Cold Fronts 101

Cold fronts are often the main character in the weather story, but what exactly is a cold front? The WBRZ Weather Team is here to answer some common questions about cold fronts.

What is a front?

There are many ways to define a front. If you asked 10 meteorologists this question, you may get 10 different answers. Different types of fronts display different characteristics. In general, a front is a boundary or a transition zone between two different air masses. This zone may be defined by a sharp change in air temperature, a large shift in wind direction, a change in moisture content, or many other atmospheric variables.

What is a cold front?

A cold front divides a warm, moist airmass and a cool, dry airmass. Since warm air rises and cold air sinks, the cooler airmass is the driver behind the cold front. Cooler air acts like a bulldozer to push, lift, and replace the warm air in front of it.

In south Louisiana, cold fronts often present themselves with a drop in humidity, a wind shift, and sometimes a temperature drop.

How do cold fronts form?

Cold fronts are formed as a result of a low pressure center. In the northern hemisphere, air circulates counterclockwise around low pressure. This forces warm air on the south side to move north and cold air on the north side to move south. The cold front typically forms on the western side of the low pressure where the cold air is being forced south.

Why do cold fronts cause storms?

Cold fronts don’t always produce rain, but they do force warm air to rise. If that warm air is also composed of a large amount of water vapor, then it is likely to rain. As the water vapor is forced to rise, it will cool and condense into clouds. Strong lifting will promote rapid condensation and the development of storms.

Have more questions? Email them to weather@wbrz.com!