I’m digging this offering from All-City. The Low Profile Pack ($89USD) is a 1100cu backpack that’s slimmer and lighter than their previous offering, Captain Phil. They say it should be easier to see over than the Captain as well.
No interior dry bag, but it’s constructed from waterproof materials. All-City says that they’ve “ridden with it in several downpours and there will be a little seepage at the seams on the bottom of the bag, but it’s never been a big deal.” So, essentially, it’s a nearly waterproof regular backpack.