Weather fronts explained

There are four types of fronts in meteorology. The fronts are warm, cold, stationary, and occluded. There are other boundaries to consider as well, such as a dry line, squall line, and troughs.

A front is basically a dividing line between different air masses or characteristics.

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Cold Front

A cold front is the leading edge or an area of cold air. Colder air will come behind a cold front. Cold fronts are associated with low pressure systems and never high pressure. In the summer months, a cold front can set off severe thunderstorms.

Warm Front

A warm front is the opposite of a cold front, the leading edge or an area of warmer air replacing cold air. Warmer air will come behind a warm front. Warm fronts are associated with low pressure systems and never high pressure.

Stationary Front

A stationary front is just that, stationery. It is not moving. A cold front or warm front that stops moving becomes a stationary front.

Occluded Front

Since cold fronts generally move faster than warm fronts, the fronts can eventually meet. As the fronts meet, the warm air mass is forced up and forms an occlusion.

Dry Line

A dry line marks the separation of a moist air mass and a dry air mass.

Squall Line

A squall line is a line of thunderstorms that forms along a front. The storms are ahead of the front.

Trough

A trough is an area of lower air pressure. There is no difference in the air masses on either side of a trough.