Washington, Shawwal 20, 1436, August 05, 2015, SPA -- California fire authorities were bracing for potential lightning strikes from scattered thunderstorms forecast for Wednesday and Thursday, with major wildfires already blazing in several parts of the arid western US. The California Department of Forestry and Fire Protection (Cal Fire) were on a high alert and warned of the risk of new lightning-sparked fires in the state's drought-parched northern inland region. The largest single existing blaze was affecting at least three counties north-west of state capital Sacramento, Cal Fire said. The so-called Rocky Fire has already scorched 26,000 hectares, destroyed more than 25 homes and other buildings and forced mandatory and voluntary evacuations of 13,000 people, the state said. With 3,200 firefighters deployed against it, the blaze was described as 12 per cent contained Tuesday, after crossing a state highway on Monday where Cal Fire had hoped to halt the conflagration. "It's those erratic winds that are making it difficult," a Cal Fire spokesman said. "When you get a fire this big ... it's starting to get so hot and so intense that in many cases it's creating its own weather pattern. It's creating its own winds." White House spokesman Josh Earnest said that nationwide 27 large, uncontained fires were being fought nationwide, with 14,000 state and federal personnel mobilized, plus 108 helicopters and 22 air tankers dropping water and fire retardant. --SPA 03:28 LOCAL TIME 00:28 GMT www.spa.gov.sa/w