<P> A cold front would be seen as spikes and a warm front as semi-circles in a traditional weather map . An occluded front, is a combination of those two signs . They are indicated on a weather map either by a purple line with alternating semicircles and triangles pointing in direction of travel, or by red semicircles and blue triangles pointing in the same direction . On the other hand, trowal are indicated by junction of blue and red lines like the junction of cold and warm fronts aloft . </P> <P> A wide variety of weather can be found along an occluded front, with thunderstorms possible, but usually their passage is associated with a drying of the air mass . Additionally, cold core funnel clouds are possible if shear is significant along the cold front . Small isolated occluded fronts often remain for a time after a low pressure system has decayed and these create cloudy conditions with patchy rain or showers . </P> <P> However, the clouds and precipitation are not really where the projection on the Earth's surface of the occluded front is, but with the trowal position . </P>

Difference between cold front occlusion and warm front occlusion