Weather Fronts

Weather Fronts Formed when air masses with different characteristics collide. It is defined as the narrow region separating two air masses of different densities. D differences are caused by differences in T, P and humidity. Types are: cold fronts, warm fronts, stationary fronts, and occluded fronts.

cold front – cold, dense air displaces warm air and forces the warm air up along a steep front. Clouds, showers, and thunderstorms Represented on weather map by solid blue arrows

warm front – advancing warm air pushes away cold air. Extensive cloudiness and precipitation. On weather map, shown as solid semicircles

stationary front – sometimes two air masses meet and neither advances into the other’s territory, and the air masses stall. Rarely have clouds and heavy precip. Represented on weather map by solid blue arrows (cold front) and solid red semicircles (warm front) in directions of the two fronts.

occluded front – sometimes a cold air mass moves so fast that it passes a warm front. Advancing cold air pushes the warm air upward. Precipitation is common Represented on weather map by alternating purple triangles and semicircles