•When two unlike air masses remain side by side, with neither encroaching upon the other, a stationary front exists.
•The cold air on the north side of the
front is moving
parallel to the front, while the warm air to the south moving toward the front and get lifted along the frontal boundary.
•If the warm air is conditionally unstable,
a line of
showers and thunderstorms may develop in the warm side of the front.
•If the warm air is stable, widespread layered clouds may form over the front, with rain falling on the cold side of the front.