Occluded Front
When a cold front overtakes a warm front.
A
developing cyclone typically has a preceding warm front
(the leading edge of a warm moist air mass) and a faster
moving cold front (the leading edge of a colder drier
air mass wrapping around the storm). North of the warm
front is a mass of cooler air that was in place before
the storm even entered the region.
As
the storm intensifies, the cold front rotates around
the storm and catches the warm front. This forms an occluded
front, which is the boundary that separates the new cold
air mass (to the west) from the older cool air mass already
in place north of the warm front. Symbolically, an occluded
front is represented by a solid line with alternating
triangles and circles pointing the direction the front
is moving.
Cyclones - major areas affected
