A line with solid semicircles along one side, marking advancing warm air.
Also known as: Warm front, Line with bumps, Half circles on a weather map
Rounded bumps along a line mark a warm front. The bumps point the way it is moving, and their roundness is what tells them from the cold front's triangles when the chart is printed in black and white.
Marks the leading edge of advancing warm air, with the semicircles on the side the front is moving towards.
Contexts: Navigation
Brings a slower, longer period of rain than a cold front, because warm air rises gradually over the cold air it displaces rather than undercutting it.
Contexts: Navigation
A curved line with solid semicircles spaced along it, all on the same side and all bulging away from the line in the direction of travel.
Advancing warm air against advancing cold air.