A wind-driven California wildfire that erupted east of San Francisco appeared to be spreading on Sunday, forcing evacuations and highway closures. About 400 firefighters were battling the blaze, which covered about 12,500 acres in San Joaquin and was only 15% contained, according to the California Department of Forestry and Fire Protection, known as Cal Fire. “Strong winds and dry grass have made it difficult for firefighters to contain,” the Cal Fire Santa Clara Unit said Sunday morning on Facebook. Dramatic aerial photos posted Sunday on the Santa Clara Unit’s Facebook page showed the Corral…