Snowpack news: Dry January Decreases Snowpack Percentages

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Bump and update Here’s a release from the Natural Resources Conservation Service (Mike Gillespie):

January was a dry month across Colorado which has contributed to significant decreases in the mountain snowpack percents of average across the state. According to the latest snow surveys, conducted by the USDA – Natural Resources Conservation Service (NRCS), Colorado’s statewide snowpack decreased from 136 percent of average on January 1 to 117 percent of average on February 1. Decreases in snowpack percentages were measured in all of the major river basins of the state, according to Allen Green, State Conservationist with the NRCS. While this year’s snowpack is considerably better than last year at this time, the current statewide percentage ties that measured on this date back in 2009.

Those basins across southwestern Colorado experienced the driest conditions during January, recording only about one quarter of their normal precipitation for the month. Snowpack percentages decreased by 38 percentage points in the combined San Juan, Animas, Dolores and San Miguel basins; declining from 144 percent of average on January 1, to 106 percent of average on February 1. Similar decreases were also measured in the Gunnison Basin, decreasing from 158 percent of average a month ago, to only 125 percent of average.

While decreases in percents of average were measured across the state, the February 1 snowpack totals remain above average nearly statewide. Only the Rio Grande Basin has decreased to below average this month at 80 percent of average. “Without those big storms back in December, most of the state would be well below average right now. At this point, they’ve allowed us to endure a dry month, yet maintain good snowpack readings nearly everywhere,” said Green.

Even after experiencing a dry January, the current snowpack remains well ahead of that measured a year ago at this time. With the exception of southwestern Colorado, the 2011 readings are consistently well above those of last year. Statewide totals are currently tracking at 137 percent of those from a year ago.

The accumulation of the mountain winter snowpack is critical for Colorado’s water supplies. As much as 80 percent of the state’s annual surface water supplies originate from the melting winter snowpack.

Currently, the NRCS and National Weather Service River Forecast Centers are predicting that this year’s water supplies will be near, to slightly above average in most locations. Given the existing snowpack conditions, only portions of the Rio Grande and Arkansas basins are expecting summer runoff to be below average. With only about 40 percent of the winter snow accumulation season remaining, the next two months will be critical for maintaining the current streamflow forecasts for the state.

More coverage from Bruce Finley writing for The Denver Post. From the article:

“We’ve lost our cushion that we had back in early January from those December storms,” said Mike Gillespie, snow-survey supervisor for the Natural Resources Conservation Service. “We’re not in a panic situation. But it’s not encouraging to see such a sharp decline. “If we don’t get a good snowfall month in February or March and we go into a dry spring, we may be looking back at the December storms as the only good storms of the year. That would be pretty sad.”[…]

In the South Platte River basin that delivers much of the water that sustains the Denver metro area and other Front Range cities, snowpack decreased to 120 percent of average from 126 percent at the start of the year…

Federal analysts are preparing to issue a water-runoff forecast later this week.
They have determined that, from April through July, water shortages are likely in the Rio Grande basin and along some of the southern tributaries near Pueblo and Trinidad that flow toward the Arkansas River. Farmers in those areas can anticipate runoff 30 percent to 50 percent below average unless significant snow happens soon, Gillespie said. The runoff forecast for the South Platte basin still was shaping up as “slightly above average.”

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From Steamboat Today (Tom Ross):

The snow on Buffalo Pass is 10 feet deep…Veteran weather observer Art Judson keeps a pair of snow measurement stakes on Buffalo Pass to track the growing snowpack on a weekly basis. “The U.S. Forest Service took the readings on Jan. 25 and found 127 inches on the northern stake and 111 inches on the southern stake,” Judson reported. The 37 inches of water stored in the snowpack above 10,000 feet at Buffalo Pass on the Continental Divide north of Steamboat already is 128 percent of the average for Jan. 29. Steamboat Ski Area has recorded 252 inches of snowfall at midmountain this season, meaning 10 inches of snow in the coming week would push the ski area past the snow total of 261.75 inches for the 2009-10 season. The 20-year season snowfall average at Thunderhead is 335 inches, according to Steamboat Ski and Resort Corp. records. The record snowfall of 489 inches came in 2007-08…

The snow on the west summit of Rabbit Ears was 66 inches at midweek, but the water content, 23.1 inches, is more impressive than it is on Buffalo Pass in terms of its percent of average. The typical water content on Rabbit Ears at this point in winter is 15.2 inches, putting this week’s measurement at 152 percent of average. The Yampa and White river basins overall are at 128 percent of average.

More coverage from The Grand Junction Daily Sentinel (Dennis Webb):

The state’s snowpack fell from 136 percent of average on Jan. 1 to 117 percent at the start of this month, the U.S. Department of Agriculture’s Natural Resources Conservation Service said. Particularly dry conditions returned to southwest Colorado, which last month received only about a quarter of its normal January precipitation. That area also had started out the winter in poor shape until being hit by giant storms in later December. Drops in snowpack occurred across the state last month, but all basins remain above average with the exception of the Rio Grande, which is at 80 percent…

The Colorado River Basin is at 135 percent of average, down from 147 percent a month ago. Other readings as a percentage of average include the Gunnison and Yampa/White, 126 percent; South Platte, 120; North Platte, 132; Arkansas, 103, and San Miguel/Dolores/Animas/San Juan, 106.

More coverage from Sarah Castellanos writing for the Aurora Sentinel. From the article:

Judging by the snowpack levels taken on Jan. 27, which range from three to five feet, Aurora is on track to receive a quarter of its mountain runoff water supply from [Homestake] reservoir, [Mark Hanratty] said…

Greg Baker, spokesman for Aurora Water, says it’s still too early to know exactly how much water Aurora will collect from Homestake Reservoir. “We get most of our snow, our heavy, wet snow in March and early April — that’s what we actually count on,” he said. “What’s on the ground right now is great if it’s still there on the ground come March or April when we get these heavy snows. That’s bonus time … but this could all go away, or we could get a great reduction.”

On average, the city of Aurora uses between 46,000 and 50,000 acre-feet of water. The city collects a quarter of its water from the Colorado River Basin, a quarter from the Arkansas River Basin, and half from the South Platte River.

More coverage from The Aspen Times. From the article:

At Independence Pass, the snowpack is 125 percent of average, according to NRCS data. The agency also measures the snowpack at three sites each in the Crystal River drainage and the Fryingpan River drainage. Up the Fryingpan, the snowpack was 126 percent of average at Ivanhoe, 121 percent of average at Kiln and 142 percent at Nast Lake. Up the Crystal, the snowpack was 125 percent of average at Schofield Pass, 121 percent of average at McClure Pass and 139 percent of average at North Lost Trail near Marble. For the Roaring Fork basin as a whole, the snowpack is 127 percent of average. The Aspen Skiing Co. is reporting a 40-inch base at mid-mountain at Snowmass and a 62-inch base at the mountain top.

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