#Snowpack/#Drought news: “It’s getting warmer and we’re seeing less precipitation in the wintertime” — Jeff Derry

Westwide SNOTEL basin-filled map April 12, 2018 via the NRCS.

From The Aspen Times (Brent Gardner-Smith):

The members of the Rio Grande Basin roundtable got a disheartening report this week about this year’s snowpack and likely runoff in the Rio Grande River basin, as well as an update on a 30-year warming and drying trend.

“We’re going to have low stream flows,” Craig Cotten, the division engineer for the Colorado Division of Water Resources in the basin, told the roundtable Tuesday at its monthly meeting in Alamosa, just a few blocks from the river. “I’m sure we’re going to dry up the Conejos (River) and maybe the Rio Grande, in some spots.”

Cotten shared snowpack data taken from snow telemetry, or SNOTEL sites, around Colorado, which measure the amount, and weight, of the snowpack at specific locations around the state.

The data this week showed a decline in snowpack from north to south in Colorado.

The North Platte River basin, to the northeast of Steamboat Springs, was at 102 percent of the median level for that date.

The South Platte River basin, which includes Denver, was at 93 percent.

The Yampa and White river basins, north of Interstate-70, were at 89 percent.

The Colorado River basin, which includes Glenwood Springs and Aspen, was at 86 percent.

The Gunnison River basin, further south, was at 60 percent.

The Rio Grande River basin was at 40 percent.

And the San Miguel, Dolores, Animas and San Juan river basin, in the southwest corner of the state, was at 39 percent.

So while water managers and river users in the northern and eastern part of the state may have more water than their southern counterparts, it’s a bit like passengers in a lifeboat having more drinking water in their end of the boat than the passengers in the other end — it’s nothing to gloat about.

Jeff Derry is the executive director of the Center for Snow and Avalanche Studies in Silverton, which studies the “dust on snow” phenomenon and how it affects the state’s snowpack.

Derry focuses on information from “snow course” sites, in addition to SNOTEL sites, as the snow course sites measure the snow water equivalent, or moisture levels in the snow, across broader landscape areas and have often done so over longer periods of time than SNOTEL sites.

He showed the roundtable graphs that indicate the snowpack in the southern part of the state, as of April 1, was tracking right at the same level as the very dry years of 1977 and 2002, while the whole of the state, on average, was tracking just above those drastically low years.

The avalanche center’s website has a graph that takes the average of 81 snow course sites across Colorado.

“Water year 2018 is comparable to 1966, 1981, 1999, 2004, (and) 2012,” Derry wrote. “We are faring just very slightly better than 1977 and 2002.”

Derry’s graphs also included long-term trend lines dating back 30 to 80 years, which clearly indicate Colorado’s snowpack has been shrinking and temperatures have been rising, especially on the colder end of the spectrum, meaning the lowest temperatures in winter are not as low as they used to be, especially over the past 30 years.

“It’s getting warmer and we’re seeing less precipitation in the wintertime,” Derry told the roundtable members.

Aspen Journalism is covering rivers and water in collaboration with The Aspen Times. More at http://www.aspenjournalism.org.

From The Grand Junction Daily Sentinel (Dennis Webb):

State weather experts say the snowpack in the Gunnison River Basin and farther south will likely melt out a month earlier than normal this spring even as snow levels farther north continue to fare better, thanks in part to a recent storm.

“Things are getting better in the areas that are just slightly below normal, and still getting worse in the areas that are way below normal,” Peter Goble, climatologist and drought specialist at the Colorado Climate Center, said Tuesday in a webinar on drought conditions.

The update came at a time when snowpack levels in river basins typically reach their peaks and spring runoff begins. Assistant State Climatologist Becky Bolinger said the San Juan River Basin area in southwest Colorado already likely has peaked at 50 percent of normal seasonal peak accumulation, and the Gunnison basin, which is at 58 percent of seasonal median peak, also may have peaked…

She said the same goes for the San Juan area, while Goble said the Upper Rio Grande Basin is melting out even faster. He said he recently visited southern Colorado and the snowpack looked “heartbreaking” in the San Juan area and “pretty miserable” in the Sangre de Cristo mountains.

Many snow-measurement sites are recording the lowest snowpacks on record in southern Colorado. Sites on Grand Mesa are showing snowpacks at less than half of average, and at or near record low levels.

