Wiktionary
n. (context meteorology English) The boundary between two masses of air of different density and/or temperature
Wikipedia
A weather front is a boundary separating two masses of air of different densities, and is the principal cause of meteorological phenomena. In surface weather analyses, fronts are depicted using various colored triangles and half-circles, depending on the type of front. The air masses separated by a front usually differ in temperature and humidity. Cold fronts may feature narrow bands of thunderstorms and severe weather, and may on occasion be preceded by squall lines or dry lines. Warm fronts are usually preceded by stratiform precipitation and fog. The weather usually clears quickly after a front's passage. Some fronts produce no precipitation and little cloudiness, although there is invariably a wind shift.
Cold fronts and occluded fronts generally move from west to east, while warm fronts move poleward. Because of the greater density of air in their wake, cold fronts and cold occlusions move faster than warm fronts and warm occlusions. Mountains and warm bodies of water can slow the movement of fronts. When a front becomes stationary, and the density contrast across the frontal boundary vanishes, the front can degenerate into a line which separates regions of differing wind velocity, known as a shearline. This is most common over the open ocean.
Usage examples of "weather front".
Rather fast, he thought, remembering they'd landed in clear skies and hadn't even seen a weather front moving in on their approach from the west.
She was a toucher and kidder, obviously well loved by the two Glenns, the kind of woman who excels at picnicslaughing and telling jokes, slapping men's backs, pinching the kids, matching bosoms with the ladies, a vast warm-weather front moving across the plains.
The sky was slung across with the ugly underbelly of a massive foul-weather front, the clouds churning and coiling as they raced across the water.
The aircab took the winding turn through Maze Gap that would lead to Klameth Canyon, dipping and bumping as they encountered turbulent air at the edge of the weather front that had left Madison socked in beneath rain clouds.
The pilot requests that you be ready, madame, as he would like to fly ahead of the weather front moving east.
Ahead of them, stretching out of sight from side to side was a small weather front.