Just to add to what Brian is saying, I've lived in LA close to 11 years and this isn't the first time the media and weather people have warned of a major storm only to have it fizzle out and turn into a sprinkle or two. From what I get there is something in the atmosphere over socal that has to hold together for these storms to hold their punch and 3/4 of the time it doesn't happen and so the storms, "fall apart" as Dallas Raines on KABC would say. It is an El Nino year, so perhaps that means the storm will hold together?