The latest #ColoradoRiver streamflow forecast is hot off the presses #COriver

Nearly the full length of Lake Powell on the Colorado River in southern Utah and northern Arizona is visible in this photograph shot by an astronaut aboard the International Space Station, on Sept. 6, 2016. The view is toward the southwest. Water flow is from the lower right toward the top. (Source: NASA Earth Observatory)

From the US Bureau of Reclamation:

Current runoff projections into Lake Powell are provided by the National Weather Service’s Colorado Basin River Forecast Center and are as follows: Observed unregulated inflow into Lake Powell for the month of December was 0.299 maf or 82 percent of the 30-year average from 1981 to 2010. The forecast for January unregulated inflow into Lake Powell is 0.310 maf or 86 percent of the 30-year average. The forecasted 2018 April through July unregulated inflow is 3.900 maf or 54 percent of average.
In this study, the calendar year 2018 diversion for Metropolitan Water District of Southern California (MWD) is forecasted to be 0.732 maf. The calendar year 2018 diversion for the Central Arizona Project (CAP) is forecasted to be 1.574 maf. Consumptive use for Nevada above Hoover (SNWP Use) is forecasted to be 0.290 maf for calendar year 2018.

Due to changing Lake Mead elevations, Hoover’s generator capacity is adjusted based on estimated effective capacity and plant availability. The estimated effective capacity is based on projected Lake Mead elevations. Unit capacity tests will be performed as the lake elevation changes. This study reflects these changes in the projections.

Hoover, Davis, and Parker historical gross energy figures come from PO&M reports provided by the Lower Colorado Region’s Power Management Office, Bureau of Reclamation, Boulder City, Nevada. Questions regarding these historical energy numbers can be directed to Eric Carty at (702) 293-8129.

Note: John Fleck warns about the “error bars” around a forecast this early in the season.

Improving forecasts goal of research effort by Fort Lewis College biologist and others across the west

Graphic credit: American Rivers

From The Durango Herald (Mary Shinn):

Researchers are working to predict water flow in the Western United States – in the same way meteorologists predict weather – to help cities, ranchers and emergency managers make crucial decisions about water management in a changing climate.

The work is focused on forecasting the quality and quantity of water flowing into rivers from mountainous areas, said Heidi Steltzer, an associate professor of biology at Fort Lewis College and an executive committee member working on the project.

Forecasts will make short-term and long-term predictions – from what will happen in one day, in a month or annually – for watersheds across the Western U.S. and beyond, she said.

“You could bring (the model) to the Animas River Valley, you could run the model and we could do a better job managing for water,” she said.

The forecasts could provide better answers to questions such as: “How much water is going to be available for agriculture? Do cities have the water they need? … Do species that live in and around the water corridors have the water they need?” Steltzer said.

Researchers aren’t looking to make predictions hundreds of years into the future, but they want to make accurate predictions as the environment and the system change over time, she said.

For example, they are working to understand the effect snow melting earlier in the year has on the watershed system.

The predictions will also assess what water is bringing down from the mountains, such as nutrients, dissolved salt, dissolved organic carbon and metals. Better water-quality data will help water-treatment managers make long-term decisions about what equipment is needed to treat water to preserve the taste or perhaps strip out certain metals, such as cadmium, said Kenneth Williams, deputy lead and chief field scientist for the project.

The multimillion-dollar project received its funding from the U.S. Department of Energy in October 2016. Researchers are working in the Elk Mountains near Crested Butte, where they plan to collect data in four watersheds. The project’s federal funding will be reviewed every three years, and there is no predetermined end date, Williams said.

Interview with Andy Wood — S2S Climate Outlooks for Watersheds

From Water Deeply (Matt Weiser):

Understanding watersheds is vital to tracking environmental conditions and water availability. Now there’s a web-based tool that offers temperature and precipitation forecasts at the watershed level, says scientist Andy Wood.

ANYONE WHO TRACKS the weather closely soon becomes aware of a surprising fact: it’s not easy to get a forecast tailored to your local watershed – perhaps the most important natural terrain feature that determines water supply, water quality and flood risk.

In the United States, most weather forecasts pay no attention to watersheds. Instead, predictions are made within broad “climate divisions” that do not necessarily recognize the finer scale of watersheds. The National Weather Service (NWS) does have a network of river forecast centers, mainly to provide vital streamflow predictions. These are mostly aimed at a technical audience and do not break out information by watershed.

Now there is a new tool to fill this forecast gap. A partnership between the National Center for Atmospheric Research (NCAR) and the University of Colorado Boulder has produced a forecasting website that offers real-time weather prediction maps based on watershed boundaries across the nation.

Not only is the new system watershed-based but it also offers temperature and precipitation forecasts up to a month ahead. That is well beyond conventional forecasts offered by the NWS.

Known as S2S Climate Outlooks for Watersheds, the system is still considered a prototype. But it has already begun to fill an important need by applying weather and climate data to watersheds. Water Deeply recently spoke to Andy Wood, a project scientist at the NCAR and co-leader of the project, who explained how the system was developed and how it can be used.

