The Westerlies, prevailing westerlies, or anti- trades, are winds from the west towards the east in the middle latitudes between 30 and 60 degrees’ latitude. They move towards the poles and steer extratropical cyclones in this general manner and originate from the high-pressure areas in the horse latitudes. These winds are predominantly from the northwest in the southern hemisphere and from the southwest in the northern hemisphere.
The westerlies are weakest in the summer hemisphere and when the pressure is higher over the poles and the strongest in the winter hemisphere and when the pressure is lower over the poles. The westerlies are significantly strong in the Southern hemisphere because geographically most of the surface areas of the southern hemisphere are occupied by huge water bodies i.e. all the big oceans, and comparatively this region has lesser landmass than the Northern hemisphere. And since the human occupancy in the northern hemisphere is more than the southern hemisphere, it has severely disturbed the global air-conditioning system of the Earth and also has misbalanced the ecological, climatic, and biological conditions on the northern hemisphere more than that of the southern hemisphere.
Since these impacts are less in the southern hemisphere and the passage of the westerlies is hardly disturbed by these impediments, the ocean currents and periodic winds are naturally spontaneous with the seasonal changes. While the geophysical conditions and the natural phenomena of the northern hemisphere are not the same.
Thus, in the southern hemisphere, westerlies are stronger and steadier.
The strongest westerly winds can come in the roaring forties, between 40 and 50 degrees’ latitude, in the middle latitudes.