The South African Weather Service frequently issues impact-based weather warnings, often accompanied by colour codes and severity levels, but what do these alerts actually signify?
An impact-based warning system is designed to inform the public not just about expected weather conditions, but about the potential consequences those conditions may have. Unlike traditional forecasts that focus on what the weather will be, this approach highlights what the weather is likely to do.
The system uses a colour-coded and numbered risk matrix to classify warnings. These levels are determined by combining two key factors: the severity of the expected impact and the likelihood of that impact occurring.
For example, a red Level 10 warning “the highest on the scale” indicates a very high probability of severe and potentially dangerous impacts. Such conditions could pose significant risks to life, infrastructure and essential services.
Authorities urge the public to pay close attention to these warnings, as they are intended to support preparedness and reduce the risks associated with extreme weather events.