Tuesday, March 28, 2017

Welcome Ben Pritchett as the new ED and Lead forecaster for CBAC!

It comes with a heavy heart to announce I'm moving on from the Crested Butte Avalanche Center to take on a new role as the director of the Flathead Avalanche Center.  I'm looking forward to an opportunity for personal and professional growth in Montana. I'm grateful for the strong sense of community here that has made this place my home, both in town and in the backcountry.  Our mountain town is unique in how our backcountry users respect and look out for each other, and this energy is what has helped our little avalanche center thrive and grow to what it is.  Your observations, support, and donations help to make the CBAC one of the best forecast centers in the country.  Thank you for that, Gunnison Valley, and I hope that is something that won't change here as the backcountry evolves and becomes more crowded.

I'm excited to announce our new executive director and lead forecaster:  Ben Pritchett.  Ben brings a broad skill-set and diverse experience in the avalanche industry to the CBAC.  In the past 12 years, Ben has served as the program coordinator for AIARE and avalanche education coordinator for the CAIC, gaining valuable experience working with backcountry users, educators, and forecasters around the country.  Ben is a former forecaster for the CBAC and leads the forecasting program for the Grand Traverse.  He also owns and runs a backcountry guiding business here in Crested Butte.  Ben's industry connections and local understanding of our terrain, weather, and snowpack will contribute to the quality of our forecast products.

Ben at the 2017 Grand Traverse

Over the past 5 years, I have poured my heart into making this center the best it could be.  One of the hardest parts about leaving the CBAC was my sense of investment here and the fear of leaving the center high and dry on my way out.  The folks at the Flathead Avalanche Center were patiently willing to negotiate for a delayed start date which helped us conduct a thorough interview and hand-off process, and I'm glad we landed Ben.  Evan and Ian are two of the most dedicated and passionate forecasters I've had the pleasure of working with, and they are both planning on returning next year.  We brought on a new development director this past fall, Karen Williams, who has been working with us to improve our fundraising and outreach.  And with Ben joining the team,  I know now that the CBAC is in good hands moving towards a promising future with the goal of educating our community and saving lives from avalanche hazards. 


Zach Guy 

Tuesday, February 7, 2017

A letter of protest to surface hoar

Dear Surface Hoar,

First you bedazzled us with your shimmering feathers, glistening under the cloud layers that brought our unusual surface hoar event back in mid-January.  You are fragile and don’t belong in Colorado’s windy and sunny environment.   We thought to ourselves, “You’re a long shot, surely you won’t survive.”  But somehow you did.  Things started to go downhill on January 19th, when you got buried beneath a storm that came without wind, against the odds.
Unusual cloud layers and unusually widespread surface hoar layer in mid January.  Photo courtesy of MSF Films

Then more snow came, and it formed a soft slab above you, and your behavior started getting erratic through the last week of January.  We saw lots of natural avalanches, we saw avalanches breaking in dense aspen groves and on low angle slopes, and we saw slides remotely triggered from flat terrain. 
Video demonstrating the touchy and unusual avalanche behavior in late January.

It has been 2 weeks since the last storm, and we have heard about slides triggered on you almost every single day, either in our zone or our neighboring Aspen zone. There were a number of close calls and partial burials on the Aspen side. 
A slide on Mt. Emmons that caught a skier off guard.
 Things have started to quiet down this past week, and travelers are starting to let their guard down.  But with more snow on the way this week, we can’t trust you and your unruly and dangerous behavior.  It will become more sporadic and less predictable.

Video explaining our current snowpack structure on northerly/easterly aspects

I can’t recall the last time we had someone like you as widespread and troublesome in our snowpack.  Granted, a lot of things have changed in the past few weeks for the better, and we are thankful for that.  A lot of slopes have flushed.  Winds have blasted you and their overlying slabs away in places.  The sun has capped the snowpack with a stout crust on other slopes.  So now you are lurking on fewer slopes, but now the slabs above you will be growing thicker and more dangerous, and you will become more volatile again as more snow and wind prod at you.  We will see skiers and snowmobilers recreate on a lot of slopes with no apparent sign of problems from you, and our focus will be on freshly formed but manageable storm instabilities. But then somewhere you will react harshly as you buckle under increasing pressure, or someone pokes your small feathers on the wrong slope, and it will be bad news for everyone involved.  We know where you are most likely to be bothered, and that happens to be our favorite riding areas, northerly and easterly aspects near and below treeline. But we can't know for sure where or when you will strike next.  That scares us. 
Most of the persistent slab avalanche activity in late January was on surface hoar.
Read this observation for some caveats to this diagram. 
 At the CBAC, we ask that you resign from causing problems in our snowpack, and move back to Canada, where you belong. 


