Snowpack news: Storm expected to start Friday in the mountains should boost snowpack

Westwide SNOTEL snow water equivalent as a percent of normal February 18, 2015
Westwide SNOTEL snow water equivalent as a percent of normal February 18, 2015

From CBS Denver (Ed Greene):

Clouds begin to increase [today] in advance of a major weather change on Friday with rain developing by late evening, then quickly changing over to snow. Snow will be heavy early Saturday, decreasing in intensity Saturday afternoon but continuing into Sunday with much colder highs: upper 20s Saturday, low 20s Sunday. By Monday morning there could be up to a foot of snow on the ground in parts of the greater metro area with the temperatures only in the single digits making for a very difficult Monday morning rush hour.

From the Associated Press (Dan Elliott) via The Albuequerque Journal:

Snowpack in the mountain valleys where the Colorado River originates was only a little below normal on Wednesday, marking one of the few bright spots in an increasingly grim drought gripping much of the West.

Measurement stations in western Colorado showed the snowpack at 90 percent of the long-term average.

By contrast, reporting stations in the Sierra Nevada range in drought-stricken California showed snowpack at 50 percent or less in early February, the most recent figures available. Some detected no snow at all.

Mountain snow in Colorado is closely monitored because a half-dozen Western waterways, including the 1,400-mile Colorado River, start in the area. The river and its tributaries supply water to millions of people in seven states and Mexico.

Much of the river comes from mountain snow that accumulates during winter and melts in the spring…

In the Pacific Northwest, warm temperatures have brought rain instead of snow, so the mountains aren’t accumulating snowpack for the spring runoff, when farmers and water managers need water to irrigate crops and refill reservoirs.

Snow accumulation in the Rocky Mountains in Colorado, Wyoming and Montana has been relatively good. Snowpack in the Colorado valleys that feed the east-flowing South Platte River were at 102 percent of average.

“Not spectacular, but not miserable, either,” Strobel said.

Even in Colorado, the picture is mixed. Statewide, including the Colorado River, the South Platte and six other basins, the snowpack stands at 78 percent of normal, with the parched southwest corner at 56 percent.

It would take half again the normal amount of snowfall between now and April to bring the statewide snowpack up to average, said Brian Domonkos, who supervises the snow survey in Colorado.

The Colorado River Basin isn’t accumulating snow as quickly as it was earlier in the season, Domonkos said Wednesday at a meeting of the state Water Availability Task Force, which monitors drought conditions.

“It’s been pretty dry since about the beginning of February,” he said.

The Colorado update came after calls for increased multi-state cooperation in the Colorado River basin due to the prolonged drought. The basin is home to 40 million people and 4 million acres of farmland.

Lake Mead in Nevada is the key measuring point of water in the Colorado River system, which also includes the Green, San Juan and Gila rivers and some 55 dams and diversions. The lake dropped to historic levels last year after almost 15 years of regional drought.

Las Vegas, with 2 million residents and 40 million visitors a year, gets 90 percent of its drinking water from Lake Mead. The U.S. Agriculture Department has declared most of Nevada a natural disaster area due to the drought.

From The Greeley Tribune (Kayla Young):

A dry spell starting in late December and carrying through January has compromised Colorado’s snowpack and diminished a once promising water supply outlook, according to the Natural Resources Conservation Service.

SNOTEL data indicates this past January was the driest on record in 28 years in the Colorado mountains.

Overall, January brought just 1.4 inches of mountain precipitation, 45 percent of the average. January typically brings an average of 3.1 inches of mountain precipitation, ranking the month as the fourth most important for precipitation in the year.

The South Platte had the greatest precipitation totals statewide, reaching 62 percent of average.

“With nearly one third of the winter gone, Colorado is running short of time to catch up,” said Brian Domonkos, Colorado Snow Survey supervisor, in a press release. “Statewide, snowfall would need to amount to 124 percent of normal snowfall from now ‘til mid-April to achieve normal snowpack peak levels.”

From The Pueblo Chieftain (Matt Hildner):

There are few silver linings with a snowpack as poor as the one now sitting at the headwaters of the Rio Grande River.

But Division Engineer Craig Cotten said recent warm temperatures in the San Luis Valley have not prompted much runoff from the basin’s high country, where snowpack was at 65 percent of average at the beginning of the month.

“We’re still pretty steady, about where we usually are,” he said.

Still, the existing snowpack does not bode well for irrigators come springtime.

The Natural Resources Conservation Service has forecast a flow of 457,000 acre-feet on the Rio Grande, which is 70 percent of average.

The forecast for the Conejos River is about 210,000 acre-feet, which would be about 60 percent of average.

“So, not great at this point,” Cotten said.

The Conejos and the Rio Grande are the two rivers in the valley with obligations to send water downstream to satisfy an interstate compact with New Mexico and Texas.

If the projections hold, the Rio Grande would be required to send 110,000 acre-feet downstream, while the Conejos would be obligated to send 51,000 acre-feet.

But the warm weather has prompted several requests to move up the irrigation season from its typical beginning in April.

Cotten said February is too early to consider such requests but they’ll get a closer look in March.

As the water year progresses, Cotten’s office also will begin using a new stream forecasting service from the National Weather Service.

The information from the weather service would predict flows on the Rio Grande, Conejos, San Antonio and Los Pinos rivers, the latter two of which are tributaries of the Conejos.

Last year, water officials from around the valley said inaccuracies with the NRCS’ snowpack measurement and forecasting services made it difficult to meet the requirements of irrigators while also sending the required amount of water downstream to satisfy the compact.

The weather service’s forecast will provide multiple scenarios and be used in conjunction with the one normally issued by the NRCS.

“Hopefully, they’ll be very close and fairly similar,” he said. “If not we’ll have to have some discussion and see what’s going on.”

From Arizona Public Radio (Vanessa Barchfield):

This winter’s snow pack in the Colorado Rockies is slightly below average, a relatively good sign for states, including Arizona, that use Colorado River Water.

Measurements taken in the mountain valleys of western Colorado, where the Colorado River originates, put snow pack at 90 percent of the long-term average. Officials from the U.S. Department of Agriculture, which runs the snow survey, said that’s not spectacular – but not miserable either.

Mountain snow in Colorado is closely tracked because when it melts it feeds the Colorado River, which provides water to seven states, including Arizona.

Snow pack in other parts of the West is not looking as good as in Colorado.

The last measurement taken in the Sierra Nevada range put snow pack at 50 percent or less. There was no snow at all at several measurement stations.

And in the Pacific Northwest, warm temperatures have brought rain instead of snow, which means there won’t be much water to refill reservoirs with come spring.

Other than Colorado, not spectacular but not miserable levels of snow pack have been measured in Montana and Wyoming as well.

Click on a thumbnail graphic to view a gallery of snowpack data from the Natural Resources Conservation Service.

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