MOUNT VERNON, Wash. — Warm weather worries about Washington’s mountain snowpack in early February were buried by ample snowfall in the second half of the month.
Statewide snowpack was 109 percent of normal on March 2 compared to 100 percent of normal on Feb. 5, according to Scott Pattee, state water supply specialist for the USDA Natural Resources Conservation Service in Mount Vernon.
“La Nina years typically start out not that great in snowfall, warm and wet, and ‘winter’ comes at the end of winter,” Pattee said.
Cooler weather since mid-February brought mountain snow and more is likely to make a higher percent of normal snowpack on April 1 than on Jan. 1, he said.
“Cooler than normal temperatures is the key. We’re getting into the season where snow will be more in the mountains than the valleys. Soil moisture is good everywhere at 100 percent of capacity,” he said.
It all bodes well for summer irrigation of farmland in the Yakima Valley and around the state.
A 12-day warm streak started in late January and ran through Feb. 8 with most midnight temperatures above freezing at 3,950-foot Stevens Pass. The mountains were not getting a lot of snow.
But a Feb. 16-20 storm brought 6 inches of accumulated (settled) snow to the agency’s Stevens Pass SNOTEL (snow telemetry) site and a Feb. 23-26 storm brought 22 inches, Pattee said.
Parts of the North Cascades received more than 24 inches of accumulated snow and Fish Lake above Cle Elum received 34 inches, helping feed the farm-rich Yakima Basin.
Five mountain reservoirs, providing irrigation water to 464,000 acres of Yakima Basin farmland, were at 74 percent of their 1,065,400-acre-feet capacity and 135 percent of their average on March 2. Precipitation at the reservoirs, Oct. 1 through March 2, was 186 inches, or 115 percent of average, according to the U.S. Bureau of Reclamation.
Oct. 1 to March 2 SNOTEL snow depth accumulation totals were 110 inches at Stevens Pass, 92 inches at Fish Lake above Cle Elum, 151 inches at Lyman Lake above Lake Chelan and 153 inches at Brown Top ridge west of Ross Lake, Pattee said.
“Those are all pretty normal readings, nothing extreme,” he said.
Snow water equivalent snowpack in the Spokane Basin was 114 percent of normal on March 2. The upper Columbia (Okanogan and Methow rivers) was 136 percent. The central Columbia (Chelan, Entiat and Wenatchee) was 105 percent, the upper Yakima was 99 percent and the lower Yakima 101 percent. Walla Walla was 85 percent, the lower Snake River was 113 percent, the lower Columbia was 101 percent, south Puget Sound (from Cascade crest to lowlands) was 96 percent, central Puget Sound 106 percent, north Puget Sound 122 percent and the Olympics 124 percent.