What is an appropriate length of time before submitting a request to transfer to a different location?

I have been working for Chase as a personal banker for 6 months, I love the company, get along great with my boss, other co-workers, and have been a superb employee. I want to stay with the company; however, family problems have come up needing my attention, and would require me to relocate to another state. There are the same job positions available where I am needed, and I would really like to stay with the company. Is 6 months long enough to request a transfer? If not, how long should I wait to request a transfer? I am posting here before talking to human resources in order to avoid any bad feelings with my boss, or potentially losing my position within the company (if that's even legal).