Blue snowpack in Summit County well above normal
By Bob Berwyn
SUMMIT COUNTY — November snowfall added up across much of northern Colorado, with some local high-elevation Snotel sites registering a snowpack that’s nearly twice the average for the end of November. Specifically, Copper Mountain‘s reading is 189 percent of normal, with Grizzly Peak at 158 percent and Fremont Pass at 145 percent of normal.
The only sites that were a bit below average are at lower elevations, for example Summit Ranch, at about 72 percent of average, according to Blue River Basin water commissioner Scott Hummer. Across the Blue River Basin, the snowpack is at 136 percent of the long-term average for Nov. 30, Hummer said, emphasizing that it’s the April and May readings that are critical for summer water supplies.
The November snow totals only represent a small percentage of the seasonal totals, but at least the winter is off to a good start, Hummer said. Statewide, the Nov. 30 snowpack is close to normal, at 104 percent. the highest reading comes from the North Platte Basin, at 150 percent of normal, while the lowest reading is in the Rio Grande Basin, at only 56 percent of average.
So far, precipitation patterns have been in line with La Niña-based predictions that call for better than average snowfall across the northwestern part of the state, with below average snow down south.
“It’s uncanny how well the prognosticators have been able to pinpoint the La Niña and El Niño winters, just in the last five years or so,” Hummer said. All the state’s northern basins have above-average snowpack readings, with the Colorado Basin at 131 percent of average. The farther south you go, the lower the totals, with the Gunnison Basin at 87 percent, the Arkansas at 74 percent and the San Miguel, Dolores, Animas and San Juan Basin at 66 percent.
The South Platte — the key basin to Denver’s water supply, is at 116 percent of normal, thanks to snows in the headwaters area. Beyond that, the entire Front Range, and the plains out toward Kansas are now listed on the drought monitor under a D1 status, for moderate drought conditions — another forecast effect of a La Niña winter.
Regular autumn snowfall helped Summit County streamflows stay near average after they dipped very low in late summer, Hummer said. For example, the Blue River below Goose Pasture Tarn was flowing at 10 cfs Tuesday morning, just 1 cfs below the 27-year average. The record minimum flow was 7,8 cfs in 1993, the record high was 21 cfs, in 1985.
Some local stream gauges are frozen, but the Snake River, just below Keystone’s snowmaking diversion, was flowing at 16. 2 cfs Tuesday morning, close to average and well above a state-set minimum of 6 cfs.