By Les Zaitz
Federal fire officials are predicting an above-normal risk for significant wildfires in southeast Oregon through August.
That forecast, issued last week, took on added urgency Monday as Malheur County braced for days of thunderstorms across dry rangelands ripe for lightning strikes.
The threat could be compounded by this weekend, when a weather front bringing strong winds may swing through the region. Winds can cause explosive growth of any range fires triggered by lightning or humans.
Each month, the National Interagency Fire Center issues its monthly wildfire outlook for the country. Its Aug. 1 report said there is higher than usual chance of major wildfires in August or September.
“Areas with the great potential for significant large fire activity will be the grasslands and rangelands of the Pacific Northwest east of the Cascades,” the report said.
The report noted rainfall has been below normal and temperatures have been above average this summer and likely will continue to be so through September.
Brett Lutz, National Weather Service meteorologist in Portland, said temperatures had been running 5 to 10 degrees above normal but more recently have been 10 to 20 degrees above normal.
The national report said fuel moisture has been dropping, and last spring’s conditions created a lot of fuel.
Firefighters “report that heavy fuel loading from the wet spring is a significant contributor to fire intensity.”
Lutz explained that forecasters closely watch the “energy release component” of fuels to assess fire risk. That measures how much energy fuels such as grasses and shrubs would release during a wildfire.
“As we moved into the second day of August, those have been at record levels,” Lutz said.
Mike Powell, a fire management analyst with the Northwest Coordination Center in Portland, said the moisture in living plants is closely monitored. He said if shrubs such as sagebrush drop below 100 percent, they become a heat source rather than absorbing heat from a wildfire.
“We’re getting readings as low as 70 percent,” Powell said. “They’re contributing significantly to the intensity of the fires.”
Powell said the “biggest issue” in southeast Oregon is the grass is two to three times normal volume and that provides more fuel for fires.
“Fires burn hotter, they burn more consistently” with such a grass load, Powell said.
He said range fires this summer have required a more aggressive response from fire crews, including a much heavier reliance than normal on aircraft.
Lutz said the vegetation factors are why “we have concerns heading out into the future.”
He said thunderstorms with lightning are predicted for the basin country perhaps into Sunday. By the weekend, a weather front with winds is expected to arrive. That will help detection of wildfires, Lutz said, but it will also make for rapid spread.
They urged ranchers to be alert for the storms and report as quick as possible any suspected fires. Powell said that range fires so far have come in conditions with moderate winds. That could change this weekend.
“If we get a high wind period, there could be very large fires coming out of this,” he said. For ranchers, “the potential loss of your rangeland is fairly high.”