Recent Improvements to NHC's Statistical-Dynamical Tropical Cyclone Intensity Prediction Models

The National Hurricane Center (NHC) utilizes a suite of dynamical and statistical-dynamical guidance models for tropical cyclone intensity forecasting. The statistical-dynamical models include the Statistical Hurricane Intensity Prediction Scheme (SHIPS) and the Logistic Growth Equation Model (LGEM). Recent improvements to SHIPS and LGEM are described, including the use of the Climate Forecast System Reanalysis (CFSR) for model training, and improving the deterministic prediction of rapid intensification by coupling LGEM with the probabilistic Rapid Intensification Index (RII). As the resolution of the parent global models continues to increase, the depiction of tropical cyclones improves. As a result, new methods are needed to better isolate the environment in some of the model diagnostics. Although an algorithm to remove the symmetric wind circulation from the global fields has been utilized in SHIPS and LGEM for the past several years, no adjustment was made to the temperature field. To address this issue, a new method to remove the warm core signature of the tropical cyclone from the surrounding temperature environment using the gradient thermal wind has been developed. Several additional improvements are planned in the near future, including a more general method for estimating the potential intensity, use of higher resolution sea surface temperature fields, and a more physically-based method to account for ocean cooling due to mixing and up-welling. The details and potential impact of each development will be presented.

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