Oregon's healthy snowpack should keep much of the ground wet this spring, and that could help ease late summer's tough fire season, even if just a little, officials say.
Thousands of acres burned across the state costing hundreds of millions of dollars to extinguish last year, and officials say the effects of a persistent drought exacerbated the past three fire seasons. While a healthy snowpack won't have a huge effect on much of the dry lands across the state, it could help shorten this year's fire season in higher elevations and keep lands saturated longer.
More wildfires were sparked from lightning strikes last year than those ignited by manmade causes, and the state's dry soils last summer didn't help. This year however, statewide snowpack levels are a combined 121 percent of 30-year averages as of Feb. 5, which means forecasters are predicting fuller reservoirs and stronger streams for a lengthier period of time in the summer.
Depending on the area, the snowpack mostly starts to melt in April or May, said Julie Koeberle, a hydrologist with the U.S. Department of Agriculture's Natural Resources Conservation Service.
"Once the soils are dry, it then becomes an issue if there are dry lightning strikes, which is what began the fire season in August of last year," Koeberle said. "So in a nutshell, the earlier the mountains are snow-free, the earlier the mountains become vulnerable unless it rains and stays cool in the summer and/or until there are summer thunderstorms."
So far, the conservation service predicts the Willamette, Hood, Sandy and Lower Deschutes basins could have normal to above-normal streamflows, according to a Feb. 1 report from the conservation service.
Forecasters say, for example, there's a 50 percent chance the Willamette River's streamflow levels at Salem could be at 112 percent of the 30-year average from April through September. That's if current weather conditions remain the same through the spring.
Meanwhile, the Silvies River near Burns in southeast Oregon Harney Basin could have almost twice the stream flow as the 30-year average.
"If we have a good snowpack coming into the fire season, it tends to shorten the length (of the fire season) on the front end," said Rod Nichols of the Oregon Department of Forestry. If snowpack levels remain, "we probably won't see as many active large fires early in the fire season at high altitudes."
The National Weather Service's Climate Prediction Center has also called for above normal temperatures in February, March and April in the state. In northern areas, the center has called for below average precipitation during the same time period.
That could mean snowpack levels could suffer, but a good snowstorm could help keep levels at normal, Keoberle said.
Despite this winter's precipitation, the U.S. Drought Monitor this month said southeast areas of the state remain with moderate to severe drought conditions.
Last year, Oregonian saw 2,588 fires that spanned 685,809 acres on state and federally protected lands, according to the Northwest Interagency Coordination Center, which allocates firefighting resources for Oregon and Washington. The fires cost $240.5 million, according to the Oregon Department of Forestry.
Last year's fires surpassed 10-year avareges. According to the center, an average 2,517 fires erupted burning an average 442,963 from 2005 to 2014.
Nichols said it's too early to get a full prediction about the severity of this year's fire season. Last year's seasons started in June and ran through October.
But, "As the old fire dogs say, 'We always have a fire season. We always have a summer,'" Nichols said. "Meaning that undoubtedly we will have hot dry weather this summer across much of Oregon. So we'll have fire conditions out there conducive to having wildfires."
-- Tony Hernandez
thernandez@oregonian.com
503-294-5928
@tonyhreports