The circulation of air around large, low-pressure masses.
a weather system that includes a well-defined surface low-pressure area and associated warm, cold, and occluded fronts
see extratropical cyclone
a storm associated with a low pressure cell in the mid-latitudes.
Cyclonic storm that forms primarily in the middle latitudes. Its formation is triggered by the development of troughs in the polar jet stream. These storms also contain warm, cold and occluded fronts. Atmospheric pressure in their center can get as low as 970 millibars. Also called wave cyclones or frontal cyclones.