CALIFORNIA — Wildfire experts knew the Northern California region where the Park Fire sparked was ready to burn, but no one expected how fast it would go up in flames. In just three days, the fire exploded into the state’s seventh-largest wildfire on record. …As of Sunday morning, it had spread to more than 350,000 acres. Neil Lareau, at the University of Nevada at Reno, said, “This fire is right up there with the fastest growing fires in history.” …A volatile mix of ingredients combined to make this particular blaze one of the most extreme the state has seen. …Much of California is on track to see its warmest July on record. …Cal Fire officials said that this blaze is a “plume-dominated fire.” That means the power of the fire is stronger than the wind, and it produces its own convection columns. …There is a high fuel load and abundant grasses in the region.