Snowpack news

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From the Natural Resources Conservation Service (Mike Gillespie):

The latest surveys of Colorado’s mountain snowpack indicate continued favorable conditions for next spring and summer’s water supplies. According to snow surveys conducted by the USDA-Natural Resources Conservation Service (NRCS), the statewide snowpack continues this year’s trend of above average conditions and is 115 percent of average as of March 1. Basinwide snowpack totals are above average across most of the state with the only basins reporting below average conditions confined to the river basins in southern Colorado, according to Allen Green, State Conservationist with the NRCS.

Probably the most significant aspect of February’s weather events was the overall improvement in areas of the state, which up until this month, had been fairing quite poorly. Snowpack totals in the Sangre de Cristo Mountains and throughout the Rio Grande River Basin improved significantly this month, yet snowpack totals remain below average throughout this region. For many measurement sites in this area these February storms were the first significant snowfalls of the year. The Rio Grande Basin snowpack totals have the lowest basinwide snowpack percentage in the state at 88 percent of average.

In those basins west of the Continental Divide, snowpack totals decreased for the second consecutive month in February. Across the San Juan, Animas, Dolores and San Miguel basins, these decreases were large enough to lower the percentages to below average for the first time this year. Elsewhere across the state, particularly across the northern basins, these declines were less severe leaving snowpack percentages at above average levels.

The latest surveys once again illustrate the strong disparity between this year and last year’s snowpack conditions. With this year’s snowpack totals well above those of last year in most basins, only southwestern Colorado continues to report less snowpack than last year at this time. Statewide totals remain well above those measured on March 1, 2010.

Now, with only about one-quarter of the winter snow accumulation season remaining, most of the state can bank on seeing average to above average spring and summer runoff. The outlook for water supplies remains good to excellent across the Yampa, Colorado, South Platte Gunnison and Arkansas headwaters. “About the only basins likely to see below average runoff this year are the Rio Grande, the southern tributaries of the Arkansas River, and the southwestern basins”, said Green. The one advantage in the San Juan, Animas, Dolores and San Miguel basins lies with their slightly above average reservoir storage which will help to supplement expected lower water supplies.

Click on the thumbnail graphic above and to the right for the NRCS table of snowpack and reservoir storage levels by basin.

More coverage from Bill Jackson writing for The Greeley Tribune. From the article:

Adding to concerns is the latest outlook for March-May by the National Oceanic and Atmospheric Administration Climate Prediction Center. That outlook calls for a more than 33 percent probability of above-normal temperatures and below-normal precipitation, which does not bode well for the state’s Eastern Plains. Some areas have received decent moisture, but dry conditions, particularly in the southeast part of the state, could result in wildfires this spring and summer, NOAA said…

But the latest statewide surveys by officials with U.S. Department of Agriculture’s Natural Resources Conservation Service, indicate continued favorable conditions for the spring and summer water supplies, said Allen Green, state conservationist with the NRCS in Denver. The state’s snowpack is 115 percent of the long-term average as of March 1 and is 131 percent of last year’s numbers on the same date. The four main basins in the northern mountains, however, range from 121 percent of average on the South Platte to 131 percent on the North Platte. Compared to last year, however, the four basins — which includes the Colorado and Yampa/White — are at 153-183 percent of 2010…

The northern snowpack means there probably will be more water coming off the snowpack than can be stored in Lake Granby. That lake is the primary storage facility of the Colorado-Big Thompson Project, which brings a supplemental water supply over the mountains to 30 cities and towns in northeastern Colorado along with irrigation water for about 693,000 acres of farmland. Brian Werner, spokesman for Northern Water, which manages the Colorado-Big Thompson, said two meetings already are scheduled with the U.S. Bureau of Reclamation next week to the determine the best options for Lake Granby. “The simple math is that there’s going to be too much water coming into the collection system on the Western Slope this spring than we can either store and/or bring over to the east side,” Werner said. Letting water out of Granby back into the Colorado River could begin within the next couple of weeks to make room for at least some of the expected runoff this spring.

From the Summit County Citizens Voice (Bob Berwyn):

The March 1 anowpack in the Colorado River Basin was at 128 percent of normal, near the level it’s been at all year, and local weather watcher Rick Bly reported above-normal precipitation total for February to add to that total. For the month, Bly tallied 26.3 inches of snow, 11 percent more than the historic average of 23.5 inches. Melted, that snow added up to 1.85 inches of water, about 8 percent above the average 1.71 inches for the month.

For the year-to-date, total snowfall at Bly’s Breckenridge weather station is 136.1 inches, well above the year-to-date average of 101.5 inches and surpassing last year’s total winter snowfall of about 126 inches — but far from any records. As recently as 1995-96, 220 inches of snow had piled up in Breckenridge by March 1. The snowpack water-equivalent for the year-to-date at Bly’s gauge is 11.15 inches, a whopping 41 percent above the historic average of 7.52 inches. And that’s with the snowiest month yet to come, Bly said, adding that March has historically been reliable for steady snowfall, even in many otherwise dry years. The average snowfall for March is 25.52 inches and the biggest March on record was in 1899, with 120.4 inches — that was the winter that Breckenridge residents had to tunnel their way down Main Street. In the modern era, one of the biggest Front Range storms on record spilled over the Continental Divide to deliver 47.5 inches in March 2003. That was the storm that began on St. Patrick’s Day and dropped more than 80 inches on Evergreen, triggering avalanches near Georgetown and shutting down I-70 for several days.

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