Our weather guy Bill Westphal refers us to Ken Clarke's Accuweather blog for the western U.S.:

All signs now point to the good possibility of a strong Santa Ana wind event setting into Southern California late Wednesday night and Thursday … This will be set up about as perfect of a high wind situation as one can get. This certainly is shaping up as a once a decade type wind storm if everything falls in place as it is looking right now. The strongest winds are most likely in Ventura, Los Angeles and Orange Counties and across the Inland Empire in all Santa Ana wind prone areas … Winds of 30 to 60 mph with gusts to 70 mph seem most likely in the populated areas but I could see wind gusts up to 90 mph on the top of some of the non-populated mountain tops.

Take in or secure anything in your yard that could become an outdoor missile.  Secure your brand-new Athens rolling trash cans, keep your animals indoors, and make sure your flashlights and emergency radios are in place in case of power outage.  Travel will also be sketchy, so be prepared.