The wind giveth and the wind taketh away …
Wind-transported snow can be a magical dream or a nightmare.
Story and photos by Matt Krane
*For more info on avalanches, snow science and avalanche safety, attend one of the upcoming public Breckenridge Ski Patrol info sessions, the third Thursday of each month (Feb. 16, March 15, and April 19) at the Ten Mile Room in The Village at Breckenridge.
SUMMIT COUNTY — One of the most superb skiing experiences at Breckenridge has always been the velvety flat, steep ‘windblown’ surface that often develops during post-storm wind cycles. It’s developing right now in Horseshoe Bowl, but to put things in perspective, less than a week ago the T-bar was not yet open to the public.
A fracture line is visible on classic convex avalanche from lower Peak 7 terrain, groomed snow in foreground.
So why now, after only a few days, is almost every line in the Bowl doable? Think back to the middle of last week when the high pressure shield finally gave way to a more zonal flow, bringing stronger impulses of snow: 4 inches, 7 inches, clearing, then 4-6 inches, clearing, then 10 inches.
Add the wind factor: We had winds averaging (hourly) up to the 50 mph range for several days. Notice a bit of a transformation in the look of the Ten Mile Range the past few days? Monday especially?
Peak 7 Avalanche, shot with the Avalauncher near the top of the Indy chair...from the parking lot. close to 1,000 ft. across averaging 4-6' deep, max. depth far lower right, 8 ft. it ran close to 1,100 vertical ft. i watched it run from the locker room.
Statistics compiled by the Breckenridge Ski Patrol’s weather and snow safety departments show that, for every inch of new snow measured at the official measuring station, up to 10 times amount that can collect on the upper mountain terrain, including, but not limited to, avalanche starting zones.
You will often hear that Breckenridge is one of the windier ski areas around. You will also hear that the wind is a GREAT friend to Breckenridge, often sending some of Copper Mountain’s snow over the Ten Mile Range to us. Think of all the mornings you’ve gotten up, gone to you favorite coffee stop, looked up and seen a cold, steely blue sky above Peak 8, when the clouds of wind-driven, ‘transported’ snow are so thick, they’re hard to distinguish from the real thing. If you’re like me, and you see trees bending on your street and hear the familiar voice of the wind ripping through, you get all excited. Okay, I do.
From the upper T-bar terrain looking north at Magic Carpet ridge on Peak 7. Note the four sets of fresh tracks off the Peak 6 ridge in the background, upper right, center.
At every morning meeting in the Peak 8 Patrol hut, after the mountain management projects are discussed, the ‘Master Blaster’ (avalanche technician) for the day has the floor. He or she has their way with weather data, previous avalanche activity, and forecasts … and spins out the morning’s control work. If the room wasn’t altogether quiet before, it is now. Weather data sheets are posted in the locker rooms, and we are all expected to at least familiarize ourselves with wind, snowfall, and temperatures.
What’s happened with the recent transformation of our snowpack, or at least snow depth, has kept the ski patrol in overdrive. We’ve been opening up new terrain, like the T-bar and 6 chair, the Back Nine on Peak Nine, Southside of Peak Ten, but not before weeks of control routes, ski cutting, “typewritering” (making very close, parallel ski cuts for compression), stringing boundary rope, hoping to be on top of things when the snow finally comes.
A team of avalanche control personnel, going out to shoot some of the adjacent terrain that did not slide, just above them.
As we begin to count this acreage in our terrain stats, we start looking farther. With the huge wind assist over the last few days, we’ve been able to set our sights on terrain further up and out.
Monday morning, we ran an ‘early-morning’ Avalauncher route, firing the Peak 7 Launcher — which is a few hundred yards southeast of the Independence chair’s top terminal. Any and all mountain activity in this area ceases (grooming, snowmobile traffic), so the team can fire at it’s targets, ranging from the End Zones on Peak 7 all the way to ‘Shadow Bowl’ just under the top of Peak 8′s north side.
In this broad view of the upper mountain terrain at Breckenridge, note the two avalauncher craters at far upper right— shot first — with no results. The fourth or fifth shot triggered the big slide on the main face.
The deepest part of the fracture scoured the existing snowpack down to rock. Again, the two shots at right did not yield results.
For the first slide of the season, this one ran really far, reaching the top of the compression knoll.
If anyone was out Monday, the extensive fracture line on the Peak 7 ridge, from Magic Carpet and CJs almost to Art’s Bowl, was very hard to miss: 700 to 800 feet across, maximum depths of six to eight feet, running 1,000 vertical feet.
It’s no surprise that our shallow, high altitude snowpack so far this year has been susceptible to ‘rotting out’, turning to highly unstable ‘faceted’ grains at ground level. One thing certain in the not-so 100 percent certain world of avalanche forecasting is that a big load on top of faceted grains is going to be problematic.
What’s happened in the last week? First avalanche fatality of the year outside Snowmass. Look this up on the CAIC accident site in their ‘accidents’ section-Burnt Mountain. The ‘slope’ that slid, buried, and killed the third skier in a party of three was 30-feet high. No typo: 30-feet high.
Snowmobile fatality north of Steamboat (do you think the weight of a rider and his machine is a bigger trigger than, say, a 200 lb. skier?). Inbounds, closed terrain fatality at Vail on Sunday, and another at Winter Park today …
So the high-pressure system yielded to a strong, zonal flow with wind and snow over the last week …all mountains … all on top of weak, faceted grains. I was in the Breckenridge Ski Area administrative parking lot this morning a few minutes after 8 a.m. when my radio crackled: “Peak 7! Look at Peak 7!”
The avalanche was magnificent to watch from this distance, very slow-motion. seemed like ten seconds before the powder cloud billowed up above treeline. To the folks on the gun tower, I’m sure it looked a little different.
The massive debris field viewed from the toe of the avalanche.
And this is how we build our base in the avalanche terrain at Breckenridge. Avalanche debris stops running at some points, anchoring itself. Succeeding slides anchor higher … and, don’t forget, the wind. Get up on the T-bar if the visibility is holding. The ‘North Bowls’ are starting to fill in nicely. ‘Forget-Me-Not offers the best view of this very recent avalanche.
In this tender snowpack and avalanche cycle, do NOT even think about ducking rope closures. It can be really bad for your health, and, as several individuals found out this weekend, and not so great for your skiing privileges. Remember, the Breckenridge Ski Patrol is available for questions, we’re a pretty accessible group of folk. The Patrol is continuing it’s well attended series of lectures on snow safety, snow physics, and common sense while traveling in avalanche terrain in February.
Another view of an massive avalanche debris field at Breckenridge. The ski tracks at left are the "exit" tracks left by ski patrollers after finishing nearby control routes.
Breckenridge ski patrollers check out the results of their avalanche control work on Peak 7.
Breckenridge ski patroller Andy Lapkass ventures out into the Vertigo slidepath on Peak 7 to assess cracking and settlement around his shot hole. Not for good skis!
Filed under: avalanches, climate and weather, Colorado, snow, Snow and weather, Summit County Colorado, Summit County snow and weather Tagged: | avalanche control, avalanches, Breckenridge Ski Area, Breckenridge ski patrol, Colorado, Matt Krane