An idealized model of cyclonic eddy circulation in North America. On weather maps, warm fronts are depicted by a red solid line with semi-circles that point towards the cooler air. Cold fronts are depicted by a solid blue line with triangles that point towards the cooler air. Cyclones are an area of low pressure (marked by the L) around which airflows counterclockwise on the northern hemisphere. The warm front is pushing northward and a cold front is pulling southward.