Summer runoff forecast looks to be above-average
By Ann McCreary
The new year began with a typical La Niña weather pattern, producing warm, wet conditions across Washington state, but comparatively cooler temperatures in the Methow Valley helped contribute to a healthy early winter snowpack.
The jet stream is stationed this week over the mid-Cascades, said Scott Pattee, water supply specialist with the Natural Resources Conservation Service. That means precipitation is likely to come as snow in the northern part of the state, but rain in the southern part.
Snowpack in the Methow River basin was at 124 percent of normal as of Jan. 9, compared to 100 percent of normal at the same time last year. Only the Nooksack River basin had a higher snowpack, at 139 percent.
Snowpack readings at the Hart’s Pass SNOTEL (snow telemetry) site was 122 percent of average on Jan. 16, compared to 113 percent of average on that date last year.
Snowpack readings around the state were at 95 percent of normal on Jan. 1, slightly lower than last year, Pattee said. The lowest readings were at 64 percent of normal in the Walla Walla and Green river basins.
Precipitation in December was near normal overall, with the Upper Columbia basin, which includes the Methow Valley, at 109 percent of normal, Pattee said. Precipitation for the water year, which runs Oct. 1 – Sept.30, is 106 percent of average for the Upper Columbia Basin.
Summer runoff forecast for the Methow River is 109 percent of average, and December streamflow was 110 percent of average.
Temperatures in the Upper Columbia river basin were near normal for December, but slightly below normal for the water year.
“The National Weather Service three-month forecast indicates below-normal temperatures and above-normal precipitation,” Pattee said. That might help some of the areas in the southern part of the state that need more snow to bolster their snowpack, he said.