I would say very competitive. California healthcare programs are severely impacted right now, there is a very high applicant/program ratio and lots of budget cuts. P.A. school in general can be as hard (or harder) to get into than medical school, so all programs are pretty competitive. California programs accept about 5% of applicants.
A competitive GPA for both Western and UCDavis is considered to be above 3.5, even though the minimum requirements may be lower.
UCDavis (I'm not sure about Western) also requires two years PAID, full time healthcare experience; they favor nurses, EMTs, and Medical Assistants. Their program doesn't really favor recent college grads, they're more geared toward healthcare professionals looking to further their patient care careers. Many P.A. programs are like this, (although not all) so it's important to check on that before applying. Volunteer experience is a great addition, but for some does not fulfill the entire patient care requirement.
I had a 4.0 GPA, 8,000 hours paid and 2,000 hours volunteer patient care exp., and didn't get in anywhere in CA; I ended up getting in to numerous schools in other parts of the country, however.
Another thing you'll need to be a competitive applicant is at least 100 hours shadowing a P.A. Even if a school doesn't require it, they generally feel that you're not a terribly competitive applicant without it, particularly CA programs.
I actually called all the programs I was interested in and reviewed my background with the admissions counselor, then asked what else I would need to do to make myself the most competitive applicant possible. Each program had a slightly different answer, and by doing this I was able to rule out programs I wouldn't be eligible for, as well as find some that were a perfect fit admissions-wise. I strongly recommend doing this!
Hope I wasn't too discouraging, PA school is awesome, I wish you the best of luck! :)