Relative Timing of the Ends of Hurricane Intensification and Contraction of the Radius of Maximum Wind in the North Atlantic and Eastern North Pacific

The statistical relationship between the ending times of hurricane intensification and contraction of the radius of maximum wind (RMW) over the North Atlantic (NA) and Eastern North Pacific (EP) is assessed using the Extended Best Track and Tropical Cyclone Observations-Based Structure databases during 1999-2014. Results show that in more than half of hurricanes the end of RMW contraction precedes the end of intensification, and those hurricanes generally have lower relative intensity (intensity normalized by the corresponding maximum potential intensity) and larger curvature of the tangential wind profile at the RMW. The preceding time tends to be longer with lower relative intensity and lower intensification rate and on average is longer in the NA (similar to 19 hr) than in the EP (similar to 12 hr) due to the overall lower intensification rate in the former. These findings can help improve our understanding of hurricane structure and intensity changes.