If there should be a fall of rain when the Moon passes through the asterisms of Pūrvabhādrapada and Puṣya in the lunar month of Jyeṣṭha , the quantity of rainfall in the coming winter will be 15 droṇas ; if when through Aśvinī , the quantity will be 12 droṇas ; if when through Ārdrā , it will be 18 droṇas . In all the above cases, the subsequent rainfall depends upon the asterisms remaining unaffected by comets, meteors and the like from the month of Jyeṣṭha to the rainy season.