Hmmmm... Santa Cruz, CA? I'd forget about a hard-shell jacket and stick to a light weight soft-shell for a top coat. Maybe even just a soft-shell vest. On all but the coldest of days, I'd stick to fleece or merino wool. On the coldest/wettest of days, throw on the soft-shell over top. You'll stay warm even if you're wet, and they should be dry by the time you leave.

If it was only 55 to 60 degrees on the coldest of days, and assuming a torrential down poor, I'd still wouldn't wear a hard shell. Personally, I'd wear a quick dry long sleeve shirt and perhaps a short sleeve quick dry shirt over top. I probably wouldn't even throw a vest on. And, I probably wouldn't wear anything over my legs (shorts only) with my regular shoes and wool socks.

I'm used to riding in the rain, I live in the Pacific Northwest.

If you wear a hard shell, you're going to be wet from the underside, as none breathe enough to evaporate all sweat during vigorous exercise.