Frequently Asked Questions (FAQ)

Climatology | Impacts | Extremes| TCs affecting WA towns | Forecast Accuracy
Frequently Asked Questions | Annual summaries

Definitions | Characteristics and Formation | Climatology | Extremes | Forecasting | More Information

Definitions

1. What is a tropical cyclone?

A tropical cyclone is defined as a non-frontal low pressure system of synoptic scale developing over warm waters having organised convection and a maximum mean wind speed of 34 knots or greater extending more than half-way around near the centre and persisting for at least six hours.

Every cyclone is unique varying according to a number of factors including life cycle, intensity, movement, size and impact (wind, storm surge and flooding).

Satellite image of cyclone Kalunde showing a well developed eye surrounded by the eye wall and spiral bands of convection.