Zach Guy
Director of CBAC

Tuesday, January 10, 2017

The New Year storm....already historic and still counting!

The New Year storm....already historic and still counting!

By Zach Guy.  CBAC Director/Lead Forecaster

Credit: Xavier Fane

Since January 1st, the Gunnison Valley has been in the bullseye for heavy moisture streaming in from the Pacific.  CBMR recorded 47" last week and 30" this week as of Tuesday morning.  Irwin has recorded 87" out of this storm.  We usually hear from billy barr by 7 a.m. for Gothic reports, but we're getting radio silence this morning, so I'm assuming that he's given up on digging and has turned to his stack of movies and chocolate barrs.  But Gothic was at 86" yesterday.  Holy Cow!

Credit: Chris Miller
The first half of the storm came in pleasantly low density. On January 3rd, CBMR got 14" of 2% density snow. On the 4th, I came into the office to no snow, and by the time I left a few hours later, 10" had piled up, the kind that you clean your windshield with by blowing on it. On January 5th, Irwin got 20" of 5% snow, with steady 2"-3"/hour rates.   

The next major pulse on January 9th was just the opposite: warm and wet.  In a fantastic display of atmospheric absurdity, CBMR got 30" of dense snow.  Schofield picked 3" of Snow Water Equivalent (SWE) in a mere 16 hours. (SWE is the water weight of the snow...multiply by about 12 or 15 to calculate how much snow fell for average conditions).  It felt like I had just gotten out of the shower when I got back from the field to investigate a 3 foot slide that ran naturally across Kebler Pass Road.  Trail breaking was miserable, wallowing through thigh deep, upside-down heavy snow. I'm sure countless people pulled out their backs shoveling. The Crested Butte Community School closed for the first time since 1970.  CBMR closed early due to safety concerns.  I counted at least two emails from billy barr that started with "It's a mess". With the rain line hovering near town, roof avalanches were ripping out right and left.  Winds have been howling.

Of course, we haven't had much in the way of visibility since then, and with few people traveling in the backcountry right now, observations have been limited.  Two large slides ran across Kebler Pass Road, piling 8 feet of debris on the road.  I caught just enough clearing to spot a slide that ran to ground near Red Ridge. A lot of the paths near town were still holding as of yesterday afternoon.

Now to the weather stats. Schofield Pass SNOTEL has been operating since 1985.  As of Tuesday morning, the site has picked up 10.5" of SWE since New Year's. This storm has surpassed all but one major storm in the past 32 years.  We have another major pulse arriving Tuesday night into Wednesday and continued stormy weather into the weekend.  This could push us beyond the historical 1986 storm, which reached 13.5" of SWE.  Yowza!!

We have had avalanche warnings and high avalanche danger for 4 days of this storm.  Tomorrow we trended to extreme danger, something I've never done in my 6 years here (We missed a day of extreme danger back in 2014).  Extreme danger calls for a very unusual event: widespread natural avalanche activity D3 in size, with the potential for some natural avalanches D4 or greater in size. Avalanches will break trees and may include areas of mature timber. Avalanches will likely run full path through all elevation bands, thus we paint all elevations black. These types of events happen so rarely that they are incredibly tough for forecasters to predict.  In the 5 storms shown above, all of them saw widespread natural activity, and with the exception of 2010, all of them saw long running avalanches to the valley. 2010 saw most avalanches run before they reached the volume capable of historic paths. This year, we don't have as pronounced of weak layers as in some years, but we're seeing an exceptional load that could break the camel's back: the volume is already there.  We will see what data we have tomorrow and how the next pulse of snow and wind is shaping up. Either way, it is very dangerous in the backcountry right now.

Credit: Xavier Fane
Regardless of whether we are at high or extreme tomorrow or the following days, our travel advice is pretty simple during an avalanche warning. Just stay off of and out from under avalanche terrain: slopes steeper than about 30 degrees or low angle slopes connected to steeper terrain above.  Most backcountry travelers know better than to jump into big alpine faces during this kind of storm, but it can be the sneaky or small avalanche paths that kill you.  We are more worried about a shoveler getting buried in a roof avalanche, or a kid on the sledding hill, or a dog walker on Peanut Lake Road, or a commuter to Irwin during storms like this.   Our snowpack is shaping up to be a deep and strong one this year, so let's give it its due time to recover from this historical storm, and then let's enjoy a great winter ahead!  And be sure to thank your local ski patrollers for their tough and dangerous work to reduce the risk of avalanches at CBMR. There have been two patrollers caught and carried in large slides this week. Those guys and gals hang it out there to get terrain open for you.