Does bad senior year (high school) matter for junior transfer?

So I was disappointed in the colleges that accepted me and I ended up accepting to UCSB. I want to transfer in one of the top tier colleges like Northwester, Vanderbilt, and maybe an Ivy league. I had pretty good grades throughout high school except freshman and senior year. Freshman year is obvious on bad grades but for senior year, I didn’t think I was going to transfer so I just slipped and let senioritis get the best of me. I’ll probably end up with a 3.9 weighted GPA and 3.7 unweighted.

Assuming I get a really high GPA during first two years of college, how much would my HS grades count in admissions? Thanks.