If you plan on keeping it up for a while, some coax-seal might be ideal on the antenna connector since you are in Seattle. It's some nasty stuff to work with, but it'll save you some maintenance.
A local mesh group where I live hosts meet-ups that they occasionally announce on 220/440, so keep your ears open for that in your area.
(I am in Denver, so I am a little out of your range. Or maybe not? High solar activity does strange things... Once, I keyed about 4-5 repeaters on 2M from my house, so anything is possible.)