A refined Hovmöller diagram

A refinement is proposed to the conventional Hovm¨oller diagram. The rationale is set out for the refined approach, a description provided of its design, and examples presented to illustrate its value as a diagnostic tool. It is shown that it can depict the dynamical characteristics of synoptic-scale disturbances as they evolve on a meandering tropopause-level waveguide, and in particular it can detect wave-breaking events, cut-off formation and vortex re-connection