Explainer: The Poleward Migration of the Location of Tropical Cyclone Maximum Intensity



Over the past 30 years the typical location of LMI has moved poleward in both hemispheres – at a rate of over 30 miles per decade. According to this study, the amount of poleward migration varies by region. The greatest migration is found in the northern and southern Pacific and South Indian Oceans, but over the past 30 years the poleward migration of peak intensity is not seen in Atlantic hurricanes.

The position in peak cyclone intensity has moved poleward as the environment has become more favorable for tropical cyclones in the poleward regions of the tropics... However, the underlying causes for these multi-decadal changes are still unknown,... A poleward expansion of the tropics over this same period, that has been connected, in part, to anthropogenic radiative forcing changes such as stratospheric ozone and greenhouse gas forcing, suggests an influence from anthropogenic forcing in the observed TC expansion.