POMEROY, Wash. (AP) -- The roaring School fire in the state's southeast corner had seared as much as 27,000 acres by midday Sunday, flaring north from the Umatilla National Forest onto private lands and forcing evacuation of about 150 homes.
Farmers beyond the flames were plowing up broad swaths of earth through fields of wheat and other crops, trying to create fire breaks and save this year's harvest, said spokesman Marc Hollen at the Northwest Fire Coordination Cetner in Portland, Ore.
The leading edge of the fire was about 10 miles south of this rural community.
The flames were moving fast through tinder-dry country _ the School fire covered just 150 acres Saturday morning. But an earlier Sunday estimate of 15,000 acres was off significantly because an inversion layer is holding down the smoke and making it hard for fire managers to see the fire's perimeter.
''We can't see where the fire is,'' Hollen said. ''There's a very thick smoke layer over the region.''
The smoke also grounded water tankers and helicopters for much of the day, he said.
The tower of smoke sent up by the fire indicates it is making its own weather, said Hollen's colleague at the center, John Townsley. ''At the moment it's zero percent contained, burning vigorously in timber, grass and brush. The fire blew up, exhibiting extremely large convection columns,'' Townsley said.
''The bigger the column, the more extreme the winds'' inside the blaze, he said, noting the smoke was visible in satellite photos of the area.
There were no reports of injuries, but three structures have burned, the men said. It could not be immediately determined whether the structures were houses or sheds.
The fire initially was managed by a state team. On Saturday, a regional team came in and determined quickly that national oversight was needed. The national team was on site Sunday, Hollen said.
It's not known how the fire began. No lightning strikes were reported in the area Friday, when the fire began in tinder-dry conditions.
''We could easily see more of this if people aren't careful,'' Townsley said. More hot dry weather was forecast Sunday, with some dry lightning and wind generated by rainfall that evaporates before it reaches the ground.
There were just 270 people and 11 engines on the fire late Saturday, but resources were beginning to pour in from all jurisdictions _ state, federal and local, Townsley said.
Aid also has been requested from the Federal Emergency Management Agency ''because of the threat to residences and homes,'' he said. The affected homes are apparently scattered, likely in drainages, he added. He said primary and recreational residences were probably affected.
While other fires were burning around the state, ''I think the School fire is the dragon on the block right now,'' Townsley said
The fire is feeding on a variety of fuel types, Townsley said: forest, brush, grass and some crop lands. So far about 75 percent of the fire is on the Umatilla National Forest, but the flames are being driven northeast into private lands.
''It may be getting into agricultural fields, too. That's one of the things that would make it explosive,'' he said, adding, ''It's hilly country ... you don't have any natural fire brakes.''
The fire _ covering an area about 11 miles long and five miles wide, according to Umatilla spokeswoman Joanie Bosworth _ burned into the Tuncannon River Canyon and jumped the waterway as it roared north and east. Three campgrounds _ Boundary, Tuncannon and Alder Thicket _ were evacuated.
Another new blaze, the Burned Bread fire, ''took off yesterday'' in sparsely populated northcentral Washington, about 30 miles south of the U.S.-Canadian border and 17 miles east-southeast of Tonasket, and now covers about 1,500 acres, Townsley said. It was first reported Saturday.
''This is not considered to be as dangerous as the School fire,'' he said.
About 43 firefighters were on that blaze, working with two helicopters and 10 engines.
Here are updates on the state's other major fires:
_The Dirtyface fire near Lake Wenatchee in central Washington _ about 18 miles northwest of Leavenworth _ was reported 50 percent contained at 1,075 acres. About 100 homes had been evacuated and other area residents were advised to be prepared for evacuation as hot, dry weather continued. There were more than 650 firefighters at the scene, working with trucks and helicopters to douse the fire and strengthening fire lines near the Whispering Pines subdivision. Fire crews hoped to have full containment by Wednesday.
_The Lick Creek fire, near Cle Elum, had charred 870 acres and was 10 percent contained. Southwest wind Saturday ''pushed it north and east, which is not the way we wanted it to go,'' Townsley said. Residents of 30 homes on the north fork of the Teanaway Creek were evacuated. About 390 firefighters were on it.
_In the North Cascades National Park, the Shady fire remained at a little more than 100 acres and firefighters were wrapping up their work. More than 85 firefighters and three helicopters were assigned to the fire about 12 miles northwest of Stehekin. The fire was believed to have been caused by a person. No injuries were reported.
