PORTLAND, Ore. (AP) — The threat of thunderstorms and lightning has prompted officials in Oregon to ask for wildfire crews from outside the Pacific Northwest to prepare for additional blazes. Resources are already hugely devoted to a massive fire in the state that has grown to a third the size of Rhode Island. The 537-square-mile Bootleg Fire is burning 300 miles (483 kilometers) southeast of Portland in and around the Fremont-Winema National Forest. The Bootleg Fire is fueled by extreme weather and keeps growing by miles each day. Officials with the Rogue River-Siskiyou National Forest in southwest Oregon are asking for more outside crews to be ready should there be a surge in fire activity there.