The seasonal predictability of tropical cyclones (TC) in the western North Pacific (WNP) reported in previous studies are mainly based under the general consideration that the WNP is homogeneous in terms of its spatial and temporal characteristics. Here we present evidence that the western (Domain 1) and eastern (Domain 2) parts of the WNP exhibit spatial and seasonal asymmetric response to large-scale environments (e.g., asymmetrical sea surface temperature anomalies distribution) leading to distinct spatial and seasonal TC variability in the said domains. Exploring such asymmetries, we propose an alternative approach on the long-range predictability of TC genesis frequency in the WNP during its active TC season (i.e., June-November, JJASON) by separately predicting the TC genesis frequency in two domains (i.e., Domains 1 and 2) in two distinct seasons (i.e., June-August and September-October), respectively. Using a number of climate indices as predictors in different lead times, our regression-based models present its best significant seasonal predictability of TC genesis frequency during JJASON (i.e., r = 0.80, p < 0.01) that essentially captures the spatial and seasonal asymmetry in the WNP. It is expected that this study provides valuable insights on the long-range and more localized TC prediction in support of disaster risk reduction in the WNP region.

以往研究报道的西北太平洋热带气旋(TC)季节可预报性主要基于西北太平洋热带气旋时空特征均一性的普遍考虑。在这里，我们提供的证据表明，西太平洋国家公园的西部（域1）和东部（域2）对大尺度环境表现出空间和季节不对称响应（例如，不对称的海面温度异常分布），导致明显的空间和季节TC变化在上述领域。为了探索这种不对称性，我们提出了一种替代方法，通过分别预测两个域（即域）中的 TC 发生频率，来长期预测 WNP 在其活跃的 TC 季节（即 6 月至 11 月，JJASON）中的 TC 发生频率。 1和2）分别在两个不同的季节（即6月至8月和9月至10月）。使用多个气候指数作为不同提前期的预测因子，我们的基于回归的模型呈现了 JJASON 期间 TC 发生频率的最佳显着季节可预测性（即r  = 0.80，p  < 0.01），基本上捕获了 JJASON 期间的空间和季节不对称性。西北民族党。预计这项研究将为长期和更本地化的TC预测提供有价值的见解，以支持WNP地区减少灾害风险。