text: on a weather map, what is a purple line with either dashed lines or triangles and circles represent? i know that blue triangles represent a cold front, red circles represent a warm front, i think i've heard that the mix between a cold and warm front represents an arctic front, but i would like to know what a purple line with either a dashed line or triangles and circles represents. the purple line with triangles and circles is called an occluded front. in simple terms it is where a cold front has caught up with a warm front.