Above-normal readings bode well for water release
By Ann McCreary
Although winter is more than half over and snow is receding in the Methow Valley, snowpack is holding up well in mountains surrounding the valley and throughout Washington, unlike areas further south in the Pacific Northwest.
“With 60 percent or more of the winter gone, Washington state has managed to hold on to a respectable snowpack throughout most of the state,” said Scott Pattee, water supply specialist with the National Resources Conservation Office.
The Methow River basin snowpack readings were 128 percent of normal at the beginning of February, one of the highest readings in the state. At the same time last year, the Methow basin snowpack measured 88 percent of normal.
Snowpack is a critical source of water throughout the West, storing large amounts of water that is released as mountain snow melts in spring and summer. Snowpack is measured in snow-water equivalent, which reflects the amount of water contained in the snowpack.
“Basins across northern Washington favor higher snowpack conditions than those further south,” Pattee said in a monthly water supply report. The Conconully basin had the largest snowpack with 142 percent of normal.
The lowest snowpack measurements in the state were at Ahtanum Creek basin, south of Yakima, where snowpack was at 69 percent of the 30-year median for Feb. 1.
The La Niña weather pattern has held strong, bringing mostly warmer and wetter conditions over the northern part of the Pacific Northwest, Pattee said. “Though it seems like it’s been extremely warm and wet, snow water continues to accumulate whether it be snow or rain on snow, it’s all water that can be saved for later use.”
Healthy at Harts Pass
Weather forecasts through mid-February predicted below-normal precipitation and near-normal temperatures, “which does not bode well for heavy snow accumulation,” Pattee said. However, the National Weather Service’s three-month forecast for Washington indicates below-normal temperatures and above-normal precipitation, “which is our best shot at finishing the season with normal mountain snowpack,” he said.
The mountains around the Methow Valley hold a healthy snowpack, with the Hart’s Pass SNOTEL (snow telemetry) station reading 129 percent of normal at the beginning of this week.
Statewide SNOTEL readings were 100 percent of normal on Feb. 1, 8 percent higher than the same time last year, Pattee said. Snowpack on the east slopes of the Cascade Mountains included Yakima area with 95 percent of normal and the Wenatchee area with 105 percent of normal.
Summer runoff for the Methow River is forecast to be 121 percent of average, according to the water supply report. January precipitation in the Upper Columbia Basin, which includes the Methow Valley, was 135 percent of average. Precipitation for the water year, which runs from Oct. 1-Sept. 30, was 114 percent of average for the Upper Columbia. January streamflow for the Methow River was 131 percent of average.
Precipitation in the water year that began Oct. 1 has been below normal in much of the West except for northern Washington, Idaho, Montana, Wyoming and interior Alaska, where precipitation has ranged from near normal to well above normal.
“Snowpack shows an extreme contrast between these wet northern areas … and the very low snowpack in the southerly areas,” the U.S. Department of Agriculture said in a February western snowpack and water supply report.
Many sites in California, Oregon, southern Idaho, Utah, Colorado and New Mexico register record low snowpack, and forecasts of streamflow predict flows well below normal in most of the West.