Note:  The hash mark will always be drawn perpendicular to the boundaries.  They are not drawn at "triple points" (the intersection of an occluded, cold and warm or stationary front) and where a low pressure center separates the different frontal types.

Frontogenesis refers to the initial formation of a surface front or frontal zone, while frontolysis is the dissipation or weakening of a front.   Frontogenesis is depicted on HPC's surface analysis and forecast charts as a dashed line with the graphical representation of the developing frontal type (the blue triangle for cold fronts, the red semicircle for warm fronts, etc...) drawn on each segment.   For example, the image below shows a forming cold front.

Frontolysis is depicted as a dashed line with the graphical representation of the weakening frontal type drawn on every other segment.  Below is an example of a dissipating warm front.