An avalanche tore down a mountainside in Colorado’s Summit County and slumped across Interstate 70 on Sunday afternoon amid peak after-ski traffic, forcing state highway authorities to close one of the nation’s main east-west transportation routes. Colorado Department of Transportation snowplows and Summit County emergency crews raced to the scene between Frisco and Copper Mountain shortly after 5 p.m. Snowplows cleared I-70 within 90 minutes. “It hit the road. There were no cars buried. No injuries,” Colorado State Patrol Trooper Tim Schaefer told The Denver Post. “It was more than a dusting of snow. There was also tree debris on the road,” Schaefer said. Snow debris from Avalanche slide today on I-70 #SumCo pic.twitter.com/0dBmiFnEoU — SCSOPIO (@SummitSheriffCO) March 4, 2019 CDOT officials issued a bulletin saying westbound lanes of I-70 were closed at Frisco “for safety reasons” as crews rushed to the blocked area along eastbound lanes. State Patrol officials said eastbound I-70 was closed at Exit 196, near Copper Mountain. By 6:30 p.m., traffic was flowing again. Multiple agencies raced to the scene along I-70 at dusk, creating a snarl of flashing red, blue and yellow lights, surrounded by blocked vehicles. Heavy snow across the high mountains created conditions favorable for avalanches. While avalanches frequently block Berthoud Pass west of Denver and Red Mountain Pass between Ouray and Silverton in southwestern Colorado, avalanches typically do block traffic along I-70, one of the nation’s main east-west transportation routes. CDOT crews try to control avalanches in areas where roads cut through steep terrain. This avalanche was not set off deliberately as part of “avalanche control” work, Schaefer said. “With all this heavy snow, and everything falling this fast, CDOT does their best,” he said. “This is a big storm. There’s a lot of snow in the high country now. They did a good job of clearing that road.” Avalanche danger scale A live look at Colorado’s avalanche danger scale, provided by the Colorado Avalanche Information Center:<doc-sep>There are two sides to every snowflake. As skiers celebrate a winter chock-full of fluffy powder, Colorado forecasters and transportation workers have dealt with a wave of historic avalanches this week that flooded highways with feet of snow, making for ungodly commutes and dangerous conditions. Three major avalanches Thursday — at Vail Pass and near Copper Mountain — marked the third day of major snowslides this week, shutting down Interstate 70 for hours, trapping cars and rupturing a natural gas line. The threat of more slides forced the Arapahoe Basin ski area to close Thursday and delay Friday’s opening, while Copper and Breckenridge limited their operations. Avalanches also spilled rivers of snow and tree debris onto the interstate through Summit County on Sunday and Tuesday, closing both eastbound and westbound lanes of traffic for hours. “We are seeing avalanches run longer than they have in 50 years in some cases,” said Spencer Logan, a forecaster for the Colorado Avalanche Information Center. “We’ve gotten a lot of snow on the mountains and it is starting to come down.” RELATED: Snowstorm pushes Denver above average monthly snowfall total for first time in 25 months Thursday’s first avalanche brought 6 feet of snow down onto the highway overnight, mostly over the westbound lanes at Vail Pass. One truck was caught in the slide, though officials said the driver was not seriously injured. Nobody was hurt in the second avalanche, which occurred at about 5 a.m. near Copper and severed the gas line. The third avalanche came crashing down around 3:50 p.m., burying a stretch of Colorado 91 between Copper Mountain and Leadville, about a mile from the ski resort. Three vehicles were partly buried in that slide, though no people were reported injured. Historic avalanches Colorado has notched 2,000 avalanches so far this season, including 288 in the past week, said Ethan Greene, director of the CAIC. Most of these are not enormous, he said, but the total that are significant is very unusual, he said. “These are 1-in-30 to 1-in-50-year kinds of avalanches,” he said. The avalanche danger is not only serious, it’s historic. This is the first time in about 12 years that the CAIC has elevated multiple zones in the state to 5-out-of-5 “extreme” avalanche danger, Greene said. Extreme avalanche danger in the central Colorado mountains – via @NWSBoulder. Colorado Avalanche Information Center says "Do not travel in the backcountry. Historic avalanches expected to valley floors." For additional information visit https://t.co/2Nu3YzOs3r #cowx pic.twitter.com/moVf90as3l — JeffcoColorado (@JeffcoColorado) March 7, 2019 To put it in perspective, he said, over the past five or six years, “extreme designations account for only about 1 percent of the forecasts we put out.” Thursday, state officials elevated the danger to its highest levels for the Aspen, Gunnison, Sawatch, Vail and Summit county zones. “Travel in, near or below avalanche terrain is not recommended,” Friends of CAIC tweeted Thursday. “Keep it simple and just AVOID the backcountry.” Avalanche danger is high (level 4 of 5) for the Steamboat and Flat Tops, Front Range, Grand Mesa, North San Juan and South San Juan zones. Six people have died in avalanches this season, according to the CAIC. It’s the most in five seasons, but close to the long-term average, Greene said. The season, however, isn’t