MOUNT VERNON, Wash. — While up to 2 feet or more of snow blanketed most of Washington in February, no records were set and statewide snowpack declined slightly from 91% on Feb. 25 to 87 percent on March 4.
“We definitely will have more snow. The question is how much,” said Scott Pattee, state water supply specialist for the Natural Resources Conservation Service in Mount Vernon.
Pattee said he hopes snowpack builds but that it might not because the weather outlook calls for cold and dry in the short term, a cooler than normal March and then above normal temperatures with equal chances of precipitation for April and May.
The state is at 74 percent of its median peak in snow-water content, so it is “behind the eight-ball,” he said, noting March 30 is the median peak date of snow-water content.
“If we can hold onto what (snowpack) we have, we should be OK in most areas. We want normal temperatures and normal runoff. The rate of runoff is critical,” he said.
A sudden warming could quickly reduce snowpack, especially without more snowfall. Low-elevation snowpack melts first. The longer it holds the better, but higher snowpack feeding storage reservoirs is crucial.
A Feb. 27 snowfall didn’t deliver a lot and recent storms have not produced much more snow at higher elevations, Pattee said. Recent storms have done more for the Oregon Cascades and California Sierras than they have for the Washington Cascades, he said. The slight increase in the lower Snake and lower Columbia reflect better snows in southern reaches of Washington, extending into Oregon and California, Pattee said.
Two SNO-TEL (snow telemetry) sites in the White River and Puyallup basins, near Enum Claw, were at 580 and 385percent of normal snowpack, he said. They are about 3,000 feet elevation but their normal snowpack this time of year is 1 inch and now they are at 5 inches and above.
The Yakima Basin’s five mountain water storage reservoirs were at 85.4percent of average on March 4 compared with 89.4 percent on Feb. 18. The reservoirs provide summer irrigation to 464,000 acres of farmland in the Kittitas and Yakima valleys.