Comparison of the intensity evolution during Tropical Storms Gabrielle (2001) and Edouard (2002) using the method of point downscaling in a high resolution model

A newly developed technique to simulate tropical disturbances known as point downscaling (Nolan 2011) is employed to compare intensification (or lack thereof) in Tropical Storms Gabrielle (2001) and Edouard (2002). Point downscaling makes modifications to the equations of motion such that high resolution models can maintain relatively constant vertical profiles of temperature, humidity, or wind across a large domain. This allows for a tropical cyclone in the model to be embedded in a homogenous environment making evolutionary analysis simpler.

Simulations of Gabrielle and Edouard are performed using the Weather Research and Forecast (WRF) model in which mean vertical profiles from each storm are interchanged using point downscaling. This allows for insights into why Gabrielle intensified and Edouard did not, though the storms were in similar environments (both storm environments were characterized by shear of 10-13 ms-1 and had SSTs above 29C). We attempt to identify whether intensity differences are due to environmental factors such as adjacent dry air (for example) or if they are due to subtle differences in directional shear.