Meanwhile, the storm that hit northern Colorado watersheds several days ago brought up to 2½ feet of snow, the Colorado Climate Center says. In terms of water content, Bolinger said the storm brought two to three inches of precipitation to some higher-elevation areas and more widespread precipitation ranging from a half-inch to an inch.

Yampa River Basin snowpack is at 80 percent of seasonal peak levels, and the Upper Colorado River Basin in Colorado is at 77 percent of peak. Bolinger hopes to see more accumulation in the Upper Colorado Basin, but she said peak accumulation there usually arrives by mid-April…

Colorado’s statewide snowpack was at 72 percent of median Tuesday, up from 68 percent at the start of the month. The snowpack is now where it stood March 1 before falling due to March precipitation that was only 65 percent of normal, according to the Natural Resources Conservation Service.

Some streams already are running below average levels, and the NRCS said last week that spring and summer streamflows in Colorado will be between 30 and 70 percent of normal.

It said the Gunnison River at Grand Junction is forecast to have only 33 percent of average streamflow, and the Colorado River at Cameo is expected to flow at 64 percent of average. The Gunnison’s flow will be affected by the U.S. Bureau of Reclamation’s efforts to hold back as much water as it can in Blue Mesa Reservoir, which it expects will fill to about three-quarters of capacity.

Goble said while it doesn’t appear that McPhee Reservoir in southwest Colorado will fill this year, it sounds like farmers in the Four Corners area are being promised their full irrigation allotment. While the reservoir may be drawn down some this year, “we’re not in miserable shape there,” he said.

Reservoir storage that is at 114 percent of average statewide and is above average even in southwestern Colorado continues to ease the sting of this winter’s poor snowfall. Bolinger said she’s not hearing a huge concern from water providers this year…

She said areas that rely only on streamflow will have more of a concern, as will growers of some dryland crops.

She said water officials will be watching how much reservoir levels can be built up this spring. Southern reservoirs aren’t likely to be able to store additional water due to low runoff and increased drawing down due to drought. That will mean that next winter a more normal snowpack will be needed to help those reservoir levels recover.

If next winter is similar to this year, “that’s when we’re really looking at having to make some hard decisions … and really feeling the effects of drought,” she said.

From The Vail Daily (Scott Miller):

A heavy storm last weekend did more than put smiles on the faces of local powder hounds. That storm, by itself, put down 18 percent of Vail Mountain’s current snowpack.

According to the vail.com website, Vail Mountain has received 23 inches of snow in the past seven days, virtually all of it from that weekend storm.

Elsewhere on Vail Mountain, the U.S. Department of Agriculture’s snow-measurement site recorded 14.6 inches of “snow water equivalent,” enough to finally surpass the record-low snow season of 2011-12.

Still, the site is recording a total well below the 30-year median — just 70 percent.

The news is better at the measurement sites at Copper Mountain and Fremont Pass. Those sites are the closest ones to the headwaters of Gore Creek and the Eagle River, respectively.

At Copper Mountain, the measurement site is at 95 percent of the 30-year average. At Fremont Pass, the total is 111 percent of average…

Last weekend’s storms were still more than welcome. [Peter] Goble called the storm a “game-changer” in terms of snowpack. While snowpack is still well below normal through most of the state, Goble said the next drought map from his office will have some changes. Locally, some of the areas in Eagle County will drop back one level in its classification. Areas that most recently were in “severe” drought will drop back to “moderate,” while the area around Vail may revert to the lowest classification, “abnormally dry.”

From The Craig Daily Press (Eleanor C. Hasenbeck):

As of April 10, snowpack in the Yampa and White River Basin was at 89 percent of normal, which is nearly the highest it’s been this water year, said National Weather Service meteorologist Jeff Colton. To the north, Wyoming’s Green River Basin is at 91 percent of median.

The Stagecoach, Elkhead and Yamcolo Reservoirs are expected to fill or nearly fill…

Now, timing is key. Availability of water through the course of the season is dependent on the timing and amount of spring precipitation and melting snowpack.

Currently, water managers are bypassing water from rain and snowmelt through Stagecoach Reservoir, because it can’t be filled until the ice on top of the water has melted; ice flowing through the dam’s spillway would damage the infrastructure of the reservoir.

