A front that shows little or no horizontal motion. By convention, the term is applied to any front that is moving at less than 5 knots. In synoptic meteorology, a front that has not changed its position appreciably since the last synoptic chart was prepared, three or six hours previously. The slow horizontal motion, combined with considerable vertical motion of the warm air, often gives rise to persistent and sometimes extreme amounts of precipitation, leading to flooding or major snow or ice storms.
Subjects: Meteorology and Climatology.