A climatology of the extratropical transition of Atlantic tropical cyclones

The temporal and spatial distribution of extratropical transition of Atlantic tropical cyclones are examined. Variations exist on both the seasonal,interannual, and decadal scales. The impact upon middle and high latitudes is explored through return periods of both TCs themselves, and TC-induced heavy rainfall. Explanations for the seasonal variability are discussed, along with a discussion of the post-transition intensity change following transition--a major issue for forecasters attepting to forecast the distribution of wind and rain from these cyclones. The vast majority of post-transition intensifiers form deep in the tropics, with the majority of post-transition decayers forming in the subtropics or middle latitudes. The cause for these differences is discussed in detail. An explanation is also provided for the factors dictating why some storms intensify afer transition, while others decay.