April has come in like a lamb in Oregon, where forecasts for a abnormally warm and dry spell could mean no new additions to the state's low snowpacks.
Despite a wet and surprisingly snowy March, the Rogue River Basin's snowpack has crept up to just 36 percent of average Thursday and the total precipitation remains just 73 percent of average, according to the Natural Resources Conservation Service.
Southern Oregon has seen a string of eight springs in which unseasonably cooler and wetter weather patterns helped add rainfall to reservoirs and snowpacks to mountains — a wet bailout in several of those years.
But the federal Climate Prediction Center calls for the opposite weather patterns now through June statewide, meaning the snowpack and rainfall levels won't improve this spring as they have in past seasons.
"The safe bet is to say what we got now is what we're going to get," NRCS hydrologist Julie Koeberle said Thursday. "Anything else we get from here on out will be a bonus.
"That doesn't mean we can't see a cool storm moving in over the next three months," she says. "It's just not something we can bank on."
The NRCS is putting the final touches on its April streamflow forecasts and it's the one irrigators and reservoir managers look at closely to predict the summer water season. That report could be out as early as today, Koeberle said.
The first week of April often sees the peak of the Oregon snowpack levels and the start of the so-called "snow-melt phase" of the water season, she said.
Oregon actually saw some melting in mid-March, compacting snow levels statewide. But the last week of March brought enough snow that places such as Big Red Mountain accumulated more snow that week than all of the past season, NRCS data show.
Still, the 6,050-foot peak near Mount Ashland on Thursday sported a snowpack of just 21 percent of average — a record low since the gauge was enacted in 1981, according to NRCS data.
With a total precipitation at 62 percent, Big Red Mountain helps tell the story of winter weather patterns that brought more rain to the Siskiyous and more snow to the cooler Cascades despite their elevations.
For instance, at Annie Springs within Crater Lake National Park, the SNOWTEL site is 40 feet lower than at Big Red Mountain. But it was listed Thursday with 60 inches of snow — 19 inches of it since March 25, SNOWTEL data shows.
"That's sort of the way the storms have gone," Koeberle said.
The official Crater Lake snowpack measurement at park headquarters on Monday, however, was 103 inches of snow, or 63 percent of average.
After severely lagging in their filling schedules before a wet February bailed them out, Lost Creek and Applegate reservoirs were close to being on track for filling by the May 1 annual target.
Lost Creek Lake was listed Thursday at 92 percent full and 2 feet above its filling schedule. Applegate Lake, which had been close to 50 feet lower than normal in January, was listed Thursday at 71 percent full and less than 6 inches shy of its filling schedule. Both U.S. Army Corps of Engineers projects are filled primarily with rainfall.
Hyatt and Howard Prairie reservoirs, however, are primarily snow-fed. Hyatt was listed Thursday at 51 percent full and Howard Prairie was listed at 58 percent full.
Reach reporter Mark Freeman at 541-776-4470, or email at firstname.lastname@example.org.