Banning I was looking around for info on the test and found this:
National Weather Service - On Line Testing Page
For you to take an on-line exam, you must currently be an employee of the U.S. Department of Transportation, Federal Aviation Administration (FAA), or a private contractor working for the FAA. You must also be working in a job requiring a valid Pilot Weather Briefing Certificate or a Certificate to take Tower Visibility Observations.
If you are seeking employment with the FAA or an FAA contractor, you CANNOT take these certification examinations to pre-qualify for a job.