The North Atlantic passes through a temperate climate zone in the Northern Hemisphere, far from the Equator. This is a low pressure zone with cold waters. Depression storms are frequent, bringing rain to the United Kingdom and Europe, as warm air currents from the subtropics meet cold air and form cold fronts. Icebergs have been known to drift into the North Atlantic from Greenland.
The weather here is hot and dry with little rain fall. In the transitional period of late spring in the Northern Hemisphere, warm and cold air masses clash and form tropical storms in the subtropics. These storms transpose into fully fledged tornadoes hitting south central United States, known as tornado alley, as well as Florida.
The tropics is dominated by the Intertropical Convergence Zone, a strip of hot rising air that hovers around the Equator. Hot rising air and strong trade winds make for torrential rain and almost daily thunderstorms, e.g., southern Nigeria. The Tropics dictate the weather around the western coast of southern Africa in the subtropics, resulting in monsoons or drought.Five degrees north and south of the Equator, the earth's rotational force is low, (Coriolis force) --strong wind vortexes rarely form. Hurricanes in the North Atlantic are not known to cross over the equator into the Southern Hemisphere. This means storms in the Equatorial Atlantic are short lived while full-blown tropical tornadoes and hurricanes are a freak occurrence.
At the Southern Hemisphere end of the Atlantic, hurricanes and tornadoes are unusual; strong prevailing winds, called trade winds, break up storms before they gather momentum and there is no Intertropical Convergence Zone to stimulate vortex winds. The trade winds produce choppy waves and short-lived storm activity. The South Atlantic surface temperature is cold and disperses into the turbulent Drake Passage.
