Most of the Cali schools are a shot in the dark,but I wouldn't say being OOS really adds much to that. In addition to USC and Stanford, UCLA and I think UCSF have no in state preference. I managed to get interviews at USC and UCLA as an OOSer and my stats are definately not amazing nor did I attend an Ivy league-esque undergrad.
Nonetheless, there are many applicants that do find better luck at hopkins, harvard, etc. than in California and I think it really has to do with the fact that there are a lot of applicants that actually DO want to go to a Cali school over an ivy-league one (probably due to residency preferences, weather, big cities, etc.)
I cant speak for UCSF or Stanford, but if you look at the average matriculant stats for USC and UCLA (which are both very top notch schools), they are actually much lower than for many of the prestigious East Coast schools despite the fact that many students have better luck getting in to the latter. I would say that California schools put significantly more emphasis on ECs and application essays than most other schools so if you really have that going for you then its totally worth a shot.
From personal observations, I'd say if you have a lot of experience working with the Spanish speaking community, especially in a healthcare setting, that would really benefit you the most in Cali school admissions, and would probably make you stand out more than 3.9/40+ applicants without that background.
