Use of Three-Dimensional Model Data to Improve Tropical Cyclone Forecasts at the Joint Typhoon Warning Center

Tropical cyclone (TC) intensity prediction remains challenging, especially during periods of rapid intensity change. Operational forecasters are often faced with widely disparate forecasts from various dynamical and statistical models. The Joint Typhoon Warning Center (JTWC) has long used a model consensus approach as the baseline for a given forecast, but consensus forecasts typically have large biases during periods of rapid intensity change. While the suite of operational tools for predicting rapid intensity changes is growing and improving, forecasters often find a need to dig deeper for clues in numerical model data to subjectively calibrate the expected probability of rapid intensification or weakening. A common practice at JTWC is to evaluate model fields in three dimensions to identify TC structures, morphologies, and environmental features known to facilitate (or depress) rapid intensity changes. These techniques may partially explain why the JTWC official forecast outperforms the JTWC intensity model consensus during rapid intensification cases, on average. Here, some examples of these techniques are presented.