Using calculating circulation parameters, classifying circulation patterns and spreading polynomials, the methods for forecasting the day and durationof continuous overcast and rainy days have been establised.

• 利用对大气环流特征参量的计算和环流分型及车贝雪夫多项式展开等方法，建立不同时间尺度的预报方法，预测连阴雨的发生时间及长度。