 However, since the lower level moisture flow is not as persistent as in the Indian monsoon, the upper level steering pattern and disturbances around the ridge are critical for influencing where thunderstorms develop on any given day.The exact strength and position of the subtropical ridge also governs how far north the tropical easterly winds aloft can spread.If the ridge is too close to a particular area, the sinking air at its center suppresses thunderstorms and can result in a significant monsoon "break."