Tropical Cyclone Forecasts in a Next Generation Global Model

A new global model using the GFDL Finite-Volume Cubed-Sphere dynamical core (FV3) coupled to physical parameterizations from the National Center for Environmental Prediction's Global Forecast System (NCEP/GFS) was built at GFDL, called fvGFS. The modern dynamical core, FV3, has been selected for NOAA's Next Generation Global Prediction System (NGGPS) due to its accuracy, adaptability, and computational efficiency, which brings a great opportunity for the unification of weather and climate prediction systems.

The performance of tropical cyclone (TC) forecasts in the 13-km fvGFS is investigated based on 74+ cases of 10-day forecasts in 2015. Track and intensity errors of TCs are compared to those in the operational GFS model which uses same physical parameterizations. The TC intensity in fvGFS is globally outperformed. The forecast skills of TC track are better in fvGFS over East and West Pacific Oceans. More forecast cases are on-going to improve the statistical significance for Atlantic basin. Forecasts of synoptic scale systems (e.g. subtropical high) which affect TC movement will be discussed together with the 500-hPa anomaly correlation between the model forecast and analysis fields.