synchronal -
occurring or existing at the same time or having the same period or phase; "recovery was synchronous with therapy"- Jour.A.M.A.; "a synchronous set of clocks"; "the synchronous action of a bird's wings in flight"; "synchronous oscillations"
contemporaneous,
contemporary occurring in the same period of time; "a rise in interest rates is often contemporaneous with an increase in inflation"; "the composer Salieri was contemporary with Mozart"
parallel being everywhere equidistant and not intersecting; "parallel lines never converge"; "concentric circles are parallel"; "dancers in two parallel rows"
synchronic concerned with phenomena (especially language) at a particular period without considering historical antecedents; "synchronic linguistics"
