Just got tenured and promoted, but need to move for family reasons
If you stay behind and work for a year as an associate professor and go on the job market the next academic year, you'll be in a better situation to search for a new tenure track position than if you leave your current position and move immediately.  It's always better to look for a job from a tenured/tenure track position than as an unemployed academic with no current affiliation.  Furthermore, if you leave at this point it may appear as though you didn't receive tenure in your current position. 

When/if you do go on the job market you can explain in your cover letter that you're moving to the new city because your partner is there in a tenure track position.  

Another avenue to follow up on is seeing if your partner's new institution might be willing to employ you (either now or perhaps in a year from now.)   Many institutions have specific "spousal hiring" policies that might be helpful.