Across the Western U.S., snowpack has melted sooner than usual, according to data from the fourth 2015 forecast by the United States Department of Agriculture’s Natural Resources Conservation Service (NRCS).
“Almost all of the West Coast continues to have a record low snowpack,” NRCS Hydrologist David Garen says. “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 snowpack. This year, the peak came earlier. There was little snow accumulation in March, and much of the existing snow has already melted.
“The only holdouts are higher elevations in the Rockies,” Garen says. “Look at the map and you’ll see that almost everywhere else is red.” Red indicates less than half of the normal snowpack remains.
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.
NRCS 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 NRCS is helping private landowners deal with drought, visit the NRCS’ drought resources.