LOS ANGELES (AP) — Much of California simmered in a stew of high heat and humidity on Thursday, bringing thunderstorms, causing power outages and leaving some school kids in overheated classrooms. The sweltering, erratic weather was being generated by a ridge of high pressure over the state and the monsoonal flow of moisture from Tropical Storm Linda, the weakening former hurricane spinning in the Pacific about 400 miles southwest of San Diego. The weeklong heat wave, which has produced triple-digit temperatures up and down the state, was expected to start receding Friday.