Coastal Skipper and Yachtmaster Quiz · Meteorology
This front carries triangles and semicircles together. How does a front like this form?
A weather chart. A purple line curves away from a low, marked L. Along its leading side, triangles and semicircles alternate one after the other.
Show the answer
The cold front catches up with the warm front and lifts the warm air off the surface. This is an occluded front. A cold front travels faster than the warm front ahead of it, so late in the life of a depression it catches up and the warm sector air is lifted clear of the surface. An occlusion usually marks a depression that is mature and beginning to fill, though it can still bring a belt of rain and a wind shift.
