Numerical simulations of the genesis of Hurricane Gabrielle (2001)

Previous research conducted by the authors of the formation of Hurricane Gabrielle (2001) indicated that reducing the vertical shear over the developing system produced a weaker tropical cyclone. That research simulated the formation of Gabrielle and included sensitivity experiments. One of those experiments reduced the vertical wind shear over Gabrielle's precursor disturbance, and produced a weaker version of Gabrielle than was seen in the control run. Those simulations were run with the fifth-generation Pennsylvania State University-National Center for Atmospheric Research mesoscale model (MM5). The innermost domain had a horizontal resolution of approximately 12 km, necessitating the use of a cumulus parameterization, for which the authors chose the Kain Fritsch parameterization.

For the current research the authors conducted further simulations with MM5, to test the robustness of the original results based on the idea that the convection is important to the processes allowing the vertical shear to assist in Gabrielle's formation. These simulations examined the effects of applying different parameterizations to the original results, and included finer-resolution simulations to examine the effects of explicit cumulus convection.