so heavily for slope stability, so avalanche control teams this morning were faced with up to 55cm of new, uncompacted snow in many alpine leeward slopes. Visibility is no better, so teams are moving very carefully through the terrain trying to get it open. Whether those runs that remained closed yesterday open today remains to be seen. There’s a good chance that if this snow keeps up and we get what some forecasts are calling for another 20+cm, then any progress will be hard-fought and short-lived.

Either way, the next few days look like they’re going to provide no shortage of epic turns, and, by hook or by crook, the terrain will open eventually!


Snow Reports Revisited

With Lake Louise getting walloped by over 25cm of snow last night, the daily snow reports (fax, e-mail, Facebook, etc) had a lot of great news and likely made many skiers and riders happy when they checked their computers earlier this morning. I wrote an article earlier this year about how the Lake Louise Ski Area conducts its snow reports, and there’s lots involved in gathering the information and communicating it to our customers via a variety of media.

I do the reports on Fridays, Saturdays, and Sundays, so when I awoke at 4:30am this morning I was greeted with the happy task of letting people know what an epic day we were about to be faced with. I’m able to access the precipitation gauge at our Pika weather plot via the internet from my home, which is handy since the weather in Banff, and snowfall in particular, is rarely indicative of what’s happening in Lake Louise.

A precipitation gauge does not measure snow – rather, it collects falling snow and melts it, then measures the amount of resulting water. We can then use a formula to convert water into snow equivalency, and it is this number that represents the number you see on our snow reports for mid-mountain snowfall.

As I approached Lake Louise this morning however, it was clear that the valley bottom received nowhere near the amount of snow we were seeing higher on the mountain. As I walked from my car to the office, I got a little nervous as I walked through maybe – maybe – 2cm on the ground. Had I been duped by our weather station? Had I sent out reports of huge snowfall when in fact we had anything but? As it turns out, I need not have worried, as our precipitation gauge did indeed tell the real story.

Why such a big difference between the base area and our plot near Pika corner? Warm temperatures, that’s why. With the base area temps lurking within a few degrees of 0C all night, there was a distinct line higher on the mountain where the heavy snowfall suddenly started. One of our lift maintenance staff drove his snowmobile from the base of Larch chair, which also had only a few cm’s of snow, to Paradise base, and he described it like driving into a wall of snow.

If I ever had doubts about the accuracy and reliability of our weather instrumentation, I don’t now (and I apologize sincerely to the precip gauge for the lack of faith)! We have powder, and lots of it. Now I can watch our guests enjoy what is surely to be a day for the books, rather than watch them wonder what the heck we were thinking reporting as much snow as we did. Enjoy everybody!