Wiktionary
active front
n. (context physics meteorology English) The boundary between two different air masses, or a portion thereof, which produces appreciable cloudiness and precipitation and is usually accompanied by significant shifts in wind direction.
Usage examples of "active front".
Many Elrood citizens feel that IML is an active front for the Empire.
On nearly every active front largo numbers of our forces were either retreating or encircled.
They could deploy relatively few man -- forms to keep the hens in check, and that freed more bats for the active front nearer the harpy flag.
They could deploy relatively few man forms to keep the hens in check, and that freed more bats for the active front nearer the harpy flag.