Finally bought a new spring coat! It’s from Roots, and is called the Newport Mac rain jacket.
I was looking for a not-plain raincoat/windbreaker, and was very pleased when I found this. It also comes in a bright yellow!
I bought a size large, and it fits a pretty big on me, but the sleeves of the medium size were way too tight (definitely too tight to ever wear a sweater under it) and also a bit snug in the underarm, so I am compromising there.