{"id":20016,"date":"2019-11-09T10:57:23","date_gmt":"2019-11-09T17:57:23","guid":{"rendered":"https:\/\/www.skyhinews.com\/?p=61411"},"modified":"2019-11-09T10:57:23","modified_gmt":"2019-11-09T17:57:23","slug":"researchers-take-deep-dive-into-march-2019s-intense-avalanche-cycle","status":"publish","type":"post","link":"https:\/\/alwaysmountaintime.com\/krky\/local-news\/researchers-take-deep-dive-into-march-2019s-intense-avalanche-cycle\/","title":{"rendered":"Researchers take deep dive into March 2019\u2019s intense avalanche cycle"},"content":{"rendered":"
\n
This photo shows an avalanche path triggered by a skier on Loveland Pass. <\/strong>
Courtesy Colorado Avalanche Information Center<\/em><\/figcaption><\/div>\n<\/figure>\n

The avalanche cycle that struck the Colorado mountains in March destroyed a mining structure that had survived since 1881, produced three slides among the most destructive ever recorded in the state, obliterated the sheriff\u2019s house in Hinsdale County and blanketed roadways in places that had never been covered.<\/p>\n

Colorado Avalanche Information Center researchers are just starting to get a grip on the magnitude of events from March 1 to 14.<\/p>\n

\u201cNobody alive remembers anything like this happening,\u201d Brian Lazar, deputy director of the avalanche center, said Wednesday night at a presentation at Cripple Creek Backcountry in Carbondale.<\/p>\n

A standing-room-only crowd of about 100 crammed into the store to watch a slideshow featuring images that Lazar called \u201cavalanche porn.\u201d<\/p>\n

CAIC recorded nearly 1,000 avalanches between March 1 and 14. In reality, at least five times that many actually occurred, Lazar said. CAIC uses satellite imagery for avalanche research. The satellites focus on areas where timber was knocked down<\/a>. It indicated there were nearly 5,000 sites in the Colorado mountains last winter. Sometimes, CAIC is learning of massive slides from pictures provided of the carnage remaining this summer.<\/p>\n

It wasn\u2019t just the numbers but the sheer destructive force that made the March cycle so memorable.<\/p>\n

The D-scale is an assessment of the destructive potential of avalanches. A D1 slide is relatively harmless. D3 can knock down timber. D4 can destroy a structure and alter a section of forest. D5 is the highest, with the force to alter the landscape and even destroy a small village.<\/p>\n

CAIC has documented 87 avalanches at or above D4 during the two-week March cycle, Lazar said. To put that into perspective, there were 24 slides of that magnitude from 2010 to 2018 combined.<\/p>\n

Two of the three biggest slides in March occurred in Pitkin County. The first occurred in Conundrum Creek Valley<\/a> on March 9. The slide broke along 1 mile of the ridge south of Aspen Highlands, including the Five Fingers area. It dumped debris as deep as 200 feet in the creek.<\/p>\n

\u201cThis was the biggest avalanche I\u2019ve ever seen in the state of Colorado, probably the biggest avalanche I\u2019ve ever seen in the lower 48 states,\u201d Lazar said. \u201cIt wiped out thousands of trees.\u201d<\/p>\n

One house was spared only because a protective concrete wedge diverted snow, tree trunks and debris to avoid a direct hit. Lazar and other researchers used chainsaws to cut disks out of tree trunks left in the slide path to estimate of their age. That helps determine how long it has been since a slide of that magnitude struck the area.<\/p>\n

\u201cFrom some of the tree coring and some of the tree disking we\u2019re doing, this particular event may be more in the order of one in 300 years<\/a>,\u201d Lazar said.<\/p>\n

Another of the D5 slides occurred March 14 along a 2-mile ridge starting at Garrett Peak just outside of Snowmass Ski Area.<\/p>\n

\u201cYou\u2019ve often heard you can\u2019t get D5 avalanches in Colorado,\u201d Lazar said. \u201cI\u2019ve often said that myself because the terrain\u2019s just not big enough.\u201d<\/p>\n

He predicted that after more information is assessed, additional slides from the cycle will be reclassified as D5, most likely some in Gothic and Lake City.<\/p>\n

\u201cSo much went down in this (two-week) period, there\u2019s no way I can capture it in one talk,\u201d Lazar said at the start of his presentation.<\/p>\n

In a nutshell, here\u2019s what happened. Average to slightly above-average snowfall during the first half of the winter built a strong and stable snowpack throughout the Colorado mountains. March brought a series of exceptionally wet snowstorms.<\/p>\n

