nose

A colloquial way of referring to the lower part of the cold frontal surface. As a whole, it takes the shape of a wedge, with an approximate slope of 2% (significantly greater than that of the warm frontal surface, which is approximately 0.6%). In the vicinity of the ground, over dry land, the cold frontal surface presents a rounded shape, of appearance very similar to that of a nose. This is how that zone of separation between the two air masses is graphically represented. The deformation of the wedge at its lower part is a consequence of the friction of the cold air with the ground, which slows its advance.