An evaluation and comparison of predictions of tropical cyclogenesis by three global forecast models

There have been continued enhancements to resolution and physics in global numerical weather prediction models at the various forecast centers. These advances have led, presumably, to continued improvements in the models' forecasts of weather over the tropics, in particular, forecasts of tropical cyclone (TC) formation. This study will evaluate recent forecasts of tropical cyclogenesis made by the National Centers for Environmental Prediction's Global Forecast System, the United States Navy Operational Global Atmospheric Prediction System, and the United Kingdom Meteorological Office Global Model. For our methodology, we utilize an objective TC vortex identification and tracking technique, which enables the determination of statistics such as probability of detection and false alarm rates of tropical cyclogenesis in the model fields. Furthermore, forecasts of several physical quantities relevant to TC formation (e.g., warm core magnitude, vertical wind shear, mid-level moisture, etc.) are evaluated with respect to each tropical vortex that is correctly and incorrectly forecast to become a TC. A comparison of the three model's performance in predicting TC formation during the 2005 hurricane season will be presented.