I am trying to understand the Coriolis effect from some time but i am unable to conceive the idea why the air parcel flowing from west to east on Earth would go southward. what I have understood till now is: " From the perspective of observer in inertial frame of reference, when the air parcel goes from South to North in Northern hemisphere, the direction of net velocity of the parcel is given as the resultant of its tangential velocity, and the vertical component of velocity. If we ignore friction, the parcel should continue to move in the direction specified by the resultant velocity, which is to the East of North. Similarly, the air parcel rushing from North to South would move in the direction of the resultant velocity, which is to the West of South." When I think the same way for the air parcel from West or East, it is obvious that there should be no apparent deflection in the parcel because there is no vertical component of velocity. Please tell me what is wrong with my interpretation.