Assessing the Influence of the ENSO on Tropical Cyclone Prevailing Tracks in the Western North Pacific

Using a statistical model for simulating tropical cyclone (TC) formation anda trajectory model for simulating TC tracks, the influence of the ElNino-Southern Oscillation (ENSO) on the peak-season (July--September) TCprevailing tracks in the western North Pacific basin is assessed based on 14selected El Nino and 14 selected La Nina years during the period 1950--2007.It is found that the combination of statistical formation model and atrajectory model can simulate well the primary features of TC prevailingtracks on the interannual timescale. In the El Nino years, the significant enhancement of TC activity primarily occurs south of 20N, especially east of 130E. TCs that take the northwestward prevailing track and affect East Asia, including Taiwan Island, the Chinese mainland, Korea, and Japan, tend to move more westward in the El Nino years, while taking a more northward track in the La Nina years. Numerical simulations confirm that the ENSO-related changes in large-scale steering flows and TC formation locations can have a considerable influence on TC prevailing tracks.