The latest in a series of powerful storm systems is pelting mountain areas of California with heavy rain, snow and high winds, prompting evacuations and leaving thousands without power. Virtually the entire state has been affected by the storms that began Friday, dumping moisture from far Northern California south to San Diego. More than 12 inches of rain have fallen in parts of the Santa Monica Mountains in the south and 13 feet of snow has accumulated at Mammoth Mountain ski resort. Downtown Los Angeles had received 5 1/4 inches of rain since Friday morning, more than a third of the average annual precipitation, the Associated Press reported.