BOISE, Idaho — February has brought most of the Pacific Northwest badly needed wet storms and an outlook for more moisture, but weather experts warn irrigators still face a huge deficit due to extreme dryness through January.
Basins across central and southern Idaho received 75-95 percent of their full February precipitation during the first 11 days of the month, said Ron Abramovich, Idaho water supply specialist with the NRCS.
“We’ve got about 18 days to go, and there’s wet weather moving in. We’re off to a great start,” Abramovich said, emphasizing it will still take a series of storms to get Idaho back on track.
Gary Wicklund, an Idaho meteorologist with the National Weather Service, said Pacific Ocean conditions have shifted toward a wet pattern known as a Pineapple Express. Systems south of the Aleutian Islands have grown strong enough to push warmer and wetter systems from as far west as Hawaii into the Pacific Northwest, nudging a high-pressure ridge pervasive throughout January southwest.
Wicklund said such conditions should persist through at least Feb. 19, bringing slightly warmer temperatures and decent storms into the region every couple of days.
Oregon NRCS hydrologist Julie Koeberle said three storm systems have hit her state’s northern basins from early January through now. Southern basins in the Klamath and Siskiyou mountains and the Southern Cascades, however, have been mostly missed.
Koeberle remains hopeful that the Pineapple Express may still reach southern Oregon, where snowpack is about a third of normal, reservoir storage is meager and irrigators have already requested state disaster declarations. She said several snowpack monitoring sites in southern Oregon are at or below the record-low levels of 1977.
“It’s a dire situation to be honest in those areas,” Koeberle said.
Even in Northern Oregon, she said, precipitation at most snow survey sites only ranges from 60-75 percent of normal.
Washington has fared no better, NRCS water supply specialist Scott Pattee said in a press release.
“We would need to see 200 percent of normal snowfall over the next two months to catch up to normal,” Pattee said. “Today’s best advice would be conservation and conservative planning for summer water use.”
Through Feb. 1, Pattee said Washington had received just 35 percent of its annual snowfall, half the amount of a normal year. Readings in the Olympic Peninsula were the state’s lowest, at a quarter of normal.
Idaho ended January with about a third of its snow telemetry stations reporting record-low precipitation for the water year and the NRCS warning of likely shortages in the Owyhee, Salmon Falls and Oakley basins. Idaho basins along the continental divide, including the Upper Snake Basin, reported near average snowpack but dismal storage water carryover.
Steve Howser, general manager of Aberdeen-Springfield Canal Co., which utilizes Upper Snake storage, said his water outlook has changed dramatically during the past two weeks. At lower elevations, he’s optimistic melting snow will replenish soil moisture, and he’s now anticipating a normal season for utilizing the Snake River’s natural flows. Idaho water officials are scheduled to meet Feb. 14 in Boise to update their extended irrigation outlook.
“If this Pineapple Express keeps coming for the next few weeks, we’ll probably not have any more difficulty than we had last year,” Howser said.