I don’t know the situation for California but my guess is that you’re right about your suspicion. I’ve been keeping an eye on London case numbers from reported tests and on numbers from the Zoe Covid study. Numbers from the latter started to rise to concerning levels well before positive tests started to rise. And now it’s the entire UK that’s under a surge of Omicron BA.2. I assume the same thing is playing out in other places, and for whatever reasons, be it testing or something else, the positive tests may lag behind other indicators. (The Zoe Covid study is based on regular self-reports on symptoms via an app.)
I don’t know the situation for California but my guess is that you’re right about your suspicion. I’ve been keeping an eye on London case numbers from reported tests and on numbers from the Zoe Covid study. Numbers from the latter started to rise to concerning levels well before positive tests started to rise. And now it’s the entire UK that’s under a surge of Omicron BA.2. I assume the same thing is playing out in other places, and for whatever reasons, be it testing or something else, the positive tests may lag behind other indicators. (The Zoe Covid study is based on regular self-reports on symptoms via an app.)