The good news (so far) is that snowpack in the mid-valley is holding its own as we finally make the turn from winter to spring. 

But that news, welcome as it is, comes with a pair of big asterisks:  

First, even above-average snowpack levels can melt away in a hurry, given warm weather conditions. What you want to see is snowpack lingering well into spring to help keep stream flows steady and strong well into summer. 

But all the indications so far this year are solid: As of Sunday, the Willamette drainage was sitting at 128 percent of average. The statewide numbers are even better: Across all Oregon drainages, snowpack was sitting at 138 percent of normal.

In part, this is a big deal because it's the first time in nearly a decade that statewide snowpack has been well above normal on March 1. (In 2008, the statewide snowpack on March 1 was 157 percent. Last year, by contrast, the snowpack was at 94 percent of normal.)

That wet and chilly February we endured was good news for the state's snowpack: In previous years, warmer than usual Februaries have wreaked havoc with snowpack. 

It all translates into slightly better-than-average stream flows in the region for April through September, according to the March report from the Natural Resources Conservation Service, a branch of the U.S. Department of Agriculture. (President Trump's proposed budget, by the way, seeks an 21 percent cut in the Department of Agriculture, but enough about that for now.)

In the words of the March stream flow forecast: "Water supplies in the basin are likely to be near normal to well above normal this summer."

And that's good news for people who depend on water, a list that includes just about all of us. It's particularly good news for farmers and for people who enjoy fishing and boating and rafting and other outdoor recreation. It's also a good sign for those of us who worry about the summer wildfire season, which seems to already be in full swing in other spots around the nation.

Now, the second asterisk: The low snowpack levels the region experienced in 2014 and 2015 might become increasingly common, according to a recent study from Oregon State University researchers. 

The researchers, including Eric Sproles, who conducted much of the work as a doctoral student at OSU and has been working as a hydrologist in Chile, noted that both those years had adequate precipitation. The problem was that most of the moisture fell as rain instead of snow.

The study, which was supported by the National Aeronautics and Space Administration and the National Science Foundation, was recently published in the journal The Cryosphere.

Sproles and his fellow researchers focused on what happened in the Cascade Mountains at an elevation of around 4,000 feet, a level that frequently marks the boundary between rain and snow. In 2014, they found, winter precipitation was 96 percent of normal. But temperatures in the snow zone were 2.7 degrees Celsius warmer than average.

2015 was drier and even warmer, the researchers said, with 78 percent of normal precipitation and temperatures that were 3.3 degrees Celsius warmer than the average. The result: On March 1, 2015, nearly half of the snow-monitoring sites in the Willamette River basin registered zero “snow water equivalent” — the amount of water stored in snowpack.

In other words, the researchers warn, if temperatures continue to stay above average, the ample snowpack we have on hand this year might be increasingly uncommon, with real long-range repercussions for the mid-valley. And that's a big shadow over what should be a sunny situation. (mm) 


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