Cold front

Cold front interaction with the warmer air.

Cold front symbol: a blue line with triangles pointing in its movement direction.

A cold front is a meteorological word describing the movement of a cooler air mass into an area of warmer air. The air with greater density moves under the less dense warmer air, lifting it, which can create a line of showers and thunderstorms, or a squall line to form when there is sufficient moisture. This upward motion causes lowered pressure along the cold front.

On weather maps, the surface position of the cold front is marked with the symbol of a blue line of triangles or spikes pointing in the direction of its movement. Cold fronts can also move up to twice as fast as warm fronts.

Precipitation

Rain, snow, hail, and other forms of precipitation can happen with cold fronts.

Effects

Cold fronts can bring dry and colder air behind it. Temperatures can drop to 15 °F behind cold fronts, and it can get very windy.

Cold Front Media

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  A cold front over the eastern and central region of the United States of America

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  An incoming cold front in northern Ohio (2016)

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  Stratocumulus clouds after a cold front

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  Altocumulus clouds often are a sign of an entering cold front.

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  Altocumulus undulatus clouds several hours after a cold front

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  A cold front as it appeared on the National Weather Service Wichita, Kansas WSR-88D on April 3, 2011. The thin blue line labeled "cold front" is the front, with severe thunderstorms seen developing behind the front, which is moving towards the bottom right.

• Strong thunderstorm associated with a cold front in Northern Mexico

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  Occluded cyclone example. The triple point is the intersection of the cold, warm, and occluded fronts.