Apply now.

You don't want to be across from an interviewer some day and have them ask: "why did you wait to apply?"

I know of one interviewer at UPS who asked someone why they waited to upgrade. I realize that's a little different question, however, these interviewers tend to love where they work and they want to hire captains, so get in the left seat ASAP (which you already are--good), and get out ASAP--apply.

JMO