A weather front is a boundary separating two masses of air of different densities, and is the principal of them meeting but not mixing. In surface weather analyses, fronts are depicted using various colored triangles and half-circles, depending on the type of front.
A cold front is when the boundary of an advancing mass of cold air (high-pressure system) and the warm air (low-pressure system) meet but don't crossover and the cold air pushes and forces the warm air up. A cold front is defined as the transition zone. Cold fronts generally move from northwest to southeast.
A stationary front is a pair of air masses, neither of which is strong enough to replace the other. On a weather map, this is shown by an inter-playing series of blue spikes pointing one direction and red domes pointing the other. The molecules in a staitionary as the warm air mass rises, it condenses into a broad area of clouds. A warm front brings gentle rain or light snow, followed by warmer, milder weather. Stationary front Forms when warm and cold air meet and neither air mass has the force to move the other. They remain stationary, or “standing still.”