over yet. “We’re definitely concerned about the safety of people in the backcountry,” Greene said. “Given the conditions, and the amount of time left in the winter, there probably will be other accidents.” So will these avalanches continue? Forecasters say it’s difficult to project. “A lot of what we do is forecast over fairly short time frames,” Greene said. “Over weeks and months is really hard.” The weather could warm up quickly, he said, which could mean wet avalanches. Or we could go into a more gradual warm-up. “It could be almost anything at this point,” Greene said. Chris Bianchi, a meteorologist for Weather Nation and a Denver Post contributor, said more snow in the coming days certainly won’t help. He described avalanches as kind of like a snow version of Jenga. Storms are piling up 15 to 20 inches of snow at a time, followed by a three-day break — when ice can form — and then another 15 to 20 inches of snow falls on top of that. And repeat. Eventually, those layers loosen up. “That is a worst-case scenario,” Bianchi said. Classic El Niño conditions coming from the Pacific Ocean all winter have created nonstop waves of moisture, Bianchi said, leading to above-average snowfall in Colorado’s high country. Snarling traffic These major avalanches — starting Sunday near Copper Mountain — have snarled traffic and caused miles-long backups along I-70, one of the nation’s main east-west transportation routes. Tracy Trulove, a spokeswoman for the Colorado Department of Transportation, said her team has been working round-the-clock throughout the state. She had been up since 1 a.m. Thursday, dealing with the latest wave of avalanches. “This has been an extremely hectic week,” she said. While I-70 has garnered much of the attention, there have been other avalanches across the state that have required CDOT’s attention. “And we’re not a big team,” Trulove said. The highway is the main thoroughfare for skiers and boarders coming from metro Denver and the Western Slope. And that means many have been stranded in mountain towns such as Frisco and Silverthorne. “Sunday, it was horrible,” said Nathan Cornelius, an employee at the Wyndham Hotel in Frisco. Sunday happened to be Cornelius’s first day on the job. And it was rough. “People weren’t so much mad at us,” he said. “They were just mad in general.” Skiers who just spent hours and hours sitting on the highway had come to the hotel looking for a room. But there were no rooms — not there, not anywhere in town. “So people slept in the parking lot in their cars,” Cornelius said. “Including myself.” The next day, it took him 3.5 hours to drive from Frisco back to his home in Georgetown. With more road closures Thursday, the hotel saw a steady stream of bookings, he said, but nothing close to Sunday level. Not yet, anyway. “This time,” Cornelius said, “I was smart enough to reserve a room.” Avalanche danger scale A live look at Colorado’s avalanche danger scale, provided by the Colorado Avalanche Information Center:<doc-sep>A backcountry guide leading a group of skiers near Jones Pass died in one of the more than 30 avalanches reported in Colorado’s high country on Thursday. Powder Addiction employee Hans Berg, 48, was killed in an area where the avalanche risk was high Thursday and Friday and was under an avalanche warning until Saturday morning. “This is scary stuff. Avalanches are running bigger than many (of) us have seen in our careers,” the Colorado Avalanche Information Center posted on Instagram. The warning also applied to Vail and Summit County, Sawatch, Aspen, Gunnison, Grand Mesa and Steamboat and the Flat Tops. “This is not the time to try to outsmart Mother Nature,” the Colorado Avalanche Information Center posted. The warning advised people to avoid traveling in, near and below avalanche terrain. There have been an unprecedented 226 reported avalanches — natural and triggered by blasting to reduce the danger — in the past week, CAIC said. Thursday was the first time that four backcountry zones — Vail and Summit County, Sawatch, Aspen and Gunnison — were rated as extreme danger since the avalanche center began its 10-zone forecast 12 years ago. CAIC classified the slide that killed Berg as a 4 on scale of 5 for its size, width and destructive force. Slides of similar size and power were reported Thursday near Copper, Leadville, the West Elks and near Twin Lakes. One ruptured a gas line near Copper Mountain that shut down Interstate 70 between Frisco and Copper, and another buried the interstate over Vail Pass. Powder Addiction said in a Facebook post that the slide was triggered by two nonguided skiers on a dangerous slope above its guided group. “The Powder Addiction group was skiing in accordance with standard operation procedures in a well-known and frequently skied area,” the Facebook post says. “The Powder Addiction family is distraught by Hans’ passing. Our thoughts and prayers are with Hans’ family and friends during this heartbreaking time.” Berg’s death is the second avalanche fatality in Colorado this week and the seventh this year. Scott Spencer, 53, was killed in a slide Sunday near Telluride. CAIC downgraded the risk in the areas under the avalanche warning to high Friday morning. U.S. 6 over Loveland Pass remained closed, as did the nearby ski resort Arapahoe Basin. Upper elevation areas of Breckenridge, Keystone and other I-70 resorts were inaccessible much of Thursday as ski patrol blasted slopes to mitigate