BLOUNTVILLE — Sullivan North High School might be available for possible use as a Kingsport middle school as early as 2019, according to a proposal from Director of Schools Jubal Yennie.South High would be turned into a middle school the same year, while Central High would become a middle school that year and East High would continue, with renovations, until 2028.Those are part of the recommendations from Yennie given to the county school board Thursday.