Wood emphasized he is eager to hear feedback from users (via this form) about how to improve this new tool.

Photo credit UCAR/NCAR

Water Deeply: Why did you want to bring forecasting to the watershed level?

Andy Wood: This is something I’ve been interested in doing for a while. I used to work for NOAA [the National Oceanic and Atmospheric Administration] in two different river forecast centers: in Salt Lake City for the Colorado Basin, the other in Portland for the Northwest region. As somebody who looked at climate forecasts in that context, it always struck me that it would be nice to have it communicated on a spatial basis, but connected a little more strongly with the kind of modeling and analysis that we would do for river forecasting. And one major basis for that is watersheds and watershed scale.

For instance, if you manage water in the Yakima Basin [in Washington state], you would be able to find information that’s kind of tailored to that watershed. So it’s a pretty simple concept, in a way.

#Snowpack Near Record Lows Spells Trouble for Western Water Supplies — Inside Climate News #ColoradoRiver #COriver

Westwide SNOTEL basin-filled map January 15, 2018 via the NRCS.

From Inside Climate News (Bob Berwyn):

Scientists say snow seasons like the U.S. West is experiencing now will become more common as global temperatures rise, and economic costs will go up, as well.

Months of exceptionally warm weather and an early winter snow drought across big swaths of the West have left the snowpack at record-low levels in parts of the Central and Southern Rockies, raising concerns about water shortages and economic damage.

Drought spread across large parts of the Western United States this month, and storms that moved across the region in early January made up only a small part of the deficit. Runoff from melting snow is now projected to be less than 50 percent of average in key river basins in the central and southern Rockies.

Most of the region’s annual water cycle starts as thick layers of mountain snow that accumulate during winter and melt slowly in spring. If the snows don’t come, there’s no water to fill the reservoirs.

A series of recent studies examines how vulnerable that snowpack is to rising temperatures, and how the economic costs from the declining snowpack could soar into the hundreds of billions of dollars.

From the Associated Press via Steamboat Today:

Aspen Skiing Co. said snowfall has improved recently, with up to 17 inches falling in the past week. Storms last week allowed Aspen to open more terrain.

Colorado Ski Country USA noted the state’s historically snowiest months are still ahead.

Snowpack in the Colorado mountains ranged from 34 percent to 84 percent of the long-term average on Sunday, with the southwestern corner of the state hardest hit.

Drought conditions have spread across virtually all of Colorado, according to the U.S. Drought Monitor, a federal agency that tracks conditions nationwide.

West Drought Monitor January 9, 2018.

From The Rio Blanco Herald-Times (Jennifer Hill):

The first two weeks of 2018 have seen a continuation of dry weather as the local region plunges further into drought-like conditions.

According to the National Integrated Drought Information System, the western half of Rio Blanco County is currently experiencing Moderate Drought conditions with less than 30 percent of normal precipitation. The Eastern side of the county is considered Abnormally Dry.

The Colorado Snow Survey lists Rio Blanco County at 66 percent of normal snow pack.

The dry weather has put pressure on area ranchers as they are forced to continue hauling water to livestock that would normally lick snow. Jon Hill, owner of the Cripple Cowboy Cow Outfit, expressed concerns about the health impact of the extra dust in the air on the livestock. He’s also worried about the long term ability of area wells and springs and what the spring and summer grasses will be like without enough running water. But it’s not just his ranch that Hill is concerned about. “The bigger issue isn’t just one ranch,” he said. “This could impact the Colorado River Compact.”

[…]

Gary Moyer, vice president of the White River Conservation District, is hopeful that some much needed moisture will soon arrive and alleviate concerns about a lack of moisture in the soil. “We are all holding our breath,” he said. “It could change rapidly in the coming months.”

According to the Climate Prediction Center organized by the National Oceanic and Atmospheric Administration, or NOAA, the next three months are likely to bring the possibility of near normal precipitation to the county coupled with above normal temperatures. Jim Pringle with Grand Junction NOAA Office said the weather is currently tracking normal for a La Nina pattern which typically brings the storm track to the northern states and drier weather to the south. An El Nino year tracks the opposite with precipitation to the south and dry weather in the north.

The dry start to winter is not unheard of. One hundred years ago the Meeker Herald reported very similar conditions of little to no snow and concerns that there wouldn’t be any ice to cut. However, the mostly anecdotal historical record may provide some hope. If the weather cycle continues to follow the pattern of 1918, we’ll have snow by the end of the month.

From The Denver Business Journal (Ben Miller):

The 2017-2018 ski season isn’t starting very well for Vail Resorts Inc.

The Broomfield ski resort operator (NYSE: MTN) said total skier visits to its North American ski resorts were down nearly 11 percent compared with a year earlier.

That’s not all that’s down this season: Vail said ski school revenue was down 4.5 percent, dining revenue was down 8.7 percent, and retail/rental revenue was down 11.5 percent compared with last season.