Low snowpack affects future water supply

Washington State snowpack is melting earlier than usual, according to data from the fourth 2015 forecast by the United States Department of Agriculture’s Natural Resources Conservation Service.

“Seventy-four percent of our long-term monitoring sites have set new record low snowpack,” said the organization’s Water Supply Specialist, Scott Pattee. “March was warm and dry in most of the West; as a result, snow is melting earlier than usual.”

Historically, April 1 is the peak in terms of snowpack. This year, the peak came earlier. The April 1 statewide readings were 22 percent of normal, shattering the previous record low of thirty-three set in 2005.

“The only holdout is in the Methow River Basin, which is reporting 79 percent of normal,” said Pattee. “Look at the data and you’ll see that almost everywhere else is at 50 percent or less of normal readings.”

A consequence of the early snowmelt is that Western states will have reduced streamflow later this spring and summer.

In Western states where snowmelt accounts for the majority of seasonal water supply, information about snowpack serves as an indicator of future water availability. Streamflow in the West consists largely of accumulated mountain snow that melts and flows into streams as temperatures warm in spring and summer. National Water and Climate Center scientists analyze the snowpack, precipitation, air temperature and other measurements taken from remote sites to develop the water supply forecasts.

The Service monitors conditions year-round and will continue to issue monthly forecasts until June. The water supply forecast is part of several USDA efforts to improve public awareness and manage the impacts of climate change, including drought and other extreme weather events. Through the creation of the National Drought Resilience Partnership, launched as part of the President’s Climate Action Plan, federal agencies are working closely with states, tribes and local governments to develop a coordinated response to drought.

Since 1939, USDA has conducted snow surveys and issued regular water supply forecasts. Other resources on drought include the U.S. Drought Monitor. For information on USDA’s drought efforts, visit USDA Disaster and Drought Information. And to learn more about how Natural Resources Conservation Service is helping private landowners deal with drought, visit http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/newsroom/features/?cid=stelprdb1245689.