The prediction capability of dominant daily monsoon modes of Indian summer monsoon in the forecast of the Global Forecast System Version 2 (GFSv2) model is scrutinized. The dominant monsoon modes are procured by performing the multichannel singular spectrum analysis (MSSA) on daily precipitation anomalies of the Indian summer monsoon region (60–100°E, Eq.-35°N) during 2001–2014. The observation has one seasonally persistent mode and two intraseasonal oscillations with periods around 42 and 26 days, and the model has correctly simulated these modes. The spatial structure of the phase composites of the precipitation anomalies of the intraseasonal modes of the model is almost similar to the observed spatial pattern with slightly less magnitude of the precipitation anomalies over Western India and the core monsoon zone. The spatial structure of the 26-day mode is similar to the spatial structure of the 42-day mode with less magnitude of the precipitation anomalies all over the study domain. The lead forecast of the model demonstrates the robust predictive skill of intraseasonal modes. The variation of the active and break spells of monsoon precipitation over the Indian subcontinent is captured accurately by the contribution of both intraseasonal modes. The observed eastward and northward propagation features of the Indian summer monsoon have been accurately simulated by the model. The model has weak seasonally persistent signals over Western India, northeast India, and eastern land regions adjacent to the Western Ghats. The seasonally persistent mode shows a strong relationship with the equatorial central Pacific Ocean SSTs and a moderate correlation with the Indian and Atlantic Ocean SSTs. The seasonally persistent mode contributes largely to the seasonal precipitation anomalies over the Indian monsoon region.

在全球预报系统第2版（GFSv2）模型的预报中，对印度夏季风的主要日季风模式的预测能力进行了仔细检查。主要的季风模式是通过对2001–2014年印度夏季风区域（60–100°E，Eq.-35°N）的每日降水异常进行多通道奇异谱分析（MSSA）而获得的。该观测值具有一个季节持续模式和两个季节内振荡，周期分别为42天和26天，并且该模型已正确模拟了这些模式。该模型的季节内模式降水异常的相复合物的空间结构几乎与所观测到的空间模式相似，印度西部和核心季风区的降水异常幅度较小。26天模式的空间结构类似于42天模式的空间结构，整个研究领域的降水异常幅度较小。该模型的先导预测证明了季节内模式的强大预测能力。通过两个季节内模式的贡献，可以准确地捕捉到印度次大陆上季风降水的活跃期和中断期的变化。该模型已准确地模拟了印度夏季风向东和向北的观测到的传播特征。该模型在印度西部，印度东北部和西高止山脉附近的东部陆地地区具有弱的季节性持续信号。季节性持续模式显示与赤道中部太平洋海表温度有很强的关系，而与印度洋和大西洋海表温度有中等的相关性。季节性持续模式在很大程度上影响了印度季风区域的季节性降水异常。