Coriolis force doesn't really exist. It's a compensation due to our frame of reference viz. We're relating the airmass movement to a constantly revolving platform - the Earth's surface.
The effect can be shown by making a circle & rotating it (representing the Earth viewed from above a pole). Centre of the circle is of course the pole, circumference is the equator.
Rotate the circle West to East while moving a pen in a straight line from pole to circumference. Do the same again from circumference to pole. Do it again at some diagonal. The pen represents an air mass.
Each time, the line will curve as seen on the circle even though the movement of the pen (the 'airmass') was straight.
The impetus that sets the air mass in motion is a pressure differential. Any time there is N-S component in the velocity then this effect will be seen.
Even an E-W movement will eventually have a N-S component eg Highs/Lows to the N or S.