Dallas ( CNN ) -- Hot , dry weather returns to Texas this week , whisking away the limited relief scattered thunderstorms brought to firefighters in parts of the Lone Star state over the weekend . In a trifecta of potentially bad news for fire crews , the Texas Forest Service said a low-pressure system will push temperatures into the 90s , humidity to 10 % or less and winds up to 45 mph on Monday and Tuesday . The conditions have prompted the National Weather Service to issue a red flag warning for a large portion of west Texas , urging residents to avoid the use of open flames and to avoid activities that may generate sparks . Because of the hot temperatures , bone-dry conditions and high winds , `` accidental ignitions will have the potential to grow quickly into dangerous wind-driven wildfires , '' the weather service said . The system will bring with it a chance of precipitation . However , rain accompanied by thunderstorms can be a mixed-blessing for firefighters , since lightning can ignite new fires . One such fire scorched nearly every inch of a 10,000-acre north Texas ranch , about 70 miles west of Fort Worth . The Cormack family has raised cattle near Strawn for a quarter century , but now are coping with the loss of 15 % of its herd and nearly all of its grazing land . `` Its something you ca n't really explain . This is home , '' Justin Comack told CNN 's Patrick Oppmann . `` I know a lot of people think ... it 's just land , but you know this is my backyard and we ran cattle out here since I was a baby . '' Some of the cattle were nearly incinerated by the fast-moving flames . All Cormack can do is number the carcasses with green spray paint , take their pictures and log their GPS locations , hoping the family eventually will be compensated for its losses . Even for the surviving cattle , the road will be tough -- many suffered burns and may have to be put down . Grazing land has become a precious comodity , with most of the landscape charred following the fire . `` We 've been really lucky that we have friends all over and people , strangers that come together and donate as much hay as they can , '' according to brother Jake Cormack , who said he 's looking for grass leases to feed his herd until `` we can get over this hump . '' The Forest Service responded to 17 new fires over the weekend , but the blazes were slowed by storms that brought softball-sized hail and reports of tornadoes . The largest of these new fires is the Pipeline fire in Tyler and Hardin counties . Covering some 7,101 acres , it was caused by an oil well flare . National Park Service personnel were involved in the fight against the blaze and it is now 90 % contained . Wet weather over the past few days helped firefighters maintain control over many of the fires burning in the state , the Texas Forest Service said . The largest of them is the 207,660-acre Rockhouse fire in Jeff Davis County , which is 75 % contained as of Sunday night . Firefighters had to abandon the fight against the conflagration in the Davis mountains , according to an update from the Forest Service , because of concerns about safety and a lack of reliable communications . The agency said the difficult terrain made use of bulldozers impossible and aerial resources had proved ineffective . The PK Complex of fires burning west of Fort Worth is now 50 % contained , assisted by significant rainfall , the Forest Service said . On Sunday , crews worked on constructing lines through the 126,734-acre fire . The also burned pockets of vegetation around the fire 's perimeter . The 159,308-acre Wildcat fire in Coke County , north of San Angelo , is 75 % contained . On Sunday , crews were able to focus on patrol and mop-up operations , according to the Texas Forest Service . West Texas averages nearly 15 inches of rain a year , according to David Hennig , a meteorologist in Midland . Over the past six months , just 13-hundredths of an inch of rain have been recorded in that part of the state . While October through March is typically the dry season , that amount of rainfall is far below what it should be , Hennig said . Two firefighters have died since the latest outbreaks began , with numerous others injured , state officials said .
NEW : Fires scorch 10,000-acre ranch north of Fort Worth . Police are still working to contain the largest fires in the state . Critical fire activity is forecast for Texas during the first week of the week . The Texas Forest Service responded to two new fires Saturday .