A condition existing when an air mass of lesser density flows or is pushed over by an air mass of greater density. This term is usually applied in the case of warm air ascending the surface of a cold or quasi-stationary front.
A condition where warm moist air rides up an over cooler air at the surface, usually resulting in precipitation.
A condition that exists when an air mass moves up and over a denser air mass on the surface. The result is usually low clouds, fog and steady, light precipitation.
Weather pattern in which a relatively warm air mass is in motion above another air mass of greater density at the surface.
Relatively warm moist air moving above another air mass of greater density (colder air). Embedded thunderstorms sometimes develop in such a pattern; severe thunderstorms (mainly with large hail) can occur, but tornadoes are unlikely.
The flow of warm air over cold air in advance of a warm front.
A condition when warm air overtakes or is lifted by colder denser air.
A condition existing when an air mass is in motion aloft above another air mass of greater density at the surface. This term is applied in the case of warm air ascending the surface of a warm front or quasi-stationary front.
This occurs when a relatively warm air mass is forced above a cooler air mass of greater density. Weather generally associated with this event includes cloudiness, cool temperatures, and steady precipitation.