\u201cWe got hammered for two weeks straight,\u201d said Lazar, a resident of the Carbondale-area and a CAIC forecaster for the Aspen-Marble zone.<\/p>\n

The Aspen zone was among the hardest hit. While many mountains received 4 to 6 feet of snow, Schofield Pass near Marble received 12 feet. The storms added at least 4 to 6 inches of snow water equivalent \u2014 the amount of water in the snowpack.<\/p>\n

The snowpack couldn\u2019t handle that amount of loading with wet, heavy snow. In addition, a lot of snow was built up since there hadn\u2019t been a lot of slide activity earlier in the winter. As a result, the slides in March were huge.<\/p>\n

\u201cWhen things finally started failing, they went catastrophically,\u201d Lazar said.<\/p>\n

There are indications that wet storm periods might become more common.<\/p>\n

\u201cWith climate change and that kind of stuff happening, we\u2019re seeing 3- to 4-inch water storm events more frequently,\u201d Lazar said.<\/p>\n

CAIC\u2019s research of the historically large and intense cycle is heading in several directions. For example, some of the largest and most destructive timber was carried to the toe of the slide path. Conventional wisdom had been that it settles out earlier. The pattern displayed in March might force reassessment of damage potential.<\/p>\n

Also of interest is the somewhat random nature of slides. While many avalanche paths slid \u2014 some for the first time in decades and even more than 100 years \u2014 not all slopes did. Lazar showed a picture of a road sign saying \u201cEnd of Avalanche Area\u201d knocked over by an avalanche. That displays the uncertainty around big cycles, he said.<\/p>\n

Of greatest concern to CAIC is how to warn people in isolated mountain areas about avalanche danger. As population grows, fewer people have telephone landlines so they aren\u2019t accessible by reverse 911. The destruction of the Hinsdale County sheriff\u2019s house, which was occupied by three people at the time, demonstrates a need for greater communication with people in endangered areas, Lazar said.<\/p>\n

\u201cHaving gone down there, I can\u2019t believe anyone lived through this thing,\u201d he said.<\/p>\n

The March storm cycle was destructive enough. Avalanches that month killed two people \u2014 one in the backcountry and another in an accident while clearing a roof. Ten structures were hit statewide. Gas and power lines were damaged. Highway 550 over Red Mountain Pass south of Ouray was closed for 18 days. Slides even closed Interstate 70 and Highway 91 near Copper Mountain. Ten people were trapped in vehicles on open highways throughout the state.<\/p>\n

Once the snow stopped, avalanche conditions quickly returned to mostly stable for the remainder of winter and spring.<\/p>\n

\u201cWe went from pretty stable to the world falling apart to pretty stable just like that,\u201d said Lazar, who added that analysis of the intense two-week period will continue. \u201cThis is going to be years of research in the making.\u201d<\/p>\n

via:: Sky-Hi News<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

This photo shows an avalanche path triggered by a skier on Loveland Pass. Courtesy Colorado Avalanche Information Center The avalanche cycle that struck the Colorado mountains in March destroyed a mining structure that had survived since 1881, produced three slides among the most destructive ever recorded in the state, obliterated the sheriff\u2019s house in Hinsdale […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[56],"tags":[],"class_list":{"0":"post-20016","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-local-news"},"acf":[],"publishpress_future_action":{"enabled":false,"date":"2026-06-15 17:11:06","action":"change-status","newStatus":"draft","terms":[],"taxonomy":"category","extraData":[]},"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"distributor_meta":false,"distributor_terms":false,"distributor_media":false,"distributor_original_site_name":"KRKY Ski Country","distributor_original_site_url":"https:\/\/alwaysmountaintime.com\/krky","push-errors":false,"_links":{"self":[{"href":"https:\/\/alwaysmountaintime.com\/krky\/wp-json\/wp\/v2\/posts\/20016","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/alwaysmountaintime.com\/krky\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/alwaysmountaintime.com\/krky\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/alwaysmountaintime.com\/krky\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/alwaysmountaintime.com\/krky\/wp-json\/wp\/v2\/comments?post=20016"}],"version-history":[{"count":0,"href":"https:\/\/alwaysmountaintime.com\/krky\/wp-json\/wp\/v2\/posts\/20016\/revisions"}],"wp:attachment":[{"href":"https:\/\/alwaysmountaintime.com\/krky\/wp-json\/wp\/v2\/media?parent=20016"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/alwaysmountaintime.com\/krky\/wp-json\/wp\/v2\/categories?post=20016"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/alwaysmountaintime.com\/krky\/wp-json\/wp\/v2\/tags?post=20016"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}