On the Yampa, managers don’t want to see too much too soon. Gray said the Yampa typically hits the high water mark around June 1 in Moffat County…

As long as the area gets more spring moisture — and warm temperatures don’t melt snowpack in the Park Mountains too early — Gray said irrigation in the area is expected to be “a little short,” but water is not anticipated to be as scarce as it appeared it might be earlier this year…

For now, Northwest Colorado still faces drought conditions, according to the United States Drought Monitor. The eastern half of the county and a sliver in the northwest corner of the county are in abnormally dry conditions. Most of western Moffat County is in a moderate drought, while the Dinosaur and Massadona areas face severe drought conditions.

Gila River watershed. Graphic credit: Wikimedia

From the Arizona Department of Natural Resources:

Not without good reason, the nation’s media have been focusing on the dramatically thin snowpack of the Upper Colorado River Basin, which portends a meager amount of runoff into the Colorado River system.

As of April 2, the basin snowpack stood at just 72 percent of normal, heralding a runoff season that may be the sixth driest in the 55 years that Glen Canyon Dam and Lake Powell have been in place to capture the runoff.

On average, the in-flow into Lake Powell is 7.1 million acre-feet per season. Although the figure may change, this year’s projection currently stands at less than half that amount – 3.1 million acre-feet.

Bad news? Oh, yes. But where Arizona’s renewable water supplies are concerned, the 2018 story gets still worse. As opposed to the Colorado River system, the in-state river systems are setting records.

The Salt River Project is reporting that, according to provisional data for runoff in the Salt and Verde reservoir systems, the January – March runoff totals are “the lowest amounts on record dating back to 1913.”

Water Year precipitation for the State’s two major watersheds (Oct. 1 – Mar. 31) stood at just 2.88 inches, a figure that unsurprisingly graded out as “Well Below Normal.”

As a result, runoff in the watershed has been extremely poor. SRP data indicate that runoff into the Salt and Verde reservoirs in March stood at just 14 percent of median – the second-lowest amount on record.

In the wake of a December – February snowpack season that produced next to nothing in the two Arizona watersheds, three small storms after mid-March produced a snow-water equivalent of just 22,000 acre-feet, most of it at the highest elevations of the region.

Overall, total watershed streamflow this runoff season (January -May) is forecast to be near the lowest on record, which stood at 106,000 acre-feet in 2002.

SNOTEL data produced by the Natural Resource Conservation Service depict snowpack values as high as 40 percent of normal and as low as zero percent of normal.

If you seek to frolic in the snow in Arizona, you’ll be hard-pressed to find white stuff for your skis: According to satellite data, just 0.3 percent of the watershed had snow coverage as of April 1.

If winter in Arizona proved dry, early spring doesn’t hold out much hope for moisture here, either. Reports indicate that Arizona should anticipate warmer, drier weather through the first half of April, at least.

From The Mohave Daily News:

Forty-five percent of Arizona is now in extreme drought according to the Arizona Drought Monitoring Technical Committee.

The committee released a report last week showing statewide drought conditions worsened during March. The continued dryness led to drought declarations on the Navajo Nation and in Yuma County.

Though a series of weak storms passed through Arizona, they left only insignificant snow, according to the report. The southern half of the state remained dry and northern Arizona received only scattered light precipitation. The committee noted rangeland conditions are very poor with little forage, and water hauling for both livestock and wildlife has begun in many parts of the state…

U.S. Bureau of Reclamation reports as of Tuesday showed Lake Powell is 56 percent full and Lake Mead is at 41 percent, with an 1,087 foot elevation, roughly 12 feet above the 1,075 elevation that would trigger automatic first tier shortages for Central Arizona Project deliveries.

BuRec does not anticipate any level of shortage in Lake Mead for 2018, but increased the probability of shortage in 2019 from 15 percent in August 2017 to 17 percent probability now. BuRec’s Colorado River Simulation System model also increased the probability of shortage in 2020 by 7 percent, in 2021 by 13 percent and in 2022 by 11 percent.

Worse, ADWR officials said, in-state river systems are historically low; provisional data for runoff in the Salt and Verde reservoir systems show the January through March runoff totals are “the lowest amounts on record dating back to 1913.”

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