#Snowpack news: #Colorado needs 139% of normal precipitation to hit the normal peak, thanks La Niña

Statewide snowpack January 9, 2018 via the NRCS.

Here’s a snowpack measurement primer from Cory Reppenhagen writing for 9News.com:

Light snow fell Tuesday morning as a crew from the Natural Resources Conservation Service trekked into the Colorado backcountry to conduct a snowpack survey, or what they call a snow course.

“We are strictly the data providers. We collect, provide and analyze the best data we possible can,” said Karl Wetlaufer, an NRCS hydrologist.

That data is very important for state water managers trying to plan for how much water will be available in the coming years. Eighty percent of Colorado’s water comes from snowpack.

That is how much water you would end up with if all the snow was melted.

“Generally, 7 inches of SWE is what I was expecting, and under the tree canopy it will be a little less,” Wetlaufer said.

That’s not too bad for that location on Berthoud Pass, which is at 78 percent of average, but it really shows you how bad things really are down to our south.

“Southwest Colorado is extremely dry. Where a lot of these sites would normally have say, in the range of 7 inches of snow water equivalent, they have like 1.2 (inches),” Wetlaufer said.

NRCS can’t do manned surveys too often, so that is where automated snow telemetry, or Snowtel sites come in.

One hundred and fifteen of these sites across Colorado measure and report snow depth and snow-water equivalent every day. That is how we get those snowpack graphics that you often see published on 9NEWS…

We’ve heard no panic from state water managers yet because we have plenty of water stored in our reservoirs across the entire state.

The peak of snowpack in Colorado is usually about the middle of April, so there is still time to make up some ground, but the La Niña weather pattern, which is getting most of the blame for our dry season, is forecast to remain in place into the spring time.

Karl Wetlaufer (NRCS), explaining the use of a Federal Snow Sampler, SnowEx, February 17, 2017.

From CBS Denver (Matt Kroschel):

The northern mountains are holding more snow than those of the southern half of the state with the South Platte basin. That’s where CBS4 toured Tuesday, which has the most at 83 percent of median.

Alternatively, the combined San Miguel, Dolores, Animas, and San Juan basins are the lowest with a meager 21 percent of normal.

“While there is still a lot of Winter left we would need to receive well above average precipitation for the rest of the season to achieve a normal peak snow accumulation, especially in southern Colorado,” Wetlaufer said.

Westwide SNOTEL basin-filled map January 8, 2018 via the NRCS.

From Outside Magazine (Grayson Schaffer):

As the East gets pummeled by winter storm (cough!) Grayson, a so-called bomb cyclone, and the President issues dumb tweets about global warming, it’s worth noting that ski areas in the central and southern Rockies are having the driest year in recent memory.

“The official numbers show ten to 20 percent of average snowpack,” says Joel Gratz, founding meteorologist at Boulder, Colorado-based OpenSnow, which offers forecasts for skiers. “There’s no way to sugar coat it. There’s just not a lot of snow on the ground.”

Just how dry has this winter been? According to Gratz, automated Snotel measurements done by the USDA have only been in place since the nineteen-seventies. But current conditions from roughly the I-70 corridor—which runs east to west from the main Colorado ski resorts through the Front Range—and south match or exceed the lowest snowpack Snotel levels ever recorded. “It could be the low end since the fifties or sixties,” Gratz speculates.

Brian Lazar, the deputy director of the Colorado Avalanche Information Center, based in Carbondale, notes that the snowpack in southwestern Colorado is especially grim. “Statewide snowpack in Colorado is just over 50 percent of where we should be at this time of year,” says Lazar. “December was one of the driest snowfall months on record. But the southern mountains are doing even worse than that. It gets progressively worse as you move south.”

There are some bright spots, though. Arapahoe Basin and Breckenridge, closer to the Continental Divide along I-70, have nearly 90 percent of their usual snowpack. Farther north, from northern Washington across northern Idaho and into western Montana, snowfall is above average. And British Columbia is its usual snowy self.

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