Southern California received much-needed rain Thursday as residents prepared for a second, more powerful storm that could bring much heavier rain and prompted fears of mudslides in some communities. The weather system had moved south from northern California, bringing up to 2.5 centimeters of rain in drought-stricken coastal and valley areas of the Los Angeles region, and more in the mountains. Earlier, about the same amount of rain had fallen in the San Francisco Bay area, causing the cancellation of about 100 commercial flights. The storm, and the far larger one expected to arrive Friday, brought worries and recommended evacuations in some areas northeast of Los Angeles because they sit at the foot of the steep San Gabriel Mountains, where a wildfire last month stripped trees from 2,000 acres where rushing water now could pose a danger. Sandbags were being provided in more communities along mountain ranges east and west of Los Angeles, where other wildfires have burned in recent years. The National Weather Service (NWS) said the second storm will move across southern California from late Thursday through late Saturday, reaching Los Angeles early Friday morning, with rainfall amounts ranging from 7.5 to 15 centimeters in the foothills, and up to 20 centimeters in localized areas. Despite the risks posed by the storm, California badly needs precipitation, with 2013 ending as the western state's driest year on record.