Summit County, CO Colorado
SUMMIT COUNTY " November saved the best for last, weather-wise, delivering the first icy blast of winter on the last day of the month. The thermometer reached the sub-zero zone for the first time Wednesday night, plunging all the way to 17 below zero. The high for Nov. 30 was just 5 degrees, making it by far the coldest day of the month.
Snowfall for November was close to average both in Dillon and Breckenridge, the two official measuring sites for the National Weather Service. Near Dillon Reservoir, Denver Water officials tallied 15 inches for the month, just .2 inches below the long-term average based on records going back to 1909. The snow came in clumps, between Nov. 10 and Nov. 15, when 10 inches fell, and then again on the last two days of the month, with five inches of dry powder.
Melted down, the snow equaled .67 inches of water, a little more than 30 percent below the average of exactly one inch. November is the driest month of the year at the Dillon site.
Nineteen days during the month were completely dry, and some of those were warm and sunny. The mercury climbed all the way to 61 degrees on Nov. 9 for the monthly high " the only time the temperature cracked 60 degrees. But highs did climb into the 50-degree range seven times.
Average maximum and minimum temperatures for the month were also close to the mark. The average daily high was 41.7 degrees (historic average, 40.9 degrees), while the average low was 12.8 degrees (historic average, 9.7 degrees).
In Breckenridge, where weather records go back more than 100 years, observer Rick Bly measured 19.5 inches of snow during November down in town. Up at the ski area, DayWeather Inc. reported total snowfall of 23.5 inches at 11,059 feet. Bly's tally was just a couple of inches shy of the average 22.2 inches, but the dry powder only melted down to .91 inches of water, about 60 percent of the average moisture content.
Average snowfall for December is 22.5 inches, but the month can bring big dumps.
The all-time December record was set in 1983, with 86.9 inches. The driest-ever was 1911, with 2.7 inches, the second-driest more recently in 1991, with 3.5 inches.
Bly said that, even though about 60 inches of snow fell during September and October, the spell of warm, windy and dry days in November ate away at the snowpack, especially at lower elevations.
But the Snotel map maintained by the Natural Resources Conservation Service (NRCS) shows that the statewide snowpack is at 104 percent of average, as of Nov. 30.
The Colorado River Basin is at 124 percent of average, the highest in the state, said Mike Gillespie, NRCS snow survey supervisor.
"All in all, we're maintaining above-average snowpack trends. We're at 104 percent of where we were last year at this date," Gillespie said, adding that it's still early in the season, only 20 percent of the way toward maximum snowpack accumulation.
The San Juans are still lagging, with the snowpack to date only at about 80 percent of average. But Gillespie said the anticipated effects of El Nino could help the southern mountains catch up later in the season.
Locally, the autumn snowfall helped maintain streamflows in the Blue River Basin at a time when they usually drop off, said Division 5 water commissioner Scott Hummer, who tracks flows for the State Engineer's Office.
Flows are at or above historic averages, with 22 cubic feet per second flowing at the Highway 9 gauge on the Blue River, Hummer said, adding that snowmaking crews at local resorts have had adequate supplies to work with.
The five automated snow measuring stations around Summit County are at a combined 152 percent of average, with the highest reading at Fremont Pass, at 175 percent of average.
For a statewide snowpack map, link to: ftp://ftp-fc.sc.egov.usda.gov/CO/Snow/snow/watershed/daily/co_update_snow.pdf.
Bob Berwyn can be reached at (970) 331-5996, or at firstname.lastname@example.org.