By Karen Brooks
AUSTIN, Texas (Reuters) - The unexpected flare-up of a wildfire in east Texas on Tuesday triggered more evacuations in an area northwest of Houston where some 1,800 people already have been displaced.
The blaze has charred roughly 5,800 acres and devoured 35 homes since erupting on Sunday, through improved weather conditions helped firefighters carve containment lines around a quarter of its perimeter before high winds kicked up again on Tuesday afternoon.
Grimes County Sheriff Donald Sowell told Reuters that fire managers had hoped to take advantage of calmer winds and lower temperatures, "but it didn't work out that way."
"They had more problems with the wind stirring up hot spots," he said. "So it's getting concerning again."
The so-called Dyer Mill Fire, burning through rolling woodlands about 80 miles northwest of Houston, had forced an estimated 1,800 people from their homes by Tuesday. The abrupt spike in winds -- gusting to 25 miles per hour -- prompted authorities to order more evacuations, Sowell said.
The blaze is one of 24 large-scale wildfires -- defined as at least 100 acres in timber or 300 acres in grasslands -- currently burning out of control throughout Texas, according to the National Interagency Fire Center in Boise, Idaho.
While the Dyer Mill Fire poses the greatest current threat to populated areas, the largest fire in Texas was churning halfway across the state, to the west, outside of Abilene, where 40,000 acres have burned so far. Most evacuees from that blaze were being allowed back home Tuesday evening.
Drought-parched Texas accounts for the bulk of 52 major active wildfires nationwide, most of them in the South and Southwest, in what has so far shaped up as an especially tough fire season.
Those blazes have scorched nearly 1.4 million acres in all, while the combined acreage for all 34,300 wildfires tallied across the country so far in 2011 tops 7,000 square miles -- an area larger than the state of Connecticut.
Year to date, the Interagency Fire Center has counted about 7,000 more fires this year than last, with about 3 million more acres burned, spokeswoman Tina Boehle said. But despite considerable property losses, human casualties have been few.
Two forest rangers were killed on Monday while battling a blaze in northern Florida, becoming the state's first firefighters to perish in a wildfire in 26 years.
In eastern Arizona, diminished winds were helping firefighters turn the tide against the biggest wildfire ever in that state -- and the nation's largest active blaze -- the Wallow Fire in the Apache-Sitgreaves National Forest.
That blaze has consumed nearly 528,000 acres, or 825 square miles, of mostly ponderosa pine forest in Arizona's White Mountains area near the New Mexico border since May 29. Investigators believe it started with an unattended campfire.
The fire forced some 10,000 people from their homes at its peak. By Tuesday, all but about 200 people from the town of Luna, New Mexico, just east of the Arizona border, had been permitted to return, and fire crews had extended containment lines around nearly 60 percent of the blaze.
About 200 miles to the south along the U.S.-Mexico border, the Monument Fire has gutted at least 62 homes and displaced an estimated 11,000 people near the town of Sierra Vista, Arizona. About 27,000 acres have burned in all since the blaze began a week ago.
Firefighters there also got a boost from lighter winds, and by Tuesday had managed to carve containment lines around 40 percent of the blaze. But much of the Monument Fire continued to burn in remote terrain inaccessible to ground crews. The area also was reopened to about 300 more evacuees, leaving only a few hundred still displaced.
Cochise County, Arizona, Sheriff Larry Dever said on Tuesday that both the Monument Fire and a separate blaze that has charred 223,000 acres of southeastern Arizona near the border were likely caused by Mexican smugglers.
Federal fire officials, however, say the cause of both those fires remains under investigation.
(Additional reporting by Tim Gaynor; Writing by Steve Gorman; Editing by Greg McCune)