. Given the direction of the winds around an anticyclonic circulation and the fact that weather systems move from west to east: • ahead of an upper-ridge, the airflow that comes from the polar regions and brings cold air. • behind the upper-ridge line, the flow that comes from the equator and brings mild air. Surface ridges, just like highs, generate fair weather because they develop under wind convergence in the
negative vorticity advection zone ahead of the upper-level ridge. The air descending from the upper troposphere flows out from its center at surface level toward the upper and lower latitudes of each hemisphere, creating both the
trade winds and the
westerlies. It helps steer
tropical cyclones and the
monsoon.
Ridge blocking Blocks in
meteorology are large-scale patterns in the
atmospheric pressure field that are nearly stationary, effectively "blocking" or redirecting migratory
cyclones. These blocks can remain in place for several days or even weeks, causing the areas affected by them to have the same kind of weather for an extended period of time (e.g. precipitation for some areas, clear skies for others). Upper ridges are often associated with such blocks, particularly in
Omega blocks. == References ==