#Runoff/#Snowpack news: Dry Conditions, Accelerated Snowmelt Reported Across #Colorado — CBS 4 Denver

From CBS 4 Denver (Audra Streetman):

The Natural Resources Conservation Service reported below average precipitation in major Colorado basins during the months of April and May. Officials said the combination of low precipitation and warm temperatures have caused accelerated snowmelt across the state.

The snowmelt is particularly fast in southern Colorado, which has seen the least amount of precipitation. According to NRCS, recent conditions, combined with a dry late summer and fall last year, have led to an unusual relationship between snowpack and snowmelt runoff volumes….

Across Colorado, 49 out of 115 Colorado SNOTEL sites received the lowest or second lowest precipitation amounts on record for the combined months of April and May. Colorado mountains have also had warmer than normal temperatures. Officials said this combination has led to faster than usual snowmelt rates.

Streamflow forecasts in all major Colorado basins are below normal volumes, but officials say there are notable differences between northern and southern basins.

The North Platte, South Platte, and Colorado basins have the highest streamflow forecast values, ranging on average from 72 to 79 percent of normal volumes. The lowest streamflow forecasts are in the state are in the Rio Grande basin where they average to be a meager 41 percent of normal.

Officials said statewide reservoir storage is currently at 100 percent of average but varies considerably basin to basin. The largest storage in the state is in the combined Yampa and White basins as well as the Colorado basin where there is 115 percent of average storage.

On the low end, the Rio Grande basin only has 62 percent of average storage. Officials say this could pose water resource challenges considering the low streamflow forecasts.

Snow-dusted Gore Range in Colorado, photographed from the air.

From The Vail Daily (Scott N. Miller):

While local streams are currently running fast and high, this season’s streamflow seems to have hit an early peak.

That peak has been driven in large part by an early melt-off of local snowpack.

According to data from the Eagle River Water & Sanitation District, Vail Mountain’s snowpack, as measured in snow water equivalent, melted off May 20, more than two weeks earlier than normal.

While the snowpack at Copper Mountain ran above the 30-year median this season, that site — the closest to the headwaters of Gore Creek — has also melted off. With the extra snow this year, that site melted off June 5. That site usually melts off by May 30.

There’s still snow on the Fremont Pass site — the closest site to the Eagle River’s headwaters. That site also had above-average snowfall over the winter…

Streamflows are also peaking early, and stronger than normal in some cases.

Gore Creek above Sandstone Creek peaked June 1 at 998 cubic feet per second. The usual peak of 792 cubic feet per second generally comes on June 5.

The Eagle River measurement site near the wastewater treatment plant at Avon also peaked at a higher than normal flow on June 2. The normal peak comes June 6…

West Drought Monitor June 2, 2020.

Assistant State Climatologist Becky Bolinger of the Colorado Climate Center at Colorado State University wrote in an email that drought conditions “could persist or worsen until the start of the monsoon. If there is not a strong start to the monsoon or if it doesn’t extend far enough north this summer, western Colorado and the Four Corners could really be hurting by the (end of September).”

With a chance for above-average summer temperatures it’s likely the state’s drought conditions will worsen. At the moment, all of Eagle County is in either “abnormally dry” or “moderate drought” conditions. Most of the state is in some form of drought, with the southern part of the state the hardest-hit.

In the valley, that means residents need to be careful with water use, particularly outdoor water use. While almost all indoor use ends up being returned to streams, very little outdoor water use ends up back in the river. That can hurt streamflows and aquatic life.

“If you care about local streams … be as efficient as you can,” Johnson said.

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