Apple Fire burning in parts of Riverside and San Bernardino counties has grown to at least 20,516 acres and is 5% contained, the California Interagency Incident Management Team said as per CNN. Several factors together are creating major hurdles for firefighters who are battling the blaze. Terrain is the biggest, said Lisa Cox, the fire information officer for the San Bernardino National Forest to CNN. The fire, fueled by high temperatures and gusty winds, is also creating its own weather system, Cox told CNN. The Apple Fire was first reported on July 31 in the Banning Canyon area and forced more than 7000 people to evacuate. The cause of the blaze remains under investigation. During an update on August 3, officials said there were 2,266 personnel, 29 hand-crews, 9 helicopters, 260 engines and 11 water tenders fighting the fire. NASA's satellites were working overtime as they snapped pictures of the large Apple Fire.