While Southwest Oregon is still dealing with the lightning-caused fires that started a week ago, forecasters expect another round of lightning starting Sunday afternoon. The locations affected will be Southwest Oregon and Northern California, including National Forests in the area: Siskiyou, Rogue River, Shasta-Trinity, Fremont-Winema, and Klamath.
The best chance for lightning is Sunday, but it could linger through Tuesday.
Adding to the lightning threat is low relative humidity which is expected to reach into the teens in most locations Sunday.
And piling on to the wildfire danger is the current condition of the fuels. Oregon and Washington are at or over the historic high Energy Release Component (ERC). The ERC is a number related to the available energy (BTU) per unit area (square foot) within the flaming front at the head of a fire. A high ERC indicates more resistance to control — fires are harder to suppress.
With large numbers of firefighting resources already tied up on fires in Oregon, Utah, and California another flurry of rapidly spreading fires could severely test the mobilization capacity of the wildland firefighting agencies. Today over 14,000 personnel are committed to fires, including 362 hand crews, 926 engines, and 126 helicopters.
Before the 2018 fire season started the U.S. Forest Service reduced the number of large air tankers on exclusive use contracts by one-third, leaving only 14 to be shared across the United States. Other air tankers on Call When Needed contracts can supplement the fleet, if they are available, but their daily availability costs average 54 percent higher than those on season-long exclusive use contracts. Their hourly costs average 18 percent higher.
In 2017 the Type 1 helicopters on exclusive use contracts were cut from 34 to 28, and that continues in 2018.