A warm front is a density discontinuity located at the leading edge of a homogeneous warm air mass, and is typically located on the equator-facing edge of an isotherm gradient. Warm fronts lie within broader troughs of low pressure than cold fronts, and move more slowly than the cold fronts which usually follow because cold air is denser and less easy to remove from the Earth's surface. This also forces temperature differences across warm fronts to be broader in scale.
Clouds ahead of the warm front are mostly stratiform, and rainfall gradually increases as the front approaches. Fog can also occur preceding a warm frontal passage. Clearing and warming is usually rapid after frontal passage. If the warm air mass is unstable, thunderstorms may be embedded among the stratiform clouds ahead of the front, and after frontal passage thundershowers may continue. On weather maps, the surface location of a warm front is marked with a red line of semicircles pointing in the direction of travel.
Read more about Warm Front: Development, Characteristics, Warm Sector, Depiction
Famous quotes containing the words warm and/or front:
“But with some small portion of real genius and a warm imagination, an author surely may be permitted a little to expand his wings and to wander in the aerial fields of fancy, provided ... that he soar not to such dangerous heights, from whence unplumed he may fall to the ground disgraced, if not disabled from ever rising anymore.”
—Sarah Fielding (1710–1768)
“Drug misuse is not a disease, it is a decision, like the decision to step out in front of a moving car. You would call that not a disease but an error of judgment.”
—Philip K. Dick (1928–1982)