Firefighters in Texas faced calmer weather conditions while attacking deadly wind-driven wildfires, but worried that approaching thunderstorms could create new problems.

Bill Beebe, a spokesman for the Texas Forest Service, said conditions were "pretty quiet," though firefighters had yet to contain more than 122,000 burning acres, including two new fires in East Texas.

The major concern was that lightning from thunderstorms predicted for Sunday could spark additional fires, he said.

"We're bracing possibly for some difficult times," he said.

Click here for photos.

Ken Schneider, a meteorologist with the National Weather Service in Amarillo, said the threat of thunderstorms Sunday encompasses all of North Texas.

In neighboring Oklahoma, grass fires that have plagued the state in recent days flared up again Saturday in two counties, prompting temporary evacuations.

Midwest City firefighters battled a blaze that threatened two housing subdivisions. Authorities evacuated residents from parts of Midwest City and neighboring Choctaw until the fire was brought under control, said Fire Chief Randy Olsen.

The fire was in an area unaffected by a massive wildfire that started Thursday and resulted in the loss of about 70 homes in Midwest City and Choctaw, said Fire Marshal Jerry Lojka.

In Carter County in southern Oklahoma, a fire threatened the small town of Tatums, and some homes were evacuated.

Meantime, the Federal Emergency Management Agency said Saturday it has authorized the use of federal funds to help fight the fire in Palo Pinto County, west of Dallas. The authorization makes FEMA funding available to pay 75 percent of eligible firefighting costs.

Firefighters haven't been able to contain any of the Palo Pinto fire, Beebe said. The fire has burned 700 acres, destroyed 14 homes and threatened 198 homes, he said.

Firefighters also have had little success containing a fire covering 25,000 acres in Montague County, northwest of Dallas, Beebe said.

The two fires that developed Saturday were in Red River and Camp counties in northeast Texas.

Three people died and more than 100 homes were destroyed by the fires as they raged through western and central Oklahoma and North Texas on Thursday. Officials suspect that at least one of the fires was intentionally set. The blazes eased Friday as wind diminished from the peak of up to 70 mph.

All three deaths were in Montague County. A couple died when fire overtook their home, and another woman died after calling for an ambulance, Sheriff Paul Cunningham said. The woman's cause of death was unclear.

The couple was identified as former television reporter Matt Quinn and his wife, Cathy. Matt Quinn joined WFAA-TV in Dallas in 1980 and retired in the early 1990s. Their son, Chris, was hospitalized with burns in Dallas.

Click here to read more from MyFOXDFW.com.