<p>Typhoon forecast of Global Spectral Model of Japan Meteorological Agency (JMA-GSM, GSM hereafter) using a new spectral cumulus parameterization (spectral scheme) is evaluated through forecast experiments and comparison with the original GSM convection scheme. The experiments were conducted for two typhoons, Prapiroon (2018) and Hagibis (2019). In the Prapiroon case, the spectral scheme improves both the typhoon track and minimum pressure errors. In the Hagibis case, the spectral scheme significantly reduces the minimum pressure error but increases the track error. In both cases, the spectral scheme generally improves the pressure fields around the typhoon after initialization. However, in the Hagibis case, the spectral scheme predicts a rapid decrease in minimum pressure at the typhoon center to fill the discrepancy between the initial and model-preferred conditions, inducing a pressure perturbation behind the track that enhances the easterly wind. An ensemble singular vector sensitivity analysis suggests that this easterly wind eventually shifts the typhoon westwards, resulting in the track error. It is concluded that the spectral scheme has the potential to improve the typhoon forecast of the GSM by improving the pressure patterns, but updates in generating the initial condition should be considered to achieve further improvements.</p>