Numerical tests for tropical cyclone track prediction by the global WRF model

This work use the global WRF model containing quadruply nesting with which the highest resolution reached 10 km to simulate the typhoons landed on the coast of China in 2011. The model is driven by the reanalysis data fnl with the resolution of 1° x 1°. The study assess the feasibility and applicability of the global WRF model in the 1–7 days prediction of Tropical Cyclone (TC) track by comparing it with the regional WRF model containing the same setting (physical scheme, dynamical frame, model resolution and nesting grid domain). The global model obtain a similar forecast accuracy to the regional model in 1–7 days, with a difference less than 50 km. The forecast accuracy of the global model for 1, 2, 3, 4, 5, 6 and 7 days is about 70 km, 120 km, 180 km, 240 km, 320 km, 400 km, and 500 km, respectively. The reason of the significant TC track errors in the forecast more than 3 or 4 days is analyzed, it is due to the poor representation of typhoon and its steering flow under the situation of binary typhoon system. The study show that the global WRF model can be exploited to proceed the high resolution TC simulation and make the TC track forecast up to 7 days but not in the case of multiple typhoon.