Winter snowfall that supports summer stream flow is one of Wallowa County’s most critical needs. This year, there’s good news. Our 2019 snow-water equivalent as of February 11 stands at or 100 percent of the 30-year average, according to the Natural Resources Conservation Service (NRCS) measurements. And that’s before the next series of winter storms hit later this week.
“Right now, the Imnaha and Wallowa River watersheds are both 100 to 90 percent of normal. All and all it’s a pretty good picture for snow-pack and snow-water equivalent in your region,” said Scott Oviatt, Snow Survey Supervisory Hydrologist for NRCS in Portland.
SNOTEL (Snowpack telemetry stations that transmit data to NRCS every hour) measurements as of February 8 show 39 inches, or 98 percent of normal, atop Mount Howard, and 51 inches, or 97 percent of normal at Aneroid.
As of NRCS’s newly-released February report, the northeastern Oregon region, including the Grande Ronde, Powder, Burnt, and Imnaha watersheds are at an average of 103 percent of normal. Even better, they have, so far, collected 97 percent of normal precipitation for the water year (Oct. 1 – Sept. 30). Oviatt’s optimistic hope is that Wallowa County’s snowpack will remain normal or better. He noted that warmer conditions, like those we have had at times this winter, produce wetter snow and hence more water in the snow pack, even though the snow may not be as deep.
“This week we’re getting cooler arctic air that’s coming down from Canada,” he said. “For the next seven to 10 days or more we’ll see wetter weather and more Pacific moisture overriding the cold air, which gives us more opportunities for snow.”
“The apparent weakening of the current El Nino may lead to a cooler spring with more storm impact,” he said. “That could keep snow in the mountains later in the year, and ultimately, enhance summer stream flow. “
Summer stream flow in the Grande Ronde River at Troy, as well as the Lostine and Wallowa Rivers, is anticipated to be nearly 100 percent of normal, according to the February 7 NRCS report. The Imnaha flow is predicted to be somewhat lower, at about 89-90 percent.
“Stream flow predictions are based on averages of what similar conditions have produced in the past,” Oviatt said. “The numbers could change with a big early spring warm-up and runoff, or the accumulation of a lot more snow.”
Wallowa County weather watcher Scott Hampton is optimistic that mountain snowpack will continue to increase. “Historically we’ve been getting good snows in the mountains during February and March,” he said. “The incoming system that will bring snow this week is part of that pattern.” Hampton’s website josephoregonweather.com provides forecasts and a wealth of local weather and other data for the Wallowa Valley. He’s happy to see wind-blown spindrifts of snow curling from the high Wallowa Peaks. “Those winds create drifts that pack and seal the snow’s surface,” he said. “That’s another way to keep it from melting or evaporating too fast.”
The rest of Oregon is not as fortunate as Wallowa County. The northern Cascades have a mere 58 percent of the normal snowpack, and only 76 percent of normal water-year moisture. Summer stream flow is expected to be below average in the western half of the state according to the February 7 NRCS report.
“While a few more months of winter means there is still time for snowpack conditions across Oregon to improve, a full snowpack recovery throughout the entire state is unlikely,” Oviatt said.
Based on current conditions and long-range weather forecasts, water supplies may be limited this summer across much of Oregon. The NRCS report cautions that water users should be aware that nearly 75 percent of the state is currently listed in a severe or extreme drought status by the NRCS National Drought Monitor.