If you're young and single, go for it. You'll need a place to stay in Seattle while you find your own place and get the job situation under control. You'll also need enough money to get by on for at least a month or two.
I had a friend that moved to Colorado like that. He stayed with a cousin while he job searched, and he contributed what he could to household needs. He was able to find a job in a reasonable amount of time, so I'd consider him a success story.
I'm sure there are more failure stories out there than success stories, so get everything you possibly can in order before running off to Seattle. Money, housing, and job research will be things you might want to have ready.