Most of danger lies in the Southwest, much of the Plains and parts of the South, the National Weather Service warned, adding that severe drought and above-normal temperatures across the region are expected to persist.
Florida, Louisiana and Nebraska, as well as parts of California, South Dakota, Illinois, Missouri, Arkansas and Mississippi, also show above-average wildfire potential. So does Alaska.
Meanwhile, the strong winds that pushed wildfires across nearly a million acres of the bone-dry Texas Panhandle have eased, but in Oklahoma, the fire danger continued Thursday.
A series of wind-whipped grass fires broke out Wednesday in Oklahoma, charring more than 4,000 acres and briefly threatened homes near Oklahoma City.
Most of the state was under a red flag warning Thursday morning, meaning a critical danger of fires because of the dry air pushing into the region and the forecast of 20-25 mph winds, the National Weather Service said.
In Texas, where 50-mph wind gusts had swept a line of flames toward six Panhandle cities on Wednesday, the winds had shifted by Thursday morning and dropped below 10 mph.
"It's a big relief to know I can go home and go to bed tonight and not have to worry about my house catching on fire," Ronnie Ledbetter, a resident of Pampa, Texas, told CBS correspondent Manuel Gallegus.
"Right now, the fire is contained," said Lipscomb County Sheriff's dispatcher Jay Johnson, whose office had urged nearly 3,000 residents in the far northern county to evacuate the day before. "The wind has shifted and they've lit a backfire to get the fire burning back on itself."
Authorities said the fires had traveled as far as 40 miles to the northeast on Wednesday. This was firefighters' worst-case scenario, CBS News correspondent Kelly Cobiella reports.
The winds, which blew away ash and created sandstorms, were the strongest since wildfires started racing across the plains northeast of Amarillo on Sunday. Eleven people have died, more than 840,000 acres have burned, and animal health officials have estimated the number of dead horses and cattle at 10,000.
"The winds, while not as high as they were Sunday and Monday, are still going to be gusting up to 30 or 35 miles an hour in the Panhandle area. We also have low relative humidity, which is one of the factors that will cause everything to burn," Pat Schaub of the Texas Forest Service told CBS Radio News. "We just have to watch and hope that the winds cooperate and the relative humidity cooperates and we do eventually get better conditions to where we'll be able to put the fires out."
"When fire is advancing at 40 mph, you can't put it out," Borger Fire Chief Gayland Darnell said. "It would be like trying to stop a tornado."
Gov. Rick Perry was scheduled to tour the area Thursday.
In Oklahoma, already under a burn ban because of fire outbreaks in recent months, 14 fires raged Wednesday from near Lawton, in the southwest, to west of Tulsa in the northeast, said Dale Armstrong, a fire information officer.
The largest of those fires burned about 3,000 acres near Moore, southeast of Oklahoma City, forcing the evacuation of 30 homes for several hours Wednesday, Armstrong said.
"I'm just praying because that's all you can do when you see flames
coming at you like that," Edna Hatchett a homeowner in Oklahoma City told Gallegus.
Wildfires have also broken out in western Kansas, where 14,000 acres burned Wednesday in Hodgeman County.
"It's dry. It's way too dry," said Joy Moser, spokeswoman for the Kansas Division of Emergency Management. "We haven't had anything like this in years."
In Texas, fires have consumed about 3.7 million acres and nearly 400 homes since late December.
Firefighters in Texas were battling 10 major blazes Wednesday and responded to more than 200 new fires for a second consecutive 24-hour period. The Panhandle got some relief Wednesday afternoon with brief rain in the Borger and Pampa areas, overcast skies and higher humidity.
In their efforts to quell the wildfires, some departments have used soapy water because it sticks to vegetation better and doesn't evaporate as quickly. Firefighters also have set back fires and used bulldozers to clear land in an effort to rob advancing fires of fuel. Helicopters have dropped hundreds of thousands of gallons of fire retardant and water.
In the sparsely populated rural Panhandle, the mostly flat terrain combined with grasses and some brush that can fuel fires contribute to quickly advancing flames.
"The problem," said Frederick, "is they can spread over such a wide area quickly, exponentially, it makes it hard to get a handle on it."