– The Backcountry Ski Touring Blog
  • Avalanches
  • Gear Reviews
    • Ski Reviews
    • Boot Reviews
    • Binding Reviews
    • Snowboard Splitboard
    • Book Reviews
    • Avalanche Beacon Reviews
    • Airbag Backpacks
    • Backcountry Electronics
    • Misc Gear Reviews
  • Podcast
  • Tips & Tricks
    • Ski Touring Basics
    • Boot Fitting
    • Fitness & Health
    • Gear Mods
  • Trip Reports
    • Fourteeners
    • Huts – Cabins – Lodges
    • Denali McKinley
    • 8,000 Meter Skiing
  • Stories
    • History
    • Humor
    • Land Use Issues
    • Evergreen Ski Touring
    • Poetry
  • Resources
    • All Posts Listed
    • 100 Recent Comments
    • Backcountry Skiing & Ski Touring Webcams
    • Ski Weights Comparison
    • Archives of WildSnow.com
    • Authors Page
    • Ski Touring Bindings
      • Trab TR2 Index and FAQ
      • Salomon Guardian & Tracker
      • Naxo Backcountry Skiing Bindings – Info Index
      • Silvretta Pure Backcountry Skiing Bindings – Info Index
      • Marker F10-12 Duke Baron
      • G3 Onyx Ski Binding FAQ
      • G3 ION Ski Touring Binding
      • Fritschi Backcountry Skiing Bindings – Info Index
      • Fritschi Diamir Frame Bindings Mount DIY
      • Fritschi Diamir Bindings FAQ
      • Fritschi Tecton FAQ
      • Atomic Salomon Backland MTN
      • Dynafit Tri-Step Binding 2001-2003
      • Naxo randonnee alpine touring AT ski binding FAQ
      • Dynafit Skiing Bindings – Info Index
      • Dynafit Binding Frequently Asked Questions FAQ
      • Dynafit Beast 16 FAQ Review 1
      • Dynafit Beast 16 FAQ Page Two
    • History
      • Ski Touring Binding Museum
      • Trooper Traverse Intro & Index
      • Randonnee Ski Touring “AT” ski gear — What is Hip?
      • Chronology
    • Backcountry Skiing Core Glossary
    • Gear Review Policy & Disclosures

– The Backcountry Ski Touring Blog

Banner
  • Avalanches
  • Gear Reviews
    • Ski Reviews
    • Boot Reviews
    • Binding Reviews
    • Snowboard Splitboard
    • Book Reviews
    • Avalanche Beacon Reviews
    • Airbag Backpacks
    • Backcountry Electronics
    • Misc Gear Reviews
  • Podcast
  • Tips & Tricks
    • Ski Touring Basics
    • Boot Fitting
    • Fitness & Health
    • Gear Mods
  • Trip Reports
    • Fourteeners
    • Huts – Cabins – Lodges
    • Denali McKinley
    • 8,000 Meter Skiing
  • Stories
    • History
    • Humor
    • Land Use Issues
    • Evergreen Ski Touring
    • Poetry
  • Resources
    • All Posts Listed
    • 100 Recent Comments
    • Backcountry Skiing & Ski Touring Webcams
    • Ski Weights Comparison
    • Archives of WildSnow.com
    • Authors Page
    • Ski Touring Bindings
      • Trab TR2 Index and FAQ
      • Salomon Guardian & Tracker
      • Naxo Backcountry Skiing Bindings – Info Index
      • Silvretta Pure Backcountry Skiing Bindings – Info Index
      • Marker F10-12 Duke Baron
      • G3 Onyx Ski Binding FAQ
      • G3 ION Ski Touring Binding
      • Fritschi Backcountry Skiing Bindings – Info Index
      • Fritschi Diamir Frame Bindings Mount DIY
      • Fritschi Diamir Bindings FAQ
      • Fritschi Tecton FAQ
      • Atomic Salomon Backland MTN
      • Dynafit Tri-Step Binding 2001-2003
      • Naxo randonnee alpine touring AT ski binding FAQ
      • Dynafit Skiing Bindings – Info Index
      • Dynafit Binding Frequently Asked Questions FAQ
      • Dynafit Beast 16 FAQ Review 1
      • Dynafit Beast 16 FAQ Page Two
    • History
      • Ski Touring Binding Museum
      • Trooper Traverse Intro & Index
      • Randonnee Ski Touring “AT” ski gear — What is Hip?
      • Chronology
    • Backcountry Skiing Core Glossary
    • Gear Review Policy & Disclosures
   

2019 Historic Colorado Avalanche Cycle Recap

by Manasseh Franklin November 18, 2019
written by Manasseh Franklin November 18, 2019
The last-known D5 slide occurred on Garret's Peak near Snowmass on March 14.