avalanche danger. An inbounds avalanche was confirmed at Breckenridge Ski Resort about 12:30 p.m. Friday on an expert-rated trail off the Imperial Express SuperChair, the Vail Daily reported. Spokeswoman Sara Lococo said no guests are believed to have been injured. U.S. 550 over Red Mountain Pass remained closed. No travel has been allowed on the treacherous, winding San Juan Mountains highway after massive avalanches dumped 30-plus feet of snow, trees and debris on the roadway. U.S. 50 over Monarch Pass and Colorado 91 on Fremont Pass reopened Friday. The National Weather Service in Boulder said heavy snow was moving into the central and northern mountains Friday afternoon. “Expect slow travel, with whiteout conditions possible at times, along the I-70 stretch from Glenwood Springs to Vail Pass to Georgetown,” the weather service said. Most of Saturday and Sunday are expected to be dry, though slow-moving, southerly storms could deliver more snow to Colorado beginning Monday and continuing into Friday. Despite the danger to mountain drivers and backcountry travelers, the almost nonstop snowfall since the start of March has boosted Colorado’s snowpack to 129 percent above average for the water year, according to data from the Natural Resources Conservation Service. Since March 1, the number of inches of water equal to the amount of snow that has fallen has skyrocketed from just above 14 inches to more than 17. That puts the 2019 water year as the fifth largest since 1987 and on track to reach or exceed its peak before the spring snowmelt. The southwest corner of the state has particularly benefited from recent precipitation. The region was at 138 percent of its median Friday and 231 percent of last year’s snowpack as of March 1. The Arkansas basin, which encompasses Pikes Peak and Colorado Springs, was at 136 percent of its median and 192 percent of last year’s average. No part of the state is considered to be in exceptional drought, and less than 1 percent is rated as in extreme drought, according to the U.S. Drought Monitor. Just over half of Colorado is in moderate or severe drought, and another 31 percent is abnormally dry.<doc-sep>
State officials catapulted their gauge of avalanche danger to the highest level after Colorado notched 2,000 avalanches so far this season, and a series of avalanches swept over Interstate 70 near Vail and ruptured a natural gas line in Copper Mountain on Thursday. Officials are describing the avalanche danger in the state as “historic.” “We are seeing avalanches run longer than they have in 50 years in some cases,” said Spencer Logan, an avalanche forecaster for the Colorado Avalanche Information Center. “We’ve gotten a lot of snow on the mountains and it is starting to come down.” The center upgraded its avalanche danger scale to “extreme” for Vail and Summit County, Sawatch, Gunnison and Aspen. Logan said that some of the avalanches have plunged thousands of vertical feet and are knocking out huge trees. In an average winter season, CAIC records around 3,000 avalanches. This year, there have already been 2,000 avalanches, even though the most active period for avalanches is in the spring when the snow melts, Logan said. “We’re shaping up for an interesting spring,” he said. A number of factors have triggered a surge of major avalanches the past week, Logan said. The recent snowstorm that began Wednesday night dropped 20 inches of dense snow in a matter of hours, said Tracy Truelove, spokeswoman for the Colorado Department of Transportation. A heavy new layer of the heavy dense snow on weaker layers of lighter snow creates prime avalanche conditions, Logan said. On top of that, high westerly winds can topple the recent shelf of snow into an avalanche. Forecasts also call for upcoming rain, which often increases the probability of slides, he said. Because of these factors, the CAIC increased its avalanche danger scale to extreme, he said. So far this season, six people have been killed in avalanches. “Do not travel in the backcountry. Historic avalanches expected to valley floors,” the CAIC says. The agency is warning people to avoid all avalanche terrain. At this level, the likelihood of avalanches caused naturally or by humans is “certain,” according to the North American Public Avalanche Danger Scale. Two giant avalanches near Vail and Copper Mountain on Thursday morning triggered the closure of Interstate 70 in both directions from Vail to Frisco. There is no estimated time the highway will be reopened. Colorado Department of Transportation crews closed both eastbound and westbound I-70 for more than nine hours Tuesday when officials triggered an avalanche on Mount Bethel that spilled 8 to 15 feet of snow across the roadway. The work was done to mitigate unexpected avalanches. On Sunday, an avalanche tore down a mountainside between Frisco and Copper Mountain, sending snow and tree debris across I-70. Skiers trying to return to the Denver were delayed for several hours Sunday night. EXTREME Avalanche Danger (5 of 5) and an Avalanche Warning for Vail and Summit County, Sawatch, Gunnison and Aspen zones. Do not travel in the backcountry. Historic avalanches expected to valley floors. #CAICSummit #CAICSawatch #CAICAspen #CAICGunnison pic.twitter.com/xQuOXw6wTf — CAIC:Statewide Info (@COAvalancheInfo) March 7, 2019 Avalanche danger scale A live look at Colorado’s avalanche danger scale, provided by the Colorado Avalanche Information Center: