As Hurricane Michael threatens the East Coast, Hurricane Sergio is making Southern California beaches dangerous this week. Sergio is churning off the coast of Mexico, bringing dangerous surf conditions until Friday, according to the National Weather Service. Some minor coastal flooding is expected at south-facing beaches, from Oxnard all the way down to San Diego. Hazardous surf conditions will likely last through at least Thursday night. Estimates of surf heights are 5 to 8 feet with sets to 10 feet during the peak of the event.