January one of the Coldest and Driest in History of Automated Snowpack Reading
Scott Pattee, Water Supply Specialist
SPOKANE, WA (February 7, 2017) – Washington experienced one of the coldest and driest January’s in the history of automated snowpack reading (SNOTEL), according USDA’s Natural Resources Conservation Service. Temperatures were 20 degrees below normal and total precipitation accumulation was as low as 28 percent of average. Seven SNOTEL sites in Washington State set new record low precipitation accumulation and many more were very close. One SNOTEL site with 30 years of data set a new low snow water content record at only 53 percent of normal and many others were very near to a record.
“It seems to the average eye that there is a large amount of snow on the ground, but the mountains did not keep up the pace, seemingly falling behind on a daily basis.” said NRCS Water Supply Specialist, Scott Pattee.
The most recent short term forecast is for above normal temperatures and above normal precipitation, which does not bode well for mountain snow accumulation. The National Weather Service 3-month is for below normal temperatures and above normal precipitation.
The February 1 statewide SNOTEL readings were 91 percent of normal however recent storms brought that number back up to 102 percent of normal. Entiat River near Wenatchee reported the lowest readings at 69 percent of the 30-year median for February 1 and the Lewis River Basin had the most snow with 125 percent.
Washington State received much below normal precipitation for the month of January, however, year to date averages remain near normal. The cold dry weather of January worked hard to erode the surplus precipitation levels brought to us last fall. The highest percent of average rain fall came from the Olympic and Upper Columbia basins at 73 percent. The lowest was in the Central Puget at only 31 percent. Year to date averages range from 128 percent in the Olympics to 85 percent in the Upper Yakima.
Seasonal reservoir levels in Washington can vary greatly due to specific watershed management practices required in preparation for irrigation season, fisheries management, power generation, municipal demands and flood control. A very wet fall helped buffer many reservoirs to above normal levels for this time of year. February 1 Reservoir storage in the Yakima Basin was 360,000-acre feet, 89 percent of average for the Upper Reaches and 137,000-acre feet or 112 percent of average for Rimrock and Bumping Lakes.
The power generation reservoirs included the following: Coeur d’Alene Lake, 46,000 acre feet, 48 percent of average and 19 percent of capacity; and the Skagit River reservoirs at 48 percent of average and 34 percent of capacity. Recent climate impacts and management procedures may affect these numbers on a daily or weekly basis.
Due to the lack of precipitation in January streamflow forecasts have made significant declines in many basins from last month. April-September forecasts for some Western Washington streams include the Cedar River near Cedar Falls, 86 percent; White River, 93 percent; and Skagit River, 83 percent. Some Eastern Washington streams include the Yakima River near Parker 77 percent, Wenatchee River at Plain 78 percent; and Spokane River near Post Falls 61 percent. Volumetric forecasts are developed using current, historic and average snowpack, precipitation and streamflow data collected and coordinated by organizations cooperating with NRCS. Caution should be used when using early season forecasts for critical water resource management decisions since governing conditions are likely to change for the better or the worse.
Since 1939, NRCS has conducted snow surveys and issued regular water supply forecasts. Since the late 1970s, NRCS has been installing, operating and maintaining an extensive, high-elevation automated system called SNOTEL, designed to collect snowpack and related climatic data in the western U.S. and Alaska.
To view the January Snow Survey and Water Supply Forecast for Washington State, go to www.wa.nrcs.usda.gov and click Snow Survey. To learn more about how NRCS is helping private landowners deal with drought, visit www.wa.nrcs.usda.gov.
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