I’d work with the assumption that you’ve got less than 50/50 odds of getting in. More current test scores won’t sway them. (besides, your SAT and ACT are well above avg for the school) Do what they ask, make sure they know you are interested by ‘accepting’ their offer.
http://admissions.ucsc.edu/apply/waitlist-student-faq.html
That’s the official UCSC Wait-list FAQ
Here is some more general waitlist info.
http://■■■■■■■■■■■■/home/uc-freshman-waitlist-information-waitlist-statement-guideline/
Then, as the name implies, you wait - possible until mid-May. While waiting, make other plans - secure a seat and housing at your fall back (I understand CP Pomona is taking deposits now).
Good luck.