More About Fronts

A few weeks back I did a string of blogs all about fronts.

I just realized I never finished up with the occluded front.

When a cold front catches up to and over takes a warm front, the boundary between the two air masses is called an occluded front.

Or simply, an occlusion.

It is drawn on the surface weather map as a purple line with alternating cold-front triangles and warm front half-circles.

Both symbols point in the direction the air mass is moving.

You can have an occluded front opposite of the one I described above. In otherwords, the warm front can catch up with the cold front, but it isn't as common.