MANHATTAN BEACH, Calif. (KABC) -- A rainy week is in store as Southern Californians return to work after the long holiday break.The storms were expected to hit Monday morning, and the strongest of the storms will come Tuesday. In light of the strong storms, high surf advisories were in effect until Thursday night.Los Angeles County Lifeguards warn that the rip currents will be dangerous and strong during the stormy week. Waves were estimated to be as high as 7 feet Monday, but could grow to 15 feet by Thursday."We're expecting large rip currents and hazardous surf," said Spencer Parker with the Los Angeles County Lifeguards. "If you do get caught in that scenario, we want you to remain calm and wait for help. And if you do feel like you can make an attempt to self-rescue, swim parallel to shore to get yourself out of the rip current first and then try to get yourself to shore."Other concerns include beach erosion and damaged piers in cities such as Manhattan Beach, Ventura and Port Hueneme.The El Nino-related system prompted Mayor Eric Garcetti to urge Los Angeles residents to prepare for floods and debris flows During a brief news conference Sunday night, Garcetti said the city has spent months clearing out thousands of storm drains and it will also activate its emergency operation centers to track the storms."This storm is real and it's coming. So this week, there are things that you can do right away, from clearing out your storm drains to making sure if you live in the hillside areas (that) you come to your neighborhood fire station where you can get sandbags," he said.More than 1,500 beds are also available for those who are homeless and who may lose their homes in the storms, Garcetti added.Residents in Calabasas and Ventura County stocked up on sandbags and barricades to alleviate any debris flows that could happen during the heavy downpours.At least four storms are expected to sweep over Southern California, with the largest happening Tuesday . The storms should bring a few inches of rain and feet of snow in the mountain areas. There are also threats of thunderstorms.Residents in burn areas are urged to be careful as many of those spots will be prone to mudslides.For more help, including emergency notifications sent to your phone, residents were encouraged to visit elninola.com