Air masses, fronts, and extratropical cyclones are meteorological systems that commonly affect the weather in South America, including Brazil. The passage of a cold front through a particular region can cause, for example, cloudiness, precipitation, and abrupt variations in air temperature.
As these systems have a significant impact on people's daily lives and are often topics covered in the media, this article aims to contribute to the dissemination of the conceptual characteristics of these systems, introduce the definition of some atmospheric variables commonly used in their identification, and apply these definitions to atmospheric data in a case study of an extratropical cyclone.