The prophase interannual abnormality of the west wind drift area in north Pacific, black current, warm pool and India Ocean are the main signals of the Meiyu abnormality.

• 而前期北太平洋西风漂流区、黑潮、暖池附近及印度洋等海域的海温年际尺度的异常变化是夏季梅雨异常的主要信号区域。