A snowy December has helped Summit County ski areas rebound from a slow start to the season that forced Breckenridge Ski Resort and Keystone Resort to postpone their opening days by one week in mid-November. Forecasts now indicate that early January will be snowy as well, with a weather system moving in that is expected to bring consistent snowfall until as late as Jan. 10.
A cold weather system will begin moving into the High Rockies on Monday afternoon, followed by an even colder surge of arctic air on Tuesday and Wednesday, according to the National Weather Service, which predicts sub-zero nighttime temperatures throughout the coming week.
The snow is expected to start falling on Monday and continue all week. Joel Gratz, a meteorologist with the forecasting website opensnow.com, said that snow could potentially fall almost every day through Jan. 10, although in a report he cautioned that the forecast was still highly uncertain.
“Subtle changes in the wind direction, the location of the cold front, the position of the jet stream, and the location and speed of the upper-level energy will make a big difference in the forecast, and there is still no consistency in the forecasts of these features,” he wrote in a web post.
“I think there’s a lot of confidence that this is going to be a very heavy snow week, but predicting where and when the big snows are going to be is difficult. There aren’t going to be big wallops, but we do expect to get 3 to 6 inches every day until the end of the week. ”Brian LazarDeputy director of Colorado Avalanche Information Center
The highest snow accumulations are expected on Wednesday. Open Snow is predicting that 2 to 4 inches of snow will fall during the day at Breckenridge, Keystone and Arapahoe Basin Ski Area on Wednesday, with 3 to 5 expected at Copper Mountain Resort. Projections from the Colorado Avalanche Information Center (CAIC) also indicate that the heaviest snow will come in the middle of the week.
“I think there’s a lot of confidence that this is going to be a very heavy snow week, but predicting where and when the big snows are going to be is difficult,” said CAIC deputy director Brian Lazar. “There aren’t going to be big wallops, but we do expect to get 3 to 6 inches every day until the end of the week.”
The snow that persisted leading up to the holiday season was a blessing for local ski areas. During October and November, snowpack depths were hovering around 30 percent compared to last season, but the strong December showing has closed the gap. As of Jan. 1, Arapahoe Basin’s snowpack was 117 percent of last season’s, while Keystone’s stood at 113 percent. Copper Mountain and Breckenridge currently have 100 and 99 percent of the snowpack they had last year.
The coming week of snowfall could be what local ski areas need to open up their remaining terrain.
The county’s resorts currently have between 84 and 95 percent of their skiable acreage open. Breckenridge currently has the highest percentage open, and 34 of its 35 chair lifts are currently running.
In the backcountry, meanwhile, CAIC cautions that avalanche conditions are trending toward higher risk of deep persistent slab (DPS) slides, which are low probability but are extremely destructive when triggered.
“The early season snow in October and early November was exposed to very cold, dry temperatures, which changed it to very weak, sugary grains that don’t provide a strong base,” explained Lazar. “If the forecasting pays out as anticipated, it will be enough to increase the danger of avalanches, and we still have weak, persistent layers that will be loaded.”
CAIC currently classifies avalanche danger in the Summit County area as moderate, but Lazar said the coming snowfall will likely change that. Because DPS avalanches are so destructive, the center advises checking forecasts after new snowfall and staying away from slopes that are more likely to have large avalanches.
Over the 2012-2013 and 2013-2014 seasons, only 5 percent of recorded avalanches were DPS slides, but they accounted for 42 percent of all fatalities over that period.
“It’s certainly trending (toward deep persistent slides)” said Lazar. “Prior to the snow coming this week, the past two weeks lowered avalanche danger, making them harder to trigger. But that means the avalanches that do go are bigger.”