The last-known D5 slide occurred on Garret’s Peak near Snowmass on March 14.

Persistent weak layer + wet snow = historically massive avalanches

Unless you were living under a rock last winter, you likely heard about the rampant avalanches that funneled across the Colorado Rockies during the first half of March. Perhaps you spotted YouTube footage of a slide swallowing I70, or two snowmobilers out-gunning a massive snowcloud overtaking Maroon Creek Road near Aspen. Maybe you tried to travel Colorado State Highway 550 and found it was closed…for 18 days straight. Or you checked the avalanche forecast in hopes of harvesting some of the deep snow and found that not only your local zone, but several others were flashing black as though signaling certain death.

The fact is, no one alive had ever witnessed an avalanche cycle that big or destructive in Colorado. And while the 2018-19 winter itself wasn’t necessarily record breaking in terms of snowfall, it was unprecedented in its destruction. Colorado Avalanche Information Center Deputy Director Brian Lazar relayed the details to a fully packed house in the Cripple Creek Carbondale store on a balmy evening a couple of weeks ago. Here’s a brief recap of his talk.

Note: I’ve made an effort to highlight some of the major events and circumstances, but this is not a comprehensive list of all that transpired. Check out the CAIC website for additional details.

The trouble began, as mid-winter snowpack trouble often does, in October. Enough snow fell in the high country to linger through a relatively dry November until regular winter storm cycles started in earnest in December. The early snow left in its wake the dreaded persistent weak layer.

Fast forward to late February: each storm until that point had delivered just enough but not too much snow to poke at that weak bottom layer. CAIC forecasts held steady at moderate to considerable in most places. Colorado had a deep and consistent snow pack with an average of three meters rested atop that week layer. According to Lazar, it would take considerable force to make it move.

Well, considerable force, or considerable precipitation. Shortly after that, we got the latter.

A note on avalanche ratings. For the purposes of Lazar’s talk, he only spoke on the D scale, and did not include R ratings. The avalanche details that follow are all ranked according to potential for destruction as follows: a D1 is relatively harmless, a D2-3 can knock over and bury a person, and a D3-4 can bury a car. D5 is the most destructive possible, with the power to gouge forests, reshape mountainsides and basically render unrecognizable anything in its path.

The first cycle began on February 28. Over the days that followed, snow kept falling and avalanches were drier and largely concentrated in areas of thinner snowpack around Loveland Pass. They were relatively small at D2-2.5, not hefty enough to move a car but enough to bury a person.

By March 3 things were getting rowdy. The snow was coming in wetter and CAIC issued major avalanche warnings in 6 of the 10 zones in Colorado. A car collided with avalanche debris on Red Mountain Pass. Slides began to funnel across 10 Mile Canyon, closing I70 (sidenote: it costs the state approximately $1 million per hour to close the interstate). A backcountry skier was killed in a slide off of Lizard Head Pass. The first D4s were reported on Gothic Mountain and Whetstone. At the height of the storm, the Gothic area had received 3.4 inches of SWE.

According to billy barr Gothic’s venerable citizen scientist who has been collecting data on snowfall in Gothic for decades,“This avalanche path has run this far maybe 2-3 other times in the past 47 years and it just reached the road well past the East River and hit a cabin in Gothic.” Coincidentally, the last time it had ran was the same day, March 3, 40 years ago.

Farther south, Red Mountain Pass became a verified firing range with D3 and 4 slides continually breaking loose. CDOT closed Highway 550 at 9 p.m. on March 3. Due to avalanche danger and debris, it didn’t open again for 18 days.

Thermal image view of an avalanche breaking at night. CAIC uses thermal imagery to track avalanche activity, particularly close to road ways. Image: CAIC

Thermal image view of an avalanche breaking at night. CAIC uses thermal imagery to track avalanche activity, particularly close to road ways. Image: CAIC

Just as things were heating up, Colorado did get a small break in the storm pattern. But it didn’t last long and by March 7, the Breckenridge area was pushing 100 inches out of the storm and four regional zones were flashing black for extreme danger. By March 8, Lazar was making calls to avalanche experts asking, “remember all those avalanches everyone said would unlikely run again? I want a list of all of them.”

A Power Point slide from Lazar's talk. Each day of the storm cycle resulted in similar magnitudes of destruction and road closures. The photo of the crown on the left gives good scale for just how big these avalanches were breaking.

A Power Point slide from Lazar’s talk. Each day of the storm cycle resulted in similar magnitudes of destruction and road closures. The photo of the crown on the left gives good scale for just how big these avalanches were breaking.

On March 9, perhaps the largest avalanche ever seen in the U.S. unleashed in Condundrum Valley near Aspen. Running a mile long and 3000 vertical feet, it cross the valley floor and traveled partway up the opposite side. A house in its path was spared with minimal damage thanks to a wedge-shaped retaining wall.

A new avalanche path formed on Greg Mace Peak near Aspen and it was thought a new one was carved on Peak 1 near Breckenridge (historical photos later revealed it to be a slide path in the late 1800s). By March 10, 4-6 feet of snow had fallen in many areas, which equates to 4-6 inches of SWE. Schofield Pass near Marble received upwards of 12 inches of SWE. The Marble zone had received the brunt of the storms, and a few days earlier, the CAIC had closed popular backcountry ski access quarry road “to protect people from themselves.”

The snow just kept falling. March 11-14 marked the days when according to Lazar, “the San Juans completely fell apart.” A State of Emergency was declared for the region as D4 slides rumbled across the mountains. In Lake City, an avalanche swallowed the sheriff’s home while he and his daughters were sleeping. One daughter was buried. Miraculously, they all survived.

At this point, Lazar was thinking “I would love to go one day without a landscape altering event.”

On March 14, the last known D5 ran off Garret’s Peak near Snowmass, pictured at the top of this article.

And then, as quickly as the mountains had turned into a violent shuddering earthquake zone, the snowpack stabilized, seeming to have purged itself of every ounce of volatile energy. Within a few days, forecasts returned to moderate danger. Tons of debris filled valleys and mountainsides — snow piles, entire forests that had been plowed over, tree trunks snapped like matchsticks.

Hiking through evidence of a relatively small slide in Marble this past summer.

Hiking through evidence of a relatively small slide in Marble this past summer.

In the end, 87 slides rated D4 or bigger were reported to the CAIC and over 1000 slides total. Lazar posits that number as a gross underestimate. This summer, CAIC crews employed satellite to investigate widespread forest damage and found 4782 sites that looked as though significant timber had been destroyed. They will continue to use information gathered before, during and after the event to gain a better understanding of avalanche behavior.

So what caused this? Basal weak layers, a strong snowpack and enormous amounts of precipitation. Climate change could also be causing wetter, bigger storms to hit the Rockies more frequently. The whole event illuminated what avalanche forecasters and researchers know about avalanches, but more of what they don’t.

“Cycles like this allow for enormous insight into avalanche dynamics, trends, runouts, impact pressure and force,” said Lazar. “Ultimately we’re still learning.”

Here’s to hoping this coming season brings just as healthy a dose of snow, without the catastrophic slides.

Editor’s note: As backcountry travelers and citizens of mountain communities, we are all impacted by avalanche events. Thanks to organizations such as the CAIC, Utah Avalanche Center, Northwest Avalanche Center, the Bridger-Teton Avalanche Center and more, we can not only travel more safely in the backcountry but also be protected when public roadways are at risk. This season, consider how you can support your local avalanche organizations. Many (including the CAIC by way of Friends of CAIC) hold fundraisers to help fund the research and outreach that keep us all safe in the mountains. For information on upcoming events, check out your local forecaster’s website and post links for events in the comments.

7 comments
0
FacebookTwitterPinterestEmail
previous post
A Grand Traverse Gone Awry
next post
Blake Gordon Comes Down From the Himal — TDP 69

7 comments

John November 18, 2019 - 1:23 pm

Thanks for the summary. As a Washington resident I watched the coverage of the March storms with amazement.

Slim November 18, 2019 - 3:37 pm

You wrote:
“ During this storm cycle which was particularly wet for Colorado, one inch of snow equated one inch of SWE.”.
Is that a typo?

