4These weather systems, which are typically many hundred miles across, are referred to by meteorologists as cyclones (around low pressure centers) and anticyclones (around high pressure centers). The flow of air curves around the high or low pressure centers because of the Coriolis effect. For example, as air rushes in to fill a low pressure area its direction gets bent...to the right in the northern hemisphere or to the left in the southern hemisphere, thus setting up a counterclockwise flow in the northern hemisphere, or a clockwise flow in the southern hemisphere. These cyclones should not be confused with tornados, the much smaller intense rotating storms that are sometimes popularly called "cyclones."