Why do planetary winds not blow directly north or south?

Planetary winds do not blow directly north or south due to the Coriolis effect, which is caused by the Earth's rotation. As air moves from high to low pressure, the rotation of the Earth causes the winds to be deflected to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. This deflection results in the winds generally flowing in a more east-west direction, creating prevailing wind patterns such as the trade winds and westerlies. Consequently, the winds follow a curved path rather than a straight north-south trajectory.