A High-Resolution Coupled Model Study of the Rapid Intensification of Hurricane Harvey 2017

The hurricane Harvey in 2017 rapidly intensified from a tropical storm to category 4 hurricane within 32 hours to become the tropical system with the higher rainfall. After hurricane Wilma in 2005, hurricane Harvey was the first major hurricane (category 3 or higher) to make landfall in the US. Compared to the past hurricanes in the Gulf of Mexico, which typically intensify in the open ocean region and weakens near the coast, the hurricane Harvey intensified close to the coastal region. Also, even after making the first landfall, hurricane Harvey maintained hurricane strength for two more days. Oceanic and atmospheric processes leading to rapid intensification of hurricanes are not fully understood yet and remains as an active topic of research.

In this study, we use a convection resolving high-resolution atmosphere-ocean coupled model to study the rapid intensification of hurricane Harvey 2017. Control simulation using atmosphere-ocean condition during hurricane Harvey 2017 reproduces the observed rapid intensification and the rapid weakening of the hurricane. Model is capable of accurately simulating the accumulated hurricane rainfall over the eastern Texas region. The importance of upper ocean heat content will be examined using sensitivity experiments with lower upper ocean heat content but with sea surface temperature similar to that during the hurricane. Detailed heat budget analysis will be used for estimating exchange of heat between ocean and atmosphere during the hurricane. Two different schemes for the computation of air-sea fluxes will be compared to decide which of them reproduce the observed features of hurricane more realistically.