Synoptic composites of the extratropical transition lifecycle of North Atlantic TCs as defined within cyclone phase space

The evolution of 15 extratropically transitioning cyclones in the North Atlantic was studied. The study was carried out through a composite mean of the cyclone phase space (CPS) evolution and composites of the synoptic patterns at various key milestones throughout the extratropical transition (ET) trajectory. Storms are partitioned into post-transition intensifier and weakeners and comparison of their synoptic evolution distinguishes key factors affecting post-transition evolution. It was observed that complex structural differences in the transitioning cyclone (TC) and its environment exist between event where cyclones weaken, remain natural or intensify after transition.