Kevin Woolley November 18, 2019 - 9:24 pm

I would be curious to hear from other long time residents how the March 2018 avalanche cycle in Colorado compares with the El Nino years in the early and mid 80s. I’d be curious to know about the year that the Lakeview slide path on Buffalo Mountain in Summit County last ran big, that must have been a comparable year. The slide path on Peak 1 is very impressive.

afox November 19, 2019 - 10:13 pm

Great article!

Garrett November 20, 2019 - 5:42 pm

Although widely reported to be a “new avalanche path”, the swath above Frisco on Peak One is an existing path with a very long return period. A week or so after all the excitement, the Summit Daily News published an old photo from the Breckenridge Heritage Alliance showing what looks like a near-identical scar in that spot. The photo was taken from east of Frisco @current day Lake Dillon. https://www.summitdaily.com/news/historical-photo-shows-avalanche-path-in-same-area-as-recent-peak-1-slide/
Photo is believed to be from 1880’s-1900, who knows how long it had been there when photo was taken. An “infrequent flier” for sure!

Although it’s slid big several times since, the current trimline on Buffalo’s Lakeview path dates to February of 1986(?) This was the same cycle when the Professor path wrecked the lift at A-Basin. There are still many identifiable ancient paths out there that we are waiting to see run.

Manasseh November 20, 2019 - 5:44 pm

Thanks for the clarification, Garret. I’ll edit to include the historical context.

Kevin Woolley November 21, 2019 - 12:03 am

Thanks for that history on Lakeview slide path, I was watching that path last March wondering if it would go. I can remember massive slides in the Wasatch as a youth during some of those 80s El Nino years, possibly 82? Some of those paths on Timpanogos were unbelievably massive, 3 or 4,000 feet, with hundred foot high stacks of snow and debris lingering into in May even on South facing slopes at 7,500 feet. I haven’t seen anything comparable there since the 80s, haven’t lived there since 95, but visit frequently.

Comments are closed.

Recent Comments

  • Clanicius on Spring Touring Essentials for Day Trips, Overnights, and Ski Mountaineering
  • DavidH on Exploring the Gem of Washington Pass
  • Gary on Exploring the Gem of Washington Pass
  • Jim Pace on Exploring the Gem of Washington Pass
  • Lou Dawson 2 on Breaking Down the New BD Pieps Beacon Recall

Gear Reviews

  • Atomic Hawx Ultra XTD 115 W Touring Boot Review

    April 7, 2021
  • BCA Scepter Ski Pole Review — Updated and Improved

    April 6, 2021
  • Spring Touring Essentials for Day Trips, Overnights, and Ski Mountaineering

    March 29, 2021

Trip Reports

  • Team WildSnow Recaps 2021 Grand Traverse Ski Race

    April 5, 2021
  • The Gothic Mountain Tour: Not Just a Training Race

    March 3, 2021
  • Making Turns and Skintracks at Bluebird Backcountry

    February 24, 2021

Totally Deep Podcast

  • Totally Deep Podcast 86 — Ross Herr of Dynafit

    March 9, 2021
  • Totally Deep Podcast 85 — Serious Powder Talk with Doug & Randy

    February 25, 2021
  • Drinking Beer with the Bench Girls — Totally Deep Podcast 84

    February 12, 2021

Tips & Tricks

  • Spring Avalanche Drama (and How to Avoid It!)

    April 2, 2021
  • Spring Touring Essentials for Day Trips, Overnights, and Ski Mountaineering

    March 29, 2021
  • Pocket Vs. Harness — Where Should You Wear Your Beacon?

    March 18, 2021

Ski Touring Stories

  • Envisioning a Friendly, Busier Backcountry — Shaun Deutschlander Q&A

    January 18, 2021
  • Giving Myself the Gift of Backcountry

    January 15, 2021
  • Six Who Dared — Elk Mountains Traverse & Richard Compton Tribute

    January 7, 2021

Newsletter Sign-Up

  • Facebook
  • Twitter
  • Instagram
  • About Lou Dawson
  • Authors Page
  • About
  • Contact
  • Copyright & Legal
  • Website Security

@2020 - All Rights Reserved. Designed and Developed by WildSnow


Back To Top

Read alsox

Exploring the Gem of Washington Pass

April 15, 2021

Ski Crampons — When To, When...

April 13, 2021

Ski Touring News Roundup Spring 2021

April 9, 2021