Changes in Track Characteristics of Tropical Cyclones Near Landfall: A Review

Understanding the physical mechanisms responsible for changes in the movement of a tropical cyclone (TC) near landfall is important in improving the prediction of its landfall location.Although the general physical processes governing the TC movement have been quite well documented, very few previous studies focused on the situation when a TC is about to make landfall.This review provides a summary of the major observational and numerical model results that address how a TC track may change before the TC makes landfall. As a TC approaches a coastline, differences in surface mechanical and thermodynamic properties between a land surface and an open ocean will lead to momentum and heat fluxes associated with part of the TC circulation over land to be different from the other part that is over the ocean. Such differences result in asymmetries in divergence/convergence, vertical motion, relative vorticity, and convection, which subsequently would change the potential vorticity tendency, and hence TC motion. In general, the TC tends to move towards the area with higher roughness and accelerate towards the coastline.While some of these results need to be further verified, they highlight two important areas of improvement in numerical prediction of the track of landfalling TCs. These include an accurate land surface cover to provide the correct surface properties in the model. Better boundary-layer parameterization schemes should also be investigated to have a more accurate representation of the air-land interaction processes.