Running in cold rain....what do you wear?

I live in Oregon, so I have to run in rain in the winter months. Usually 30-40 degrees and wet. Best clothing options for up top? Been wearing a not-so water resistant jacket with a long sleeve cotton (I know, I know) shirt.....if lower than 33 o so I'll do a short sleeve shirt under that.

What's the better option, without over heating? Get a new jacket and synthetic shirt? Vest instead with synthetic shirt? Other?!?

I run 4.2 miles at a time at 8 min pace, plus walk an